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Wang H, Cha S, Kong HJ, Wang Y, Lu Z. Sub-nanosecond stimulated Brillouin scattering pulse compression using HT270 for kHz repetition rate operation. OPTICS EXPRESS 2019; 27:29789-29802. [PMID: 31684236 DOI: 10.1364/oe.27.029789] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 08/30/2019] [Indexed: 06/10/2023]
Abstract
With mitigation of thermal effects in a generator cell based on a rotating off-centered lens, the effects of thermal blooming, self-defocusing, and thermal convection in the amplifier cell have experimentally proven to be the main factors limiting high-repetition-rate stimulated Brillouin scattering (SBS) pulse compression. To alleviate these effects, Galden HT270, which has a large viscosity coefficient, is used and compared experimentally. The operating repetition rate using HT270 was improved from 200 Hz to 1,000 Hz, comparable to the values in the literature. With a pump energy of 50 mJ at 1,000 Hz, the pump pulse was compressed down to 820 ps using HT270 with an energy efficiency of 52.2%. If the injection energy is further increased, the SBS energy efficiency can be increased beyond this value.
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Wang H, Cha S, Kong HJ, Wang Y, Lu Z. Rotating off-centered lens in SBS phase conjugation mirror for high-repetition-rate operation. OPTICS EXPRESS 2019; 27:9895-9905. [PMID: 31045137 DOI: 10.1364/oe.27.009895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Accepted: 03/15/2019] [Indexed: 06/09/2023]
Abstract
A new method using a rotating off-centered lens is proposed to reduce the heat accumulation at the focal spot of a stimulated Brillouin scattering phase conjugation mirror at high-repetition-rate operation. Theoretical simulation of the beam intensity pattern at the focal point indicates there is less coma-aberration using a rotating off-centered focusing lens than with a rotating wedge and a conventional lens. The resultant SBS output parameters using this new method are substantially improved comparable to those of a non-rotating conventional method for high-repetition-rate operation, while the former operates quite well for higher power and the latter operates only for lower input power. High reflected energy and a good beam pattern are demonstrated using the proposed method in the present experimental conditions of 50 mJ at 1 kHz.
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Wang H, Cha S, Kong HJ, Wang Y, Lu Z. Minimizing cross sectional pulse width difference between central and edge parts of SBS compressed beam. OPTICS EXPRESS 2019; 27:1646-1659. [PMID: 30696227 DOI: 10.1364/oe.27.001646] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Accepted: 12/19/2018] [Indexed: 06/09/2023]
Abstract
For minimizing the spatial cross-sectional pulse width difference in the reflected SBS compressed beam, two new methods, blocking beam edge and parameter optimization, are proposed and compared experimentally. Results show that the sub-nanosecond compressed pulse width at the beam edge can be obtained by using both two methods in this paper. The pulse width difference between the beam center and the edge is minimized through selecting a proper medium and the optimized structural parameters in a single-cell SBS compressor. Its energy efficiency reaches up to 81.5% by using the medium HT110 and is two times higher than that of the blocking beam edge method. The compressed pulse width's stability improved greatly by using these two methods.
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Yuan H, Wang Y, Lu Z, Zheng Z. Active frequency matching in stimulated Brillouin amplification for production of a 2.4 J, 200 ps laser pulse. OPTICS LETTERS 2018; 43:511-514. [PMID: 29400828 DOI: 10.1364/ol.43.000511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Accepted: 12/29/2017] [Indexed: 06/07/2023]
Abstract
A frequency matching Brillouin amplification in high-power solid-state laser systems is proposed. The energy extraction efficiency could be maintained at a high level in a non-collinear Brillouin amplification structure using an exact Stokes frequency shift. Laser pulses having a width of 200 ps and energy of 2.4 J were produced. This method can be used to transfer energy from a long pulse to a short pulse through a high-power solid-state laser system.
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Yuan H, Wang Y, Lu Z, Wang Y, Liu Z, Bai Z, Cui C, Liu R, Zhang H, Hasi W. Fluctuation initiation of Stokes signal and its effect on stimulated Brillouin scattering pulse compression. OPTICS EXPRESS 2017; 25:14378-14388. [PMID: 28789024 DOI: 10.1364/oe.25.014378] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Accepted: 05/26/2017] [Indexed: 06/07/2023]
Abstract
In this paper, a theoretical model is developed to demonstrate that fluctuations in the Stokes signal and occurrence position contribute to the final compression ratio in stimulated Brillouin scattering (SBS). This theoretical analysis can be applied to the investigation of the temporal characteristics of SBS pulse compression. This model agrees well with the experimental results in a two-stage SBS compressor.
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Feng C, Xu X, Diels JC. Spatio-temporal characterization of pulses obtained from a high-energy sub-nanosecond laser system. APPLIED OPTICS 2016; 55:1603-1612. [PMID: 26974618 DOI: 10.1364/ao.55.001603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Spatio-temporal profiles of laser pulses, obtained from each stage of a high-energy sub-nanosecond laser system, are investigated. The laser system is composed of a Q-switched Nd:YAG unstable oscillator, a chain of Nd:YAG amplifiers, a second-harmonic generator, and a high-energy pulse compressor based on stimulated Brillouin scattering (SBS). A curved energy front, i.e., the pulses emerging away from the beam center being gradually delayed from the center pulse, is shown to originate from the unstable oscillator. Our comparative study shows that injection seeding will enlarge the energy front curvature, via reduction of the effective gain. After the laser amplifiers, the energy front curvature is more than doubled due to the gain saturation effect. The latter also modifies the spatial pulse width distribution. While there is a negligible pulse duration spread across the oscillator beam, the amplified pulses are found to have gradually reduced pulse duration away from the beam center. More interestingly, after the SBS pulse compression, not only the pulse width but also the delay is compressed down. This is, to the best of our knowledge, the first study of the spatio-temporal profile of the SBS compressed pulse. To compare with the experiments, two numerical models are developed to simulate the evolution of spatio-temporal profiles within the Nd:YAG laser system and during the SBS pulse compression, respectively. The first model is demonstrated to reproduce the experimental results very well, while the second model predicts part of the features of the SBS compressed pulse. The limitation on the latter is discussed.
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Feng C, Diels JC, Xu X, Arissian L. Ring-shaped backward stimulated Raman scattering driven by stimulated Brillouin scattering. OPTICS EXPRESS 2015; 23:17035-17045. [PMID: 26191712 DOI: 10.1364/oe.23.017035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Backward stimulated Raman scattering is generated in water, pumped by pre-compressed pulses from a single-cell stimulated Brillouin scattering pulse compressor. The maximum energy efficiency of 9% is achieved by employing a circularly-polarized pump pulse at its energy of 50 mJ, around which point the backward stimulated Raman scattering also exhibits a ring-shaped profile. The correlations between spatial and temporal profiles as well as the intensities of the backward stimulated Raman and the stimulated Brillouin scattering generated from Raman cell indicate that the ring-shaped backward stimulated Raman is driven by intense stimulated Brillouin scattering. We demonstrate the latter process to be much more efficient for the backward Raman generation than the conventional process in which the laser itself pumps a backward stimulated Raman beam. It is shown that a further increase in pump energy leads to a drop in efficiency, combined with a break-up of the ring pattern of backward stimulated Raman. These effects are associated with filament generation above a certain threshold.
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Feng C, Xu X, Diels JC. Generation of 300 ps laser pulse with 1.2 J energy by stimulated Brillouin scattering in water at 532 nm. OPTICS LETTERS 2014; 39:3367-3370. [PMID: 24978487 DOI: 10.1364/ol.39.003367] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We demonstrate high-energy pulse compression by stimulated Brillouin scattering (SBS) in water using an energy-scalable generator amplifier setup. Pulse compression from 2.4 J, 12 ns at 532 nm to 1.2 J, 300 ps has been achieved, which to our knowledge represents the highest compressed energy achieved at 532 nm using SBS and is only limited by the size of our optics. Our setup is robust and stable over long periods of operation (2% of energy fluctuation and <3% shot-to-shot variation of pulse width).
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Xu X, Feng C, Diels JC. Optimizing sub-ns pulse compression for high energy application. OPTICS EXPRESS 2014; 22:13904-13915. [PMID: 24921582 DOI: 10.1364/oe.22.013904] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We demonstrate ∼ 40X pulse compression (down to ∼ 300 ps) with ∼ 1 joule, nanosecond pulses for high energy applications requiring ≥ 1 gigawatt of peak power. Our method is based on the established principle of stimulated Brillouin scattering (SBS). To push the SBS technique to its highest peak-power limit, a combination of theoretical modeling and experiments is used to identify and optimize all critical parameters, including optical configuration, interaction length, intensity matching, choice of gain medium and thermal stability. Pulse compression results are presented both at 1064 nm and 532 nm, with performances close to the theoretical limit and excellent shot-to-shot reproducibility.
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Büttner TFS, Kabakova IV, Hudson DD, Pant R, Poulton CG, Judge AC, Eggleton BJ. Phase-locking and pulse generation in multi-frequency brillouin oscillator via four wave mixing. Sci Rep 2014; 4:5032. [PMID: 24849053 PMCID: PMC4030313 DOI: 10.1038/srep05032] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Accepted: 05/02/2014] [Indexed: 11/09/2022] Open
Abstract
There is an increasing demand for pulsed all-fibre lasers with gigahertz repetition rates for applications in telecommunications and metrology. The repetition rate of conventional passively mode-locked fibre lasers is fundamentally linked to the laser cavity length and is therefore typically ~10–100 MHz, which is orders of magnitude lower than required. Cascading stimulated Brillouin scattering (SBS) in nonlinear resonators, however, enables the formation of Brillouin frequency combs (BFCs) with GHz line spacing, which is determined by the acoustic properties of the medium and is independent of the resonator length. Phase-locking of such combs therefore holds a promise to achieve gigahertz repetition rate lasers. The interplay of SBS and Kerr-nonlinear four-wave mixing (FWM) in nonlinear resonators has been previously investigated, yet the phase relationship of the waves has not been considered. Here, we present for the first time experimental and numerical results that demonstrate phase-locking of BFCs generated in a nonlinear waveguide cavity. Using real-time measurements we demonstrate stable 40 ps pulse trains with 8 GHz repetition rate based on a chalcogenide fibre cavity, without the aid of any additional phase-locking element. Detailed numerical modelling, which is in agreement with the experimental results, highlight the essential role of FWM in phase-locking of the BFC.
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Affiliation(s)
- Thomas F S Büttner
- Centre for Ultrahigh bandwidth Devices for Optical Systems (CUDOS), Institute of Photonics and Optical Science (IPOS), School of Physics, University of Sydney, NSW, 2006, Australia
| | - Irina V Kabakova
- Centre for Ultrahigh bandwidth Devices for Optical Systems (CUDOS), Institute of Photonics and Optical Science (IPOS), School of Physics, University of Sydney, NSW, 2006, Australia
| | - Darren D Hudson
- Centre for Ultrahigh bandwidth Devices for Optical Systems (CUDOS), Institute of Photonics and Optical Science (IPOS), School of Physics, University of Sydney, NSW, 2006, Australia
| | - Ravi Pant
- Centre for Ultrahigh bandwidth Devices for Optical Systems (CUDOS), Institute of Photonics and Optical Science (IPOS), School of Physics, University of Sydney, NSW, 2006, Australia
| | - Christopher G Poulton
- 1] Centre for Ultrahigh bandwidth Devices for Optical Systems (CUDOS), Institute of Photonics and Optical Science (IPOS), School of Physics, University of Sydney, NSW, 2006, Australia [2] CUDOS, School of Mathematical Sciences, University of Technology, Sydney, NSW, 2007, Australia
| | - Alexander C Judge
- Centre for Ultrahigh bandwidth Devices for Optical Systems (CUDOS), Institute of Photonics and Optical Science (IPOS), School of Physics, University of Sydney, NSW, 2006, Australia
| | - Benjamin J Eggleton
- Centre for Ultrahigh bandwidth Devices for Optical Systems (CUDOS), Institute of Photonics and Optical Science (IPOS), School of Physics, University of Sydney, NSW, 2006, Australia
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Yoshida H, Hatae T, Fujita H, Nakatsuka M, Kitamura S. A high-energy 160-ps pulse generation by stimulated Brillouin scattering from heavy fluorocarbon liquid at 1064 nm wavelength. OPTICS EXPRESS 2009; 17:13654-13662. [PMID: 19654773 DOI: 10.1364/oe.17.013654] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We have achieved a high compression ratio by stimulated Brillouin scattering (SBS) consisting of two long cells. A 13-ns Nd:YAG laser pulse was temporally compressed to about 160-ps phase-conjugated pulse in heavy fluorocarbon FC-40 liquid at a 1064 nm wavelength. The maximum reflectivity of SBS process was over 80 % without an optical damage. The compressed pulse brightness was about 65-fold higher than that of the incident pulse.
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Affiliation(s)
- Hidetsugu Yoshida
- Institute of Laser Engineering, Osaka University, Suita, Osaka 565-0871, Japan.
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Kawase K, Kando M, Hayakawa T, Daito I, Kondo S, Homma T, Kameshima T, Kotaki H, Chen LM, Fukuda Y, Faenov A, Shizuma T, Fujiwara M, Bulanov SV, Kimura T, Tajima T. Sub-MeV tunably polarized X-ray production with laser Thomson backscattering. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2008; 79:053302. [PMID: 18513062 DOI: 10.1063/1.2931010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Reported in this article is the generation of unique polarized x-rays in the sub-MeV region by means of the Thomson backscattering of the Nd:YAG laser photon with a wavelength of 1064 nm on the 150 MeV electron from the microtron accelerator. The maximum energy of the x-ray photons is estimated to be about 400 keV. The total energy of the backscattered x-ray pulse is measured with an imaging plate and a LYSO scintillator. The angular divergence of the x-rays is also measured by using the imaging plate. We confirm that the x-ray beam is polarized according to the laser polarization direction with the Compton scattering method. In addition, we demonstrate the imaging of the object shielded by lead with the generated x-rays.
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Affiliation(s)
- K Kawase
- Kansai Photon Science Institute, Japan Atomic Energy Agency, 8-1 Umemidai, Kizugawa, Kyoto 619-0215, Japan
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Thurow B, Jiang N, Samimy M, Lempert W. Narrow-linewidth megahertz-rate pulse-burst laser for high-speed flow diagnostics. APPLIED OPTICS 2004; 43:5064-5073. [PMID: 15468708 DOI: 10.1364/ao.43.005064] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
A second-generation pulse-burst laser system for high-speed flow diagnostics is described in detail. The laser can produce a burst of high-energy pulses (of the order of hundreds of millijoules per pulse) with individual pulse durations of less than 10 ns and pulse separations as short as 1 micros. A key improvement is the addition of a phase-conjugate mirror, which effectively isolates the high-intensity, short-duration pulses from the low-intensity, long-duration background illumination. It allows for more-efficient amplification and harmonic generation, with efficiencies exceeding 50% for second-harmonic and 40% for third-harmonic generation. Characteristics of the laser system, including gain narrowing, pulse-burst energy distribution, pulse narrowing, and overall pulse-burst energy, are described. In addition, the applicability of the laser for spectroscopic-based flow diagnostics is demonstrated through the presentation of megahertz-rate planar Doppler velocimetry results.
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Affiliation(s)
- Brian Thurow
- Gas Dynamics and Turbulence Laboratory, The Ohio State University, Columbus, Ohio 43210, USA
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Dubinskii MA, Merkle LD. Ultrahigh-gain bulk solid-state stimulated Brillouin scattering phase-conjugation material. OPTICS LETTERS 2004; 29:992-994. [PMID: 15143651 DOI: 10.1364/ol.29.000992] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
We report what is believed to be the first observation of phase conjugation by stimulated Brillouin scattering (SBS) in TeO2 single crystal. The observed very low threshold for phase-conjugate mirror (PCM) formation, high PCM reflectivities in this initial experiment, and commercial availability of material hold promise for a host of practical applications in the near future. The resultant steady-state gain parameter, approximately 100 cm/GW, is to our knowledge the largest ever reported for any SBS material.
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Affiliation(s)
- Mark A Dubinskii
- U.S. Army Research Laboratory, AMSRD-ARL-SE-EO, 2800 Powder Mill Road, Adelphi, Maryland 20783, USA.
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Shilov AA, Pasmanik GA, Kulagin OV, Deki K. High-peak-power diode-pumped Nd:YAG laser with a Brillouin phase-conjugation--pulse-compression mirror. OPTICS LETTERS 2001; 26:1565-1567. [PMID: 18049664 DOI: 10.1364/ol.26.001565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
We demonstrate stimulated Brillouin scattering compression of diode-pumped Nd:YAG laser pulses with a 3-ns duration into 350-ps pulses at a pulse-repetition rate of 100 Hz for what is believed to be the first time. The output pulse energy was 6.5 mJ, with a beam-quality factor M(2) of 1.15, and after final amplification the energy reached 36 mJ, with M(2) of 2.5.
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