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Zhang L, Wang C, Zhang C, Xue Y, Ye Z, Xu L, Hu Y, Li J, Chu J, Wu D. High-Throughput Two-Photon 3D Printing Enabled by Holographic Multi-Foci High-Speed Scanning. NANO LETTERS 2024; 24:2671-2679. [PMID: 38375804 DOI: 10.1021/acs.nanolett.4c00505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/21/2024]
Abstract
The emerging two-photon polymerization (TPP) technique enables high-resolution printing of complex 3D structures, revolutionizing micro/nano additive manufacturing. Various fast scanning and parallel processing strategies have been proposed to promote its efficiency. However, obtaining large numbers of uniform focal spots for parallel high-speed scanning remains challenging, which hampers the realization of higher throughput. We report a TPP printing platform that combines galvanometric mirrors and liquid crystal on silicon spatial light modulator (LCoS-SLM). By setting the target light field at LCoS-SLM's diffraction center, sufficient energy is acquired to support simultaneous polymerization of over 400 foci. With fast scanning, the maximum printing speed achieves 1.49 × 108 voxels s-1, surpassing the existing scanning-based TPP methods while maintaining high printing resolution and flexibility. To demonstrate the processing capability, functional 3D microstructure arrays are rapidly fabricated and applied in micro-optics and micro-object manipulation. Our method may expand the prospects of TPP in large-scale micro/nanomanufacturing.
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Affiliation(s)
- Leran Zhang
- CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei 230026, China
| | - Chaowei Wang
- CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei 230026, China
| | - Chenchu Zhang
- Anhui Province Key Lab of Aerospace Structural Parts Forming Technology and Equipment, Institute of Industry & Equipment Technology, Hefei University of Technology, Hefei 230009, China
| | - Yuhang Xue
- CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei 230026, China
| | - Zhaohui Ye
- CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei 230026, China
| | - Liqun Xu
- CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei 230026, China
| | - Yanlei Hu
- CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei 230026, China
| | - Jiawen Li
- CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei 230026, China
| | - Jiaru Chu
- CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei 230026, China
| | - Dong Wu
- CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei 230026, China
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2
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Salter P, Villar MP, Lloret F, Reyes DF, Krueger M, Henderson CS, Araujo D, Jackman RB. Laser Engineering Nanocarbon Phases within Diamond for Science and Electronics. ACS NANO 2024; 18:2861-2871. [PMID: 38232330 PMCID: PMC10832029 DOI: 10.1021/acsnano.3c07116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 01/10/2024] [Accepted: 01/11/2024] [Indexed: 01/19/2024]
Abstract
Diamond, as the densest allotrope of carbon, displays a range of exemplary material properties that are attractive from a device perspective. Despite diamond displaying high carbon-carbon bond strength, ultrashort (femtosecond) pulse laser radiation can provide sufficient energy for highly localized internal breakdown of the diamond lattice. The less-dense carbon structures generated on lattice breakdown are subject to significant pressure from the surrounding diamond matrix, leading to highly unusual formation conditions. By tailoring the laser dose delivered to the diamond, it is shown that it is possible to create continuously modified internal tracks with varying electrical conduction properties. In addition to the widely reported conducting tracks, conditions leading to semiconducting and insulating written tracks have been identified. High-resolution transmission electron microscopy (HRTEM) is used to visualize the structural transformations taking place and provide insight into the different conduction regimes. The HRTEM reveals a highly diverse range of nanocarbon structures are generated by the laser irradiation, including many signatures for different so-called diaphite complexes, which have been seen in meteorite samples and seem to mediate the laser-induced breakdown of the diamond. This work offers insight into possible formation methods for the diamond and related nanocarbon phases found in meteorites.
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Affiliation(s)
- Patrick
S. Salter
- Department
of Engineering Science, University of Oxford, Parks Road, Oxford, OX1 3PJ, U.K.
| | - M. Pilar Villar
- Department
of the Science of Materials, University
of Cadiz, 11510, Puerto Real, Spain
| | - Fernando Lloret
- Department
of the Science of Materials, University
of Cadiz, 11510, Puerto Real, Spain
| | - Daniel F. Reyes
- Department
of the Science of Materials, University
of Cadiz, 11510, Puerto Real, Spain
| | - Marta Krueger
- Department
of Engineering Science, University of Oxford, Parks Road, Oxford, OX1 3PJ, U.K.
| | - Calum S. Henderson
- London
Centre for Nanotechnology and Department of Electronic and Electrical
Engineering, UCL (University College London), 17−19 Gordon Street, London, WC1H 0AH, U.K.
| | - Daniel Araujo
- Department
of the Science of Materials, University
of Cadiz, 11510, Puerto Real, Spain
| | - Richard B. Jackman
- London
Centre for Nanotechnology and Department of Electronic and Electrical
Engineering, UCL (University College London), 17−19 Gordon Street, London, WC1H 0AH, U.K.
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3
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Kratz M, Rückle L, Kalupka C, Reininghaus M, Haefner CL. Dynamic correction of optical aberrations for height-independent selective laser induced etching processing strategies. OPTICS EXPRESS 2023; 31:26104-26119. [PMID: 37710479 DOI: 10.1364/oe.493088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Accepted: 07/05/2023] [Indexed: 09/16/2023]
Abstract
Optical aberrations are a critical issue for tight focusing and high precision manufacturing with ultrashort pulsed laser radiation in transparent media. Controlling the wave front of ultrashort laser pulses enable the correction of low order phase front distortion and significantly enhances the simplification of laser-based manufacturing of 3D-parts in glass. The influence of system-inherent, dominating aberrations such as spherical and astigmatic aberrations affect the focal area, the beam caustic and therefore the focus intensity distribution. We correct these aberrations by means of a spatial light modulator (SLM) for various processing depths in glass thickness of up to 12 mm. This flexible aberration correction significantly simplifies the process control and scanning strategies for the selective laser induced etching process. The influence on the selectivity is investigated by comparing the three different focus conditions of the intrinsic microscope objective aberration corrected, the aberrated and the SLM aberration corrected beam profile. The previously necessary pulse energy adjustment for different z positions in the glass volume is compensated via SLM aberration correction in the end. Furthermore, the spatial extend of the modified and etched area is investigated. In consequence, a simplified scan strategy and depth-independent processing parameters can be achieved for the selective laser induced etching process.
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4
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Bischoff K, Kefer S, Wienke A, Overmeyer L, Kaierle S, Esen C, Hellmann R. Integration of Bragg gratings in aerosol-jetted polymer optical waveguides for strain monitoring capabilities. OPTICS LETTERS 2023; 48:1778-1781. [PMID: 37221764 DOI: 10.1364/ol.481801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Accepted: 01/22/2023] [Indexed: 05/25/2023]
Abstract
We demonstrate and discuss the integration of Bragg gratings in aerosol-jetted polymer optical waveguides, produced in the optical assembly and connection technology for component-integrated bus systems (OPTAVER) process. By using a femtosecond laser and adaptive beam shaping, an elliptical focal voxel generates different types of single pulse modification by nonlinear absorption in the waveguide material, which are arranged periodically to form Bragg gratings. Integration of a single grating structure or, alternatively, an array of Bragg grating structures in the multimode waveguide yields a pronounced reflection signal with typical multimodal properties, i.e., a number of reflection peaks with non-Gaussian shapes. However, the main wavelength of reflection, located around 1555 nm, is evaluable by means of an appropriate smoothing algorithm. When loaded by mechanical bending, a pronounced Bragg wavelength shift of this reflected peak up to 160 pm is detected. This demonstrates that the additively manufactured waveguides can be used not only for signal transmission but also as a sensor.
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5
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Zhang H, Xu J, Li H, Xu G, Xiao Y, Cheng W, Tang X, Qin Y. Modulation of high-quality internal multifoci based on modified three-dimensional Fourier transform. OPTICS LETTERS 2023; 48:900-903. [PMID: 36790970 DOI: 10.1364/ol.479102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Accepted: 01/06/2023] [Indexed: 06/18/2023]
Abstract
We report an efficient method to generate arbitrary three-dimensional (3D) parallel multifoci inside a material. Taking into account the numerical aperture of the objective lens and the refractive index of the material, the Ewald cap was modified with a longer radius, then the whole 3D intensity distribution inside the material could be calculated using only a single Fourier transform (FT). By introducing the adaptive weight coefficient, the uniformity of the 3D multifoci improves from 81.3% to 98.9%. By adjusting the axial resolution of the Ewald cap, the uniformity of the axial multifoci improves from 85.9% to 99.7%. In the experiment, we have realized one-dimensional (1D), 2D, and 3D structures inside the fused silica, which are in excellent agreement with the simulation results. The experimental results of the "H-U-S-T" structure demonstrate that customized arbitrary intensity distribution inside the material can be realized.
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6
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Späth M, Romboy A, Nzenwata I, Rohde M, Ni D, Ackermann L, Stelzle F, Hohmann M, Klämpfl F. Experimental Validation of Shifted Position-Diffuse Reflectance Imaging (SP-DRI) on Optical Phantoms. SENSORS (BASEL, SWITZERLAND) 2022; 22:9880. [PMID: 36560250 PMCID: PMC9783365 DOI: 10.3390/s22249880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 12/07/2022] [Accepted: 12/13/2022] [Indexed: 06/17/2023]
Abstract
Numerous diseases such as hemorrhage, sepsis or cardiogenic shock induce a heterogeneous perfusion of the capillaries. To detect such alterations in the human blood flow pattern, diagnostic devices must provide an appropriately high spatial resolution. Shifted position-diffuse reflectance imaging (SP-DRI) has the potential to do so; it is an all-optical diagnostic technique. So far, SP-DRI has mainly been developed using Monte Carlo simulations. The present study is therefore validating this algorithm experimentally on realistic optical phantoms with thread structures down to 10 μm in diameter; a SP-DRI sensor prototype was developed and realized by means of additive manufacturing. SP-DRI turned out to be functional within this experimental framework. The position of the structures within the optical phantoms become clearly visible using SP-DRI, and the structure thickness is reflected as modulation in the SP-DRI signal amplitude; this performed well for a shift along the x axis as well as along the y axis. Moreover, SP-DRI successfully masked the pronounced influence of the illumination cone on the data. The algorithm showed significantly superior to a mere raw data inspection. Within the scope of the study, the constructive design of the SP-DRI sensor prototype is discussed and potential for improvement is explored.
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Affiliation(s)
- Moritz Späth
- Institute of Photonic Technologies, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91052 Erlangen, Germany
- Erlangen Graduate School in Advanced Optical Technologies, 91052 Erlangen, Germany
| | - Alexander Romboy
- Institute of Photonic Technologies, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91052 Erlangen, Germany
| | - Ijeoma Nzenwata
- Institute of Photonic Technologies, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91052 Erlangen, Germany
| | - Maximilian Rohde
- Erlangen Graduate School in Advanced Optical Technologies, 91052 Erlangen, Germany
- Department of Oral and Maxillofacial Surgery, University Hospital Erlangen, 91054 Erlangen, Germany
| | - Dongqin Ni
- Institute of Photonic Technologies, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91052 Erlangen, Germany
- Erlangen Graduate School in Advanced Optical Technologies, 91052 Erlangen, Germany
| | - Lisa Ackermann
- Institute of Photonic Technologies, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91052 Erlangen, Germany
- Erlangen Graduate School in Advanced Optical Technologies, 91052 Erlangen, Germany
| | - Florian Stelzle
- Erlangen Graduate School in Advanced Optical Technologies, 91052 Erlangen, Germany
- Department of Oral and Maxillofacial Surgery, University Hospital Erlangen, 91054 Erlangen, Germany
| | - Martin Hohmann
- Institute of Photonic Technologies, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91052 Erlangen, Germany
- Erlangen Graduate School in Advanced Optical Technologies, 91052 Erlangen, Germany
| | - Florian Klämpfl
- Institute of Photonic Technologies, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91052 Erlangen, Germany
- Erlangen Graduate School in Advanced Optical Technologies, 91052 Erlangen, Germany
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7
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Li Z, Allegre O, Li L. Realising high aspect ratio 10 nm feature size in laser materials processing in air at 800 nm wavelength in the far-field by creating a high purity longitudinal light field at focus. LIGHT, SCIENCE & APPLICATIONS 2022; 11:339. [PMID: 36456549 PMCID: PMC9715648 DOI: 10.1038/s41377-022-00962-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 07/05/2022] [Accepted: 08/18/2022] [Indexed: 06/17/2023]
Abstract
In semiconductor and data storage device manufacturing, it is desirable to produce feature sizes less than 30 nm with a high depth-to-width aspect ratio on the target material rapidly at a low cost. However, optical diffraction limits the smallest focused laser beam diameter to around half of the laser wavelength (λ/2). The existing approach to achieving nanoscale fabrication is mainly based on costly extreme ultraviolet (EUV) technology operating within the diffraction limit. In this paper, a new method is shown to achieve materials processing resolution down to 10 nm (λ/80) at an infrared laser wavelength of around 800 nm in the far-field, in air, well beyond the optical diffraction limit. A high-quality longitudinal field with a purity of 94.7% is generated to realise this super-resolution. Both experiments and theoretical modelling have been carried out to verify and understand the findings. The ablation craters induced on polished silicon, copper, and sapphire are compared for different types of light fields. Holes of 10-30 nm in diameter are produced on sapphire with a depth-to-width aspect ratio of over 16 and a zero taper with a single pulse at 100-120 nJ pulse energy. Such high aspect ratio sub-50 nm holes produced with single pulse laser irradiation are rarely seen in laser processing, indicating a new material removal mechanism with the longitudinal field. The working distance (lens to target) is around 170 µm, thus the material processing is in the far field. Tapered nano-holes can also be produced by adjusting the lens to the target distance.
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Affiliation(s)
- Zhaoqing Li
- Department of Mechanical, Aerospace and Civil Engineering, The University of Manchester, Manchester, M13 9PL, UK
| | - Olivier Allegre
- Department of Mechanical, Aerospace and Civil Engineering, The University of Manchester, Manchester, M13 9PL, UK.
| | - Lin Li
- Department of Mechanical, Aerospace and Civil Engineering, The University of Manchester, Manchester, M13 9PL, UK.
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8
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Zhang H, Xu J, Li H, Xiao Y, Cheng W, Tang X, Qin Y. Stealth dicing of 1-mm-thick glass with aberration-free axial multi-focus beams. OPTICS LETTERS 2022; 47:3003-3006. [PMID: 35709036 DOI: 10.1364/ol.460947] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Accepted: 05/18/2022] [Indexed: 06/15/2023]
Abstract
Laser stealth dicing can realize material separation with negligible surface damage, but severe aberrations in thick materials degrade processing quality. This Letter presents a nonlinear point-to-point transformation method combined with spherical aberration compensation to achieve aberration-free axial multi-focus beams. The focus peak intensity increases 7 times at a depth of 0.5 mm after spherical aberration compensation, and reaches 44 times at 3.5 mm. Spherical aberration compensation experiments showed that the width of the heat-affected zone remains almost unchanged at different depths inside the glass, and stealth dicing experiments for 1-mm-thick glass demonstrated that aberration-free 1-focus, 2-foci, and 3-foci stealth dicing can be successfully realized.
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9
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Wang M, Salter PS, Payne FP, Shipley A, Morris SM, Booth MJ, Fells JAJ. Single-mode sapphire fiber Bragg grating. OPTICS EXPRESS 2022; 30:15482-15494. [PMID: 35473267 DOI: 10.1364/oe.446664] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Accepted: 02/24/2022] [Indexed: 06/14/2023]
Abstract
Sapphire optical fiber has the ability to withstand ultrahigh temperatures and high radiation, but it is multimoded which prevents its use in many sensing applications. Problematically, Bragg gratings in such fiber exhibit multiple reflection peaks with a fluctuating power distribution. In this work, we write single-mode waveguides with Bragg gratings in sapphire using a novel multi-layer depressed cladding design in the 1550 nm telecommunications waveband. The Bragg gratings have a narrow bandwidth (<0.5 nm) and have survived annealing at 1000°C. The structures are inscribed with femtosecond laser direct writing, using adaptive beam shaping with a non-immersion objective. A single-mode sapphire fiber Bragg grating is created by writing a waveguide with a Bragg grating within a 425 µm diameter sapphire optical fiber, providing significant potential for accurate remote sensing in ultra-extreme environments.
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10
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Cui J, Antonello J, Kirkpatrick AR, Salter PS, Booth MJ. Generalised adaptive optics method for high-NA aberration-free refocusing in refractive-index-mismatched media. OPTICS EXPRESS 2022; 30:11809-11824. [PMID: 35473116 DOI: 10.1364/oe.454912] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Accepted: 03/13/2022] [Indexed: 06/14/2023]
Abstract
Phase aberrations are introduced when focusing by a high-numerical aperture (NA) objective lens into refractive-index-mismatched (RIM) media. The axial focus position in these media can be adjusted through either optical remote-focusing or mechanical stage translation. Despite the wide interest in remote-focusing, no generalised control algorithm using Zernike polynomials has been presented that performs independent remote-focusing and RIM correction in combination with mechanical stage translation. In this work, we thoroughly review derivations that model high-NA defocus and RIM aberration. We show through both numerical simulation and experimental results that optical remote-focusing using an adaptive device and mechanical stage translation are not optically equivalent processes, such that one cannot fully compensate for the other without additional aberration compensation. We further establish new orthogonal modes formulated using conventional Zernike modes and discuss its device programming to control high-NA remote-focusing and RIM correction as independent primary modes in combination with mechanical stage translation for aberration-free refocusing. Numerical simulations are performed, and control algorithms are validated experimentally by fabricating graphitic features in diamond using direct laser writing.
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11
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Butkutė A, Jonušauskas L. 3D Manufacturing of Glass Microstructures Using Femtosecond Laser. MICROMACHINES 2021; 12:499. [PMID: 33925098 PMCID: PMC8145601 DOI: 10.3390/mi12050499] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Revised: 04/11/2021] [Accepted: 04/12/2021] [Indexed: 12/20/2022]
Abstract
The rapid expansion of femtosecond (fs) laser technology brought previously unavailable capabilities to laser material processing. One of the areas which benefited the most due to these advances was the 3D processing of transparent dielectrics, namely glasses and crystals. This review is dedicated to overviewing the significant advances in the field. First, the underlying physical mechanism of material interaction with ultrashort pulses is discussed, highlighting how it can be exploited for volumetric, high-precision 3D processing. Next, three distinct transparent material modification types are introduced, fundamental differences between them are explained, possible applications are highlighted. It is shown that, due to the flexibility of fs pulse fabrication, an array of structures can be produced, starting with nanophotonic elements like integrated waveguides and photonic crystals, ending with a cm-scale microfluidic system with micro-precision integrated elements. Possible limitations to each processing regime as well as how these could be overcome are discussed. Further directions for the field development are highlighted, taking into account how it could synergize with other fs-laser-based manufacturing techniques.
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Affiliation(s)
- Agnė Butkutė
- Femtika Ltd., Saulėtekio Ave. 15, LT-10224 Vilnius, Lithuania
- Laser Research Center, Vilnius University, Saulėtekio Ave. 10, LT-10223 Vilnius, Lithuania
| | - Linas Jonušauskas
- Femtika Ltd., Saulėtekio Ave. 15, LT-10224 Vilnius, Lithuania
- Laser Research Center, Vilnius University, Saulėtekio Ave. 10, LT-10223 Vilnius, Lithuania
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12
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Yamaguchi K, Otomo K, Kozawa Y, Tsutsumi M, Inose T, Hirai K, Sato S, Nemoto T, Uji-i H. Adaptive Optical Two-Photon Microscopy for Surface-Profiled Living Biological Specimens. ACS OMEGA 2021; 6:438-447. [PMID: 33458495 PMCID: PMC7807736 DOI: 10.1021/acsomega.0c04888] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Accepted: 11/05/2020] [Indexed: 05/08/2023]
Abstract
We developed adaptive optical (AO) two-photon excitation microscopy by introducing a spatial light modulator (SLM) in a commercially available microscopy system. For correcting optical aberrations caused by refractive index (RI) interfaces at a specimen's surface, spatial phase distributions of the incident excitation laser light were calculated using 3D coordination of the RI interface with a 3D ray-tracing method. Based on the calculation, we applied a 2D phase-shift distribution to a SLM and achieved the proper point spread function. AO two-photon microscopy improved the fluorescence image contrast in optical phantom mimicking biological specimens. Furthermore, it enhanced the fluorescence intensity from tubulin-labeling dyes in living multicellular tumor spheroids and allowed successful visualization of dendritic spines in the cortical layer V of living mouse brains in the secondary motor region with a curved surface. The AO approach is useful for observing dynamic physiological activities in deep regions of various living biological specimens with curved surfaces.
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Affiliation(s)
- Kazushi Yamaguchi
- Graduate
School of Information Science and Technology, Hokkaido University, 060-0814 Sapporo, Hokkaido, Japan
- Research
Institute for Electronic Science, Hokkaido
University, 060-0814 Sapporo, Hokkaido, Japan
- Division
of Biophotonics, National Institute for Physiological Sciences, National Institutes of Natural Sciences, 444-8787 Okazaki, Aichi, Japan
| | - Kohei Otomo
- Graduate
School of Information Science and Technology, Hokkaido University, 060-0814 Sapporo, Hokkaido, Japan
- Research
Institute for Electronic Science, Hokkaido
University, 060-0814 Sapporo, Hokkaido, Japan
- Division
of Biophotonics, National Institute for Physiological Sciences, National Institutes of Natural Sciences, 444-8787 Okazaki, Aichi, Japan
- Exploratory
Research Center on Life and Living Systems, National Institutes of Natural Sciences, 444-8787 Okazaki, Aichi, Japan
- Department
of Physiological Sciences, The Graduate
School for Advanced Study, 240-0193 Hayama, Kanagawa, Japan
| | - Yuichi Kozawa
- Institute
of Multidisciplinary Research for Advanced Materials, Tohoku University, 980-8577 Sendai, Miyagi, Japan
| | - Motosuke Tsutsumi
- Research
Institute for Electronic Science, Hokkaido
University, 060-0814 Sapporo, Hokkaido, Japan
- Division
of Biophotonics, National Institute for Physiological Sciences, National Institutes of Natural Sciences, 444-8787 Okazaki, Aichi, Japan
- Exploratory
Research Center on Life and Living Systems, National Institutes of Natural Sciences, 444-8787 Okazaki, Aichi, Japan
| | - Tomoko Inose
- Graduate
School of Information Science and Technology, Hokkaido University, 060-0814 Sapporo, Hokkaido, Japan
- Research
Institute for Electronic Science, Hokkaido
University, 060-0814 Sapporo, Hokkaido, Japan
| | - Kenji Hirai
- Graduate
School of Information Science and Technology, Hokkaido University, 060-0814 Sapporo, Hokkaido, Japan
- Research
Institute for Electronic Science, Hokkaido
University, 001-0020 Sapporo, Hokkaido, Japan
| | - Shunichi Sato
- Institute
of Multidisciplinary Research for Advanced Materials, Tohoku University, 980-8577 Sendai, Miyagi, Japan
| | - Tomomi Nemoto
- Graduate
School of Information Science and Technology, Hokkaido University, 060-0814 Sapporo, Hokkaido, Japan
- Research
Institute for Electronic Science, Hokkaido
University, 060-0814 Sapporo, Hokkaido, Japan
- Division
of Biophotonics, National Institute for Physiological Sciences, National Institutes of Natural Sciences, 444-8787 Okazaki, Aichi, Japan
- Exploratory
Research Center on Life and Living Systems, National Institutes of Natural Sciences, 444-8787 Okazaki, Aichi, Japan
- Department
of Physiological Sciences, The Graduate
School for Advanced Study, 240-0193 Hayama, Kanagawa, Japan
| | - Hiroshi Uji-i
- Graduate
School of Information Science and Technology, Hokkaido University, 060-0814 Sapporo, Hokkaido, Japan
- KU
Leuven, Department of Chemistry, Celestijinenlaan 200F, 3001 Heverlee, Leuven, Belgium
- Research
Institute for Electronic Science, Hokkaido
University, 001-0020 Sapporo, Hokkaido, Japan
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13
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Deng S, Ding Z, Yuan D, Liu M, Zhou H. Investigation of the extended focusing capability of the spherical aberration to enlarge the field of view in light-sheet fluorescence microscopy. JOURNAL OF THE OPTICAL SOCIETY OF AMERICA. A, OPTICS, IMAGE SCIENCE, AND VISION 2021; 38:19-24. [PMID: 33362148 DOI: 10.1364/josaa.410209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Accepted: 11/11/2020] [Indexed: 06/12/2023]
Abstract
In light-sheet fluorescence microscopy (LSFM), using Gaussian beams for light-sheet generation results in a trade-off between the thickness and the field of view (FOV). Here we present a theoretical analysis of using spherical aberration to enlarge the FOV while keeping the light-sheet thickness small. Such spherical aberration can arise when focusing beams through an interface between materials of mismatched refractive indices. The depth-of-focus extension of the Gaussian beam is achieved when using air objectives to focus light into the samples dipped in the immersion medium with a higher refractive index. By scanning this elongated beam, a thin light sheet with a wide FOV can be used for LSFM imaging. Meanwhile, the accompanied sidelobes with the spherical aberrated light sheet, which are mainly distributed in the rear part of the light sheet, are also discussed. Simulation results show that an extended FOV of 64.4µm is possible for an objective lens of NA=0.3, which is about 5 times that of the unaberrated case. For such an extended FOV, a comparatively thin thickness of 1.38µm as well as the first sidelobe about 11.1% of the peak intensity in the center are also demonstrated.
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14
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Kontenis G, Gailevičius D, Jonušauskas L, Purlys V. Dynamic aberration correction via spatial light modulator (SLM) for femtosecond direct laser writing: towards spherical voxels. OPTICS EXPRESS 2020; 28:27850-27864. [PMID: 32988069 DOI: 10.1364/oe.397006] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Accepted: 07/13/2020] [Indexed: 06/11/2023]
Abstract
Optical aberrations are a type of optical defect of imaging systems that hinder femtosecond direct laser write machining by changing voxel size and aspect ratio in different sample depths. We present an approach of compensating such aberrations using a liquid crystal spatial light modulator (SLM). Two methods for correcting are explored. They are based on backward ray tracing and Zernike polynomials. Experiments with a long focal distance lens (F = 25 and 50 mm) and microscope objective (100x, 0.9 NA) have been conducted. Specifically, aberration-free structuring with voxels of a constant aspect ratio of 1-1.5 is carried out throughout a 1 mm thick sample. Results show potential in simplifying direct laser writing and enabling new architectures made possible by near-spherical voxels.
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15
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Menssen AJ, Guan J, Felce D, Booth MJ, Walmsley IA. Photonic Topological Mode Bound to a Vortex. PHYSICAL REVIEW LETTERS 2020; 125:117401. [PMID: 32975978 DOI: 10.1103/physrevlett.125.117401] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Accepted: 06/17/2020] [Indexed: 05/14/2023]
Abstract
We report the observation of a mode associated with a topological defect in the bulk of a 2D photonic material by introducing a vortex distortion to a hexagonal lattice analogous to graphene. The observed modes lie midgap at zero energy and are closely related to Majorana bound states in superconducting vortices. This is the first experimental demonstration of the Jackiw-Rossi model [R. Jackiw and P. Rossi, Nucl. Phys. B190, 681 (1981)NUPBBO0550-321310.1016/0550-3213(81)90044-4].
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Affiliation(s)
- Adrian J Menssen
- Department of Atomic and Laser Physics, University of Oxford, Oxford OX13PU, United Kingdom
| | - Jun Guan
- Department of Engineering Science, University of Oxford, Oxford OX13PJ, United Kingdom
| | - David Felce
- Department of Atomic and Laser Physics, University of Oxford, Oxford OX13PU, United Kingdom
| | - Martin J Booth
- Department of Engineering Science, University of Oxford, Oxford OX13PJ, United Kingdom
| | - Ian A Walmsley
- Department of Atomic and Laser Physics, University of Oxford, Oxford OX13PU, United Kingdom
- Department of Physics Imperial College, London SW72AZ, United Kingdom
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16
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Talbot L, Richter D, Heck M, Nolte S, Bernier M. Femtosecond-written volume Bragg gratings in fluoride glasses. OPTICS LETTERS 2020; 45:3625-3628. [PMID: 32630915 DOI: 10.1364/ol.396022] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Accepted: 05/27/2020] [Indexed: 06/11/2023]
Abstract
We report on what we believe are the first volume Bragg gratings written inside bulk multicomponent fluoride glasses. The gratings inscribed with tightly focused infrared (IR)-femtosecond pulses in combination with the phase-mask technique exhibit refractive index modulations of up to 5×10-4 with reflectivities up to 90% at a wavelength near 2.8 µm. Such highly compact and narrowband filters could have a significant impact on numerous high-end applications from the UV to the mid-IR.
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17
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Salter PS, Booth MJ. Adaptive optics in laser processing. LIGHT, SCIENCE & APPLICATIONS 2019; 8:110. [PMID: 31814967 PMCID: PMC6884496 DOI: 10.1038/s41377-019-0215-1] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 10/11/2019] [Accepted: 10/30/2019] [Indexed: 05/11/2023]
Abstract
Adaptive optics are becoming a valuable tool for laser processing, providing enhanced functionality and flexibility for a range of systems. Using a single adaptive element, it is possible to correct for aberrations introduced when focusing inside the workpiece, tailor the focal intensity distribution for the particular fabrication task and/or provide parallelisation to reduce processing times. This is particularly promising for applications using ultrafast lasers for three-dimensional fabrication. We review recent developments in adaptive laser processing, including methods and applications, before discussing prospects for the future.
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Affiliation(s)
- Patrick S. Salter
- Department of Engineering Science, University of Oxford, Parks Road, Oxford, OX1 3PJ UK
| | - Martin J. Booth
- Department of Engineering Science, University of Oxford, Parks Road, Oxford, OX1 3PJ UK
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18
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Lawton PF, Buckley C, Saunter CD, Wilson C, Corbett AD, Salter PS, McCarron JG, Girkin JM. Multi-plane remote refocusing epifluorescence microscopy to image dynamic Ca 2 + events. BIOMEDICAL OPTICS EXPRESS 2019; 10:5611-5624. [PMID: 31799034 PMCID: PMC6865095 DOI: 10.1364/boe.10.005611] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 09/12/2019] [Accepted: 09/12/2019] [Indexed: 05/26/2023]
Abstract
Rapid imaging of multiple focal planes without sample movement may be achieved through remote refocusing, where imaging is carried out in a plane conjugate to the sample plane. The technique is ideally suited to studying the endothelial and smooth muscle cell layers of blood vessels. These are intrinsically linked through rapid communication and must be separately imaged at a sufficiently high frame rate in order to understand this biologically crucial interaction. We have designed and implemented an epifluoresence-based remote refocussing imaging system that can image each layer at up to 20fps using different dyes and excitation light for each layer, without the requirement for optically sectioning microscopy. A novel triggering system is used to activate the appropriate laser and image acquisition at each plane of interest. Using this method, we are able to achieve axial plane separations down to 15 μ m, with a mean lateral stability of ≤ 0.32 μ m displacement using a 60x, 1.4NA imaging objective and a 60x, 0.7NA reimaging objective. The system allows us to image and quantify endothelial cell activity and smooth muscle cell activity at a high framerate with excellent lateral and good axial resolution without requiring complex beam scanning confocal microscopes, delivering a cost effective solution for imaging two planes rapidly. We have successfully imaged and analysed Ca 2 + activity of the endothelial cell layer independently of the smooth muscle layer for several minutes.
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Affiliation(s)
- Penelope F. Lawton
- Department of Physics, Durham University, South Road, Durham, DH1 3LE, UK
| | - Charlotte Buckley
- Strathclyde Institute of Pharmacy & Biomedical Sciences, University of Strathclyde, 161 Cathedral Street, Glasgow, G4 0RE, UK
| | - Chris D. Saunter
- Department of Physics, Durham University, South Road, Durham, DH1 3LE, UK
| | - Calum Wilson
- Strathclyde Institute of Pharmacy & Biomedical Sciences, University of Strathclyde, 161 Cathedral Street, Glasgow, G4 0RE, UK
| | - Alexander D. Corbett
- Department of Physics, University of Exeter, North Park Road, Exeter, EX4 4QL, UK
| | - Patrick S. Salter
- Department of Engineering Science, University of Oxford, Parks Road, Oxford OX1 3PJ, UK
| | - John G. McCarron
- Strathclyde Institute of Pharmacy & Biomedical Sciences, University of Strathclyde, 161 Cathedral Street, Glasgow, G4 0RE, UK
| | - John M. Girkin
- Department of Physics, Durham University, South Road, Durham, DH1 3LE, UK
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19
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Laser-Inscribed Stress-Induced Birefringence of Sapphire. NANOMATERIALS 2019; 9:nano9101414. [PMID: 31623407 PMCID: PMC6835502 DOI: 10.3390/nano9101414] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Revised: 09/21/2019] [Accepted: 09/26/2019] [Indexed: 11/17/2022]
Abstract
Birefringence of 3 × 10 - 3 is demonstrated inside cross-sectional regions of 100 μ m, inscribed by axially stretched Bessel-beam-like fs-laser pulses along the c-axis inside sapphire. A high birefringence and retardance of λ / 4 at mid-visible spectral range (green) can be achieved using stretched beams with axial extension of 30-40 μ m. Chosen conditions of laser-writing ensure that there are no formations of self-organized nano-gratings. This method can be adopted for creation of polarization optical elements and fabrication of spatially varying birefringent patterns for optical vortex generation.
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20
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Triplett M, Khaydarov J, Xu X, Marandi A, Imeshev G, Arntsen J, Ninan A, Miller G, Langrock C. Multi-watt, broadband second-harmonic-generation in MgO:PPSLT waveguides fabricated with femtosecond laser micromachining. OPTICS EXPRESS 2019; 27:21102-21115. [PMID: 31510193 DOI: 10.1364/oe.27.021102] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Accepted: 06/20/2019] [Indexed: 06/10/2023]
Abstract
We demonstrate optical waveguides fabricated in periodically poled MgO-doped stoichiometric lithium tantalate crystals using an fs-laser direct-write process. Two different waveguide architectures were developed: depressed cladding and stress-induced waveguides. Our strain-optic simulations confirmed the guiding mechanism for either case. We demonstrate designs optimized for low propagation loss (0.52 dB/cm) for both fundamental (1050 nm) and second-harmonic wavelengths (525 nm). Low-power CW second-harmonic-generation studies show normalized efficiencies comparable to that of annealed reverse-proton-exchange waveguides in lithium niobate. High-power studies demonstrate second-harmonic power levels up to 8.5 W in a single-pass configuration, using a 1-nm bandwidth CW IR fiber laser as a pump.
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21
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Wang X, Fells JAJ, Yip WC, Ali T, Lin JD, Welch C, Mehl GH, Booth MJ, Wilkinson TD, Morris SM, Elston SJ. Fast and low loss flexoelectro-optic liquid crystal phase modulator with a chiral nematic reflector. Sci Rep 2019; 9:7016. [PMID: 31064999 PMCID: PMC6504954 DOI: 10.1038/s41598-019-42831-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Accepted: 04/05/2019] [Indexed: 11/09/2022] Open
Abstract
In this paper, we demonstrate a flexoelectro-optic liquid crystal phase-only device that uses a chiral nematic reflector to achieve full 2π phase modulation. This configuration is found to be very tolerant to imperfections in the chiral nematic reflector provided that the flexoelectro-optic LC layer fulfils the half-wave condition. Encouragingly, the modulation in the phase, which operates at kHz frame rates, is also accompanied by low amplitude modulation. The configuration demonstrated herein is particularly promising for the development of next-generation liquid crystal on silicon spatial light modulators.
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Affiliation(s)
- Xiuze Wang
- Department of Engineering Science, University of Oxford, Parks Road, Oxford, OX1 3PJ, UK
| | - Julian A J Fells
- Department of Engineering Science, University of Oxford, Parks Road, Oxford, OX1 3PJ, UK
| | - Wing C Yip
- Department of Engineering, University of Cambridge, Cambridge, CB3 0FA, UK
| | - Taimoor Ali
- Department of Engineering Science, University of Oxford, Parks Road, Oxford, OX1 3PJ, UK
| | - Jia-de Lin
- Department of Engineering Science, University of Oxford, Parks Road, Oxford, OX1 3PJ, UK
| | - Chris Welch
- Department of Chemistry, University of Hull, Hull, HU6 7RX, UK
| | - Georg H Mehl
- Department of Chemistry, University of Hull, Hull, HU6 7RX, UK
| | - Martin J Booth
- Department of Engineering Science, University of Oxford, Parks Road, Oxford, OX1 3PJ, UK
| | | | - Stephen M Morris
- Department of Engineering Science, University of Oxford, Parks Road, Oxford, OX1 3PJ, UK.
| | - Steve J Elston
- Department of Engineering Science, University of Oxford, Parks Road, Oxford, OX1 3PJ, UK.
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22
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Corbett AD, Shaw M, Yacoot A, Jefferson A, Schermelleh L, Wilson T, Booth M, Salter PS. Microscope calibration using laser written fluorescence. OPTICS EXPRESS 2018; 26:21887-21899. [PMID: 30130891 PMCID: PMC6238825 DOI: 10.1364/oe.26.021887] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Revised: 07/27/2018] [Accepted: 08/01/2018] [Indexed: 05/26/2023]
Abstract
There is currently no widely adopted standard for the optical characterization of fluorescence microscopes. We used laser written fluorescence to generate two- and three-dimensional patterns to deliver a quick and quantitative measure of imaging performance. We report on the use of two laser written patterns to measure the lateral resolution, illumination uniformity, lens distortion and color plane alignment using confocal and structured illumination fluorescence microscopes.
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Affiliation(s)
| | - Michael Shaw
- National Physical Laboratory, Hampton Rd, Teddington TW11 0LW, UK
- Department of Computer Science, University College London, London WC1 6BT, UK
| | - Andrew Yacoot
- National Physical Laboratory, Hampton Rd, Teddington TW11 0LW, UK
| | - Andrew Jefferson
- Micron Oxford Advanced Bioimaging Unit, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Lothar Schermelleh
- Micron Oxford Advanced Bioimaging Unit, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Tony Wilson
- Department of Engineering Science, University of Oxford, Parks Road, Oxford OX1 3PJ, UK
| | - Martin Booth
- Department of Engineering Science, University of Oxford, Parks Road, Oxford OX1 3PJ, UK
| | - Patrick S. Salter
- Department of Engineering Science, University of Oxford, Parks Road, Oxford OX1 3PJ, UK
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23
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Lapointe J, Kashyap R. A simple technique to overcome self-focusing, filamentation, supercontinuum generation, aberrations, depth dependence and waveguide interface roughness using fs laser processing. Sci Rep 2017; 7:499. [PMID: 28356554 PMCID: PMC5428688 DOI: 10.1038/s41598-017-00589-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Accepted: 03/03/2017] [Indexed: 11/08/2022] Open
Abstract
Several detrimental effects limit the use of ultrafast lasers in multi-photon processing and the direct manufacture of integrated photonics devices, not least, dispersion, aberrations, depth dependence, undesirable ablation at a surface, limited depth of writing, nonlinear optical effects such as supercontinuum generation and filamentation due to Kerr self-focusing. We show that all these effects can be significantly reduced if not eliminated using two coherent, ultrafast laser-beams through a single lens - which we call the Dual-Beam technique. Simulations and experimental measurements at the focus are used to understand how the Dual-Beam technique can mitigate these problems. The high peak laser intensity is only formed at the aberration-free tightly localised focal spot, simultaneously, suppressing unwanted nonlinear side effects for any intensity or processing depth. Therefore, we believe this simple and innovative technique makes the fs laser capable of much more at even higher intensities than previously possible, allowing applications in multi-photon processing, bio-medical imaging, laser surgery of cells, tissue and in ophthalmology, along with laser writing of waveguides.
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Affiliation(s)
- Jerome Lapointe
- FABULAS, Department of Engineering Physics, Polytechnique Montreal, 2900 Edouard-Montpetit, Montreal H3T 1J4, Canada.
- Poly-Grames Research Center, 2500 Chemin Polytechnique, Montreal H3T 1J4, Canada.
| | - Raman Kashyap
- FABULAS, Department of Engineering Physics, Polytechnique Montreal, 2900 Edouard-Montpetit, Montreal H3T 1J4, Canada
- Department of Electrical Engineering, Polytechnique Montreal, 2900 Edouard-Montpetit, Montreal H3T 1J4, Canada
- Poly-Grames Research Center, 2500 Chemin Polytechnique, Montreal H3T 1J4, Canada
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24
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Matsumoto N, Konno A, Ohbayashi Y, Inoue T, Matsumoto A, Uchimura K, Kadomatsu K, Okazaki S. Correction of spherical aberration in multi-focal multiphoton microscopy with spatial light modulator. OPTICS EXPRESS 2017; 25:7055-7068. [PMID: 28381046 DOI: 10.1364/oe.25.007055] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
We demonstrate that high-quality images of the deep regions of a thick sample can be obtained from its surface by multi-focal multiphoton microscopy (MMM). The MMM system incorporates a spatial light modulator to separate the excitation beam into a multi-focal excitation beam and modulate the pre-distortion wavefront to correct spherical aberration (SA) caused by a refractive index mismatch between the immersion medium and the biological sample. When fluorescent beads in transparent epoxy resin were observed using four SA-corrected focal beams, the fluorescence signal of the obtained images was ~52 times higher than that obtained without SA correction until a depth of ~1100 μm, similar to the result for single-focal multiphoton microscopy (SMM). The MMM scanning time was four times less than that for SMM, and MMM showed an improved fluorescence intensity and depth resolution for an image of blood vessels in the brain of a mouse stained with a fluorescent dye.
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25
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Bérubé JP, Vallée R. Femtosecond laser direct inscription of surface skimming waveguides in bulk glass. OPTICS LETTERS 2016; 41:3074-3077. [PMID: 27367105 DOI: 10.1364/ol.41.003074] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We present a detailed study of waveguide inscription near the surface of bulk glass using a femtosecond laser. Three silicate glasses used extensively as hosts for photo-induced photonic devices were examined. Our results show that near-surface waveguides generally present a low-index contrast, as the pulse energy damage threshold decreases sharply at close proximity to the surface. We devised a novel method to allow the formation of optical waveguides that exhibit a high-index contrast up to the surface of any transparent material. As a proof of concept, the inscription of near-surface single-mode waveguides operating at a wavelength of 405 nm is demonstrated.
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26
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Matsumoto N, Inoue T, Matsumoto A, Okazaki S. Correction of depth-induced spherical aberration for deep observation using two-photon excitation fluorescence microscopy with spatial light modulator. BIOMEDICAL OPTICS EXPRESS 2015; 6:2575-2587. [PMID: 26203383 PMCID: PMC4505711 DOI: 10.1364/boe.6.002575] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2015] [Revised: 06/11/2015] [Accepted: 06/12/2015] [Indexed: 05/29/2023]
Abstract
We demonstrate fluorescence imaging with high fluorescence intensity and depth resolution in which depth-induced spherical aberration (SA) caused by refractive-index mismatch between the medium and biological sample is corrected. To reduce the impact of SA, we incorporate a spatial light modulator into a two-photon excitation fluorescence microscope. Consequently, when fluorescent beads in epoxy resin were observed with this method of SA correction, the fluorescence signal of the observed images was ∼27 times higher and extension in the direction of the optical axes was ∼6.5 times shorter at a depth of ∼890 μm. Thus, the proposed method increases the depth observable at high resolution. Further, our results show that the method improved the fluorescence intensity of images of the fluorescent beads and the structure of a biological sample.
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Affiliation(s)
- Naoya Matsumoto
- Central Research Laboratory, Hamamatsu Photonics K.K., 5000 Hirakuchi, Hamakita-ku, Hamamatsu-City, Shizuoka-Pref., 434-8601,
Japan
| | - Takashi Inoue
- Central Research Laboratory, Hamamatsu Photonics K.K., 5000 Hirakuchi, Hamakita-ku, Hamamatsu-City, Shizuoka-Pref., 434-8601,
Japan
| | - Akiyuki Matsumoto
- Department of Biochemistry, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya-City, Aichi-Pref., 466-8550,
Japan
| | - Shigetoshi Okazaki
- Department of Medical Spectroscopy, Applied Medical Photonics
Laboratory, Medical Photonics Research Center, Hamamatsu University School of
Medicine, 1-20-1 Handayama, Higashi-ku, Hamamatsu-City, Shizuoka-Pref.,
431-3192, Japan
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27
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Corbett AD, Burton RAB, Bub G, Salter PS, Tuohy S, Booth MJ, Wilson T. Quantifying distortions in two-photon remote focussing microscope images using a volumetric calibration specimen. Front Physiol 2014; 5:384. [PMID: 25339910 PMCID: PMC4189333 DOI: 10.3389/fphys.2014.00384] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Accepted: 09/18/2014] [Indexed: 02/03/2023] Open
Abstract
Remote focussing microscopy allows sharp, in-focus images to be acquired at high speed from outside of the focal plane of an objective lens without any agitation of the specimen. However, without careful optical alignment, the advantages of remote focussing microscopy could be compromised by the introduction of depth-dependent scaling artifacts. To achieve an ideal alignment in a point-scanning remote focussing microscope, the lateral (XY) scan mirror pair must be imaged onto the back focal plane of both the reference and imaging objectives, in a telecentric arrangement. However, for many commercial objective lenses, it can be difficult to accurately locate the position of the back focal plane. This paper investigates the impact of this limitation on the fidelity of three-dimensional data sets of living cardiac tissue, specifically the introduction of distortions. These distortions limit the accuracy of sarcomere measurements taken directly from raw volumetric data. The origin of the distortion is first identified through simulation of a remote focussing microscope. Using a novel three-dimensional calibration specimen it was then possible to quantify experimentally the size of the distortion as a function of objective misalignment. Finally, by first approximating and then compensating the distortion in imaging data from whole heart rodent studies, the variance of sarcomere length (SL) measurements was reduced by almost 50%.
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Affiliation(s)
- Alexander D Corbett
- Department of Engineering Science, University of Oxford Oxford, UK ; Department of Physiology, Anatomy and Genetics, University of Oxford Oxford, UK
| | - Rebecca A B Burton
- Department of Physiology, Anatomy and Genetics, University of Oxford Oxford, UK
| | - Gil Bub
- Department of Physiology, Anatomy and Genetics, University of Oxford Oxford, UK
| | - Patrick S Salter
- Department of Engineering Science, University of Oxford Oxford, UK
| | - Simon Tuohy
- Department of Physiology, Anatomy and Genetics, University of Oxford Oxford, UK
| | - Martin J Booth
- Department of Engineering Science, University of Oxford Oxford, UK ; Department of Physiology, Anatomy and Genetics, University of Oxford Oxford, UK
| | - Tony Wilson
- Department of Engineering Science, University of Oxford Oxford, UK
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