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Guo F, Yu P, Gao Z, Wang Z, Tao X. Spontaneous Raman spectra analysis and efficient nanosecond pulse Raman laser of a BaTeW 2O 9 crystal. OPTICS LETTERS 2022; 47:4624-4627. [PMID: 36107048 DOI: 10.1364/ol.470067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Accepted: 08/16/2022] [Indexed: 06/15/2023]
Abstract
In this Letter, the spontaneous Raman spectra of a novel, to the best of our knowledge, crystal α-BaTeW2O9 (α-BTW) are characterized and analyzed. The relative Raman gain coefficient of the α-BTW crystal is calculated to be 0.84 times that of YVO4. With a 35-mm-long crystal, the first-order Raman laser of α-BTW operating at 1178 nm is realized. The simple external resonator setup is employed in the first-order Raman laser of α-BTW. The pump source is a lamp-pumped electric-optical Q switched Nd:YAG laser amplifier system operating at 1064 nm with a pulse width of 10 ns. The Raman laser exhibits a threshold of 14.7 MW/cm2. In our experiments, a maximum pulse energy of 21.5 mJ is obtained with an optical-to-optical conversion efficiency and slope efficiency of 43.6%, 57.9%, respectively. Due to its high laser damage threshold, relative high Raman gain coefficient, and excellent thermal properties, the α-BTW crystal is a potential Raman material.
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Lai CC, Lo CY, Hsieh TH, Tsai WS, Nguyen DH, Ma YR. Ligand-Driven and Full-Color-Tunable Fiber Source: Toward Next-Generation Clinic Fiber-Endoscope Tomography with Cellular Resolution. ACS OMEGA 2016; 1:552-565. [PMID: 31457146 PMCID: PMC6640774 DOI: 10.1021/acsomega.6b00146] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Accepted: 10/03/2016] [Indexed: 06/10/2023]
Abstract
In many biomedical applications, broad full-color emission is important, especially for wavelengths below 450 nm, which are difficult to cover via supercontinuum generation. Single-crystalline-core sapphires with defect-driven emissions have potential roles in the development of next-generation broadband light sources because their defect centers demonstrate multiple emission bands with tailored ligand fields. However, the inability to realize high quantum yields with high crystallinity by conventional methods hinders the applicability of ultra-broadband emissions. Here, we present how an effective one-step fiber-drawing process, followed by a simple and controllable thermal treatment, enables a low-loss, full-color, and crystal fiber-based generation with substantial color variability. The broad spectrum extends from 330 nm, which is over 50 nm further into the UV region than that in previously reported results. The predicted submicrometer spatial resolutions demonstrate that the defect-ligand fields are potentially beneficial for achieving in vivo cellular tomography. It is also noteworthy that the efficiency of the milliwatt-level full-color generation, with an optical-to-optical efficiency of nearly 5%, is the highest among that of the existing active waveguide schemes. In addition, direct evidence from high-resolution transmission electron microscopy together with electron energy loss spectroscopy and crystal-field ligands reveals an excellent crystalline core, atomically defined core/cladding interfacial roughness, and significant enhancements in new laser-induced electronic defect levels. Our work suggests an inexpensive, facile, and highly scalable route toward achieving cellular-resolution tomographic imaging and represents an important step in the development of endoscope-compatible diagnostic devices.
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Affiliation(s)
- Chien-Chih Lai
- Department of Physics and Department of Opto-Electronic Engineering, National Dong Hwa University, No. 1, Sec. 2, Da Hsueh Road,
Shoufeng, Hualien 97401, Taiwan
| | - Chia-Yao Lo
- Institute
of Optoelectronic Sciences, National Taiwan
Ocean University, No.
2, Beining Road, Jhongjheng District, Keelung 20224, Taiwan
| | - Tsung-Hsun Hsieh
- Department
of Electrical and Computer Engineering, North Carolina State University, 890 Oval Drive, Raleigh, North Carolina 27606, United States
| | - Wan-Shao Tsai
- Department
of Applied Materials and Optoelectronics Engineering, National Chi Nan University, Daxue Road, Puli Township, Nantou 54561, Taiwan
| | - Duc Huy Nguyen
- Department of Physics and Department of Opto-Electronic Engineering, National Dong Hwa University, No. 1, Sec. 2, Da Hsueh Road,
Shoufeng, Hualien 97401, Taiwan
| | - Yuan-Ron Ma
- Department of Physics and Department of Opto-Electronic Engineering, National Dong Hwa University, No. 1, Sec. 2, Da Hsueh Road,
Shoufeng, Hualien 97401, Taiwan
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Nie W, He R, Cheng C, Rocha U, Rodríguez Vázquez de Aldana J, Jaque D, Chen F. Optical lattice-like cladding waveguides by direct laser writing: fabrication, luminescence, and lasing. OPTICS LETTERS 2016; 41:2169-2172. [PMID: 27176954 DOI: 10.1364/ol.41.002169] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We report on the fabrication of optical lattice-like waveguide structures in an Nd:YAP laser crystal by using direct femtosecond laser writing. With periodically arrayed laser-induced tracks, the waveguiding cores can be located in either the regions between the neighbored tracks or the central zone surrounded by a number of tracks as outer cladding. The polarization of the femtosecond laser pulses for the inscription has been found to play a critical role in the anisotropic guiding behaviors of the structures. The confocal photoluminescence investigations reveal different stress-induced modifications of the structures inscribed by different polarization of the femtosecond laser beam, which are considered to be responsible for the refractive index changes of the structures. Under optical pump at 808 nm, efficient waveguide lasing at ∼1 μm wavelength has been realized from the optical lattice-like structure, which exhibits potential applications as novel miniature light sources.
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Nie W, Cheng C, Jia Y, Romero C, Vázquez de Aldana JR, Chen F. Dual-wavelength waveguide lasers at 1064 and 1079 nm in Nd:YAP crystal by direct femtosecond laser writing. OPTICS LETTERS 2015; 40:2437-2440. [PMID: 26393759 DOI: 10.1364/ol.40.002437] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Low-loss depressed cladding waveguides have been produced in Nd:YAP laser crystal by using direct femtosecond laser writing. Under optical pump at 812 nm at room temperature, continuous-wave simultaneous dual-wavelength laser oscillations at 1064 and 1079 nm, both along TM polarization, have been realized in the waveguiding structures. It has been found that, with the variation of pump polarization, the intensity ratio of 1064 and 1079 nm emissions varies periodically, while the polarization of output dual-wavelength laser remains unchanged. The maximum output power achieved for the Nd:YAP waveguide lasers is ∼200 mW with a slope efficiency of 33.4%.
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Pavel N, Salamu G, Jipa F, Zamfirescu M. Diode-laser pumping into the emitting level for efficient lasing of depressed cladding waveguides realized in Nd:YVO4 by the direct femtosecond-laser writing technique. OPTICS EXPRESS 2014; 22:23057-23065. [PMID: 25321776 DOI: 10.1364/oe.22.023057] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Depressed cladding waveguides have been realized in Nd:YVO(4) employing direct writing technique with a femtosecond-laser beam. It was shown that the output performances of such laser devices are improved by the reduction of the quantum defect between the pump wavelength and the laser wavelength. Thus, under the classical pump at 808 nm (i.e. into the (4)F(5/2) level), a 100-μm diameter circular waveguide inscribed in a 0.7-at.% Nd:YVO(4) outputted 1.06-μm laser pulses with 3.0-mJ energy, at 0.30 optical efficiency and slope efficiency of 0.32. The pump at 880 nm (i.e.directly into the (4)F(3/2) emitting level) increased the pulse energy at 3.8 mJ and improved both optical efficiency and slope efficiency at 0.36 and 0.39, respectively. The same waveguide yielded continuous-wave 1.5-W output power at 1.06 μm under the pump at 880 nm. Laser emission at 1.34 μm was also improved using the pump into the (4)F(3/2) emitting level of Nd:YVO(4).
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Long X, Bai J, Zhao W, Stoian R, Hui R, Cheng G. Stressed waveguides with tubular depressed-cladding inscribed in phosphate glasses by femtosecond hollow laser beams. OPTICS LETTERS 2012; 37:3138-3140. [PMID: 22859111 DOI: 10.1364/ol.37.003138] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We report on the single-step fabrication of stressed optical waveguides with tubular depressed-refractive-index cladding in phosphate glasses by the use of focused femtosecond hollow laser beams. Tubelike low index regions appear under direct exposure due to material rarefaction following expansion. Strained compacted zones emerged in domains neighboring the tubular track of lower refractive index, and waveguiding occurs mainly within the tube core fabricated by the engineered femtosecond laser beam. The refractive index profile of the optical waveguide was reconstructed from the measured transmitted near-field intensity.
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Affiliation(s)
- Xuewen Long
- State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an 710119, China
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Li SL, Han P, Shi M, Yao Y, Hu B, Wang M, Zhu X. Low-loss channel optical waveguide fabrication in Nd(3+)-doped silicate glasses by femtosecond laser direct writing. OPTICS EXPRESS 2011; 19:23958-23964. [PMID: 22109420 DOI: 10.1364/oe.19.023958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Optical waveguides were fabricated in neodymium-doped silicate glass by using a low-repetition-rate (1 kHz) femtosecond laser inscription. Two different types of waveguide structure are fabricated. In the first, guiding occurs in the focal spot. In the second, guiding occurs in the region between the two filaments. The near-field intensity distribution, propagation loss, index profile reconstruction, and calculation of the modal intensity distribution by the beam propagation method of these waveguides are presented. On the basis of near-field intensity distribution of the light guided through the waveguides and the propagation loss measurement, the optimum writing conditions such as the pulse energy and scan velocity were determined. The waveguide written with 2.2 µJ pulse energy and 50 µm/s scan velocity shows strong guidance at 632.8 nm, with an index contrast of 7 × 10(-4) and a propagation loss of ~0.8 dB/cm.
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Affiliation(s)
- Shi-Ling Li
- College of Physics and Engineering, Shandong Provincial Key Laboratory of Laser and Information Technology, Qufu Normal University, Qufu 273165, China.
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Yao Y, Dong N, Chen F, Pang L, Wang Z, Lu Q. Continuous wave waveguide lasers of swift argon ion irradiated Nd:YVO4 waveguides. OPTICS EXPRESS 2011; 19:24252-24257. [PMID: 22109451 DOI: 10.1364/oe.19.024252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We report on the fabrication of planar waveguide in Nd:YVO(4) crystal by using swift Ar(8+) ion irradiation. At room temperature continuous wave (cw) laser oscillation at wavelength of ~1067 nm has been realized through the optical pump at 808 nm with a low threshold of 9.3 mW. The slope efficiency of the waveguide laser system is of 8.5%. The optical-to-optical conversion efficiency is 6.6%.
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Affiliation(s)
- Yicun Yao
- School of Physics, Key Laboratory of Particle Physics and Particle Irradiation (MOE) and State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China
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Rodenas A, Kar AK. High-contrast step-index waveguides in borate nonlinear laser crystals by 3D laser writing. OPTICS EXPRESS 2011; 19:17820-33. [PMID: 21935150 DOI: 10.1364/oe.19.017820] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
We report the ultrafast fabrication of high-contrast step-index channel waveguides in Nd(3+):YCa(4)O(BO(3))(3) borate laser crystals by means of 3D direct laser writing. Guiding up to 3.4 μm wavelength is demonstrated for the first time in a laser written crystalline waveguide. Modeling the measured fundamental modes at the wavelengths of 1.9 µm and 3.4 µm allowed us to estimate the high laser-induced refractive index increments (index contrasts) to be 0.010 (0.59%), and 0.005 (0.29%), respectively. Confocal µ-Raman spectral imaging of the waveguides cross-sections confirmed that the cores have very well defined step profiles, and that the increase in the refractive index can be linked to the localized creation of permanent intrinsic defects. These results indicate that this crystalline waveguides are a potential candidate for the development of 3D active waveguide circuits, due to the laser and electro-optic properties of rare earth doped borate crystals.
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Affiliation(s)
- Airan Rodenas
- School of Engineering and Physical Sciences, Physics Department, Heriot-Watt University, Edinburgh, Scotland, UK.
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Dong N, Tan Y, Benayas A, de Aldana JV, Jaque D, Romero C, Chen F, Lu Q. Femtosecond laser writing of multifunctional optical waveguides in a Nd:YVO4 + KTP hybrid system. OPTICS LETTERS 2011; 36:975-977. [PMID: 21403747 DOI: 10.1364/ol.36.000975] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We report on the fabrication of optical channel waveguides supporting both visible and IR TE and TM confinement in a hybrid system composed of a Nd:YVO4 laser gain medium glued to a potassium titanyl phosphate (KTP) nonlinear crystal. The microphotoluminescence and second harmonic confocal images of the fabricated waveguides have revealed that the laser and nonlinear properties of the constituent crystals have not been deteriorated because of the waveguide inscription. The resulting structures emerge as promising candidates for the development of multifrequency waveguide lasers.
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Affiliation(s)
- Ningning Dong
- School of Physics, Shandong University, Jinan, China
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Liu X, Qu S, Tan Y, Chen F. Preservation of fluorescence and Raman gain in the buried channel waveguides in neodymium-doped KGd(WO4)2(Nd:KGW) by femtosecond laser writing. APPLIED OPTICS 2011; 50:930-934. [PMID: 21343973 DOI: 10.1364/ao.50.000930] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We report on the preservation of fluorescence and Raman gain in low-repetition-rate femtosecond laser written buried channel waveguides in neodymium-doped KGd(WO4)2. The propagation loss index, profile reconstruction, and calculation of the modal intensity distribution by the beam propagation method of the waveguide are presented. Microluminescence spectra of the waveguides show that the fluorescence properties of Nd3+ ions are not significantly affected by the waveguide formation processing, which indicates a fairly good potential for further laser actions in a compact device. Micro-Raman spectra are also performed to reveal the preservation of the characteristic 768 and 901 cm-1 Raman mode intensities in the guiding regions.
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Affiliation(s)
- Xiaoyu Liu
- Department of Physics, Harbin Institute of Technology, Harbin 150001, China
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Siebenmorgen J, Calmano T, Petermann K, Huber G. Highly efficient Yb:YAG channel waveguide laser written with a femtosecond-laser. OPTICS EXPRESS 2010; 18:16035-16041. [PMID: 20720988 DOI: 10.1364/oe.18.016035] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Using a femtosecond Ti:Sapphire laser, micro-tracks of material damage were written into Yb:YAG crystals. Waveguiding was achieved in a channel between pairs of tracks with guiding losses of 1.3 dB/cm at a wavelength of 1063 nm, due to a stress induced change of the refractive index. Pumped at a wavelength of 941 nm, highly efficient laser oscillation in a Yb:YAG channel waveguide at a wavelength of 1030 nm was demonstrated. An output power of 0.8 W at 1.2 W of launched pump power was achieved, resulting in a record slope efficiency of 75%.
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Affiliation(s)
- Jörg Siebenmorgen
- Universität Hamburg, Institut für Laser-Physik, Luruper Chaussee 149, 22761 Hamburg, Germany.
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