Qiang Fang
Research Subjects
Qiang Fang has a total of 31 co-authors. Here are the top co-authors by number of shared publications:
Wei Shi
6 shared publicationsJianquan Yao
5 shared publications- Quan Sheng
Tianjin University
4 shared publications - Wei Shi
Tianjin University
4 shared publications Xuelong Cui
4 shared publicationsYang Xu
3 shared publications
Latest Publications
- Open Access
Gain-Switched Er-Doped Fluoride Fiber Laser at ~3.75 μm
We demonstrate a pulsed Er-doped ZBLAN fiber laser operating at 3.75 μm based on the gain-switching scheme. A diffraction grating is introduced as a wavelength selection component to enable stable lasing in this long-wavelength region that deviates from the emission peak of 4F9/2→4I9/2 transition in Er3+. Different from the conventional gain-switching behavior where the pulse repetition frequency of the output laser is same as the that of the pump, the gain-switched laser demonstrated here shows a variable pulse repetition frequency, which accounts for 1/n (n = 4, 3, 2) of the pump pulse repetition frequency, in response to the 1950 nm pump power. The output pulse characteristics, including average output power, repetition frequency, pulse duration, and peak power, are investigated in detail. Over 200 mW average output power at 3.75 μm was obtained at 12 W of 1950 nm pump power. This work demonstrates that the Er-doped ZBLAN fiber laser, in combination with gain-switched scheme, is a feasible and promising approach to generate powerful pulsed emission > 3.7 μm.
Open AccessGain-Switched Er-Doped Fluoride Fiber Laser at ~3.75 μm
We demonstrate a pulsed Er-doped ZBLAN fiber laser operating at 3.75 μm based on the gain-switching scheme. A diffraction grating is introduced as a wavelength selection component to enable stable lasing in this long-wavelength region that deviates from the emission peak of 4F9/2→4I9/2 transition in Er3+. Different from the conventional gain-switching behavior where the pulse repetition frequency of the output laser is same as the that of the pump, the gain-switched laser demonstrated here shows a variable pulse repetition frequency, which accounts for 1/n (n = 4, 3, 2) of the pump pulse repetition frequency, in response to the 1950 nm pump power. The output pulse characteristics, including average output power, repetition frequency, pulse duration, and peak power, are investigated in detail. Over 200 mW average output power at 3.75 μm was obtained at 12 W of 1950 nm pump power. This work demonstrates that the Er-doped ZBLAN fiber laser, in combination with gain-switched scheme, is a feasible and promising approach to generate powerful pulsed emission > 3.7 μm.
- 5 January 2022
- Published by Elsevier in Optics Communications
- Vol. 511
1.5-kW all-fiberized Yb-doped MOPA laser at 1105 nm with near-diffraction-limited beam quality and narrow spectral width
- 5 January 2022
- Published by Elsevier in Optics Communications
- Vol. 511
1.5-kW all-fiberized Yb-doped MOPA laser at 1105 nm with near-diffraction-limited beam quality and narrow spectral width
- 23 April 2021
- Published by Optica Publishing Group in Applied Optics
- Vol. 60 (13) , 3740-3746
2.4 kW 1045 nm narrow-spectral-width monolithic single-mode CW fiber laser by using an FBG-based MOPA configuration
A 24 kW narrow-spectral-width near-diffraction-limited monolithic fiber laser system at ∼ 1045.2 n m in a fiber Bragg grating (FBG)-based master oscillator power amplifier (MOPA) configuration is demonstrated in this paper. The near-diffraction-limited beam quality ( M 2 ∼ 1.2 ) and a spectral width of 0.35 nm ( ∼ 96 G H z ) are achieved. The stimulated Raman scattering (SRS) is theoretically and experimentally investigated. The SRS has been suppressed by carefully optimizing the length of the Yb-doped fiber and the pumping scheme, and a signal-to-noise ratio of ∼ 33 d B between the laser signal and the Raman Stokes component is achieved. The stimulate Brillouin scattering and the transverse mode instability are not observed. To our best knowledge, this is the highest-output power for 104 × n m single-mode fiber laser with ∼ 96 G H z spectral width by using an FBG-based MOPA configuration.
- 23 April 2021
- Published by Optica Publishing Group in Applied Optics
- Vol. 60 (13) , 3740-3746
2.4 kW 1045 nm narrow-spectral-width monolithic single-mode CW fiber laser by using an FBG-based MOPA configuration
A 24 kW narrow-spectral-width near-diffraction-limited monolithic fiber laser system at ∼ 1045.2 n m in a fiber Bragg grating (FBG)-based master oscillator power amplifier (MOPA) configuration is demonstrated in this paper. The near-diffraction-limited beam quality ( M 2 ∼ 1.2 ) and a spectral width of 0.35 nm ( ∼ 96 G H z ) are achieved. The stimulated Raman scattering (SRS) is theoretically and experimentally investigated. The SRS has been suppressed by carefully optimizing the length of the Yb-doped fiber and the pumping scheme, and a signal-to-noise ratio of ∼ 33 d B between the laser signal and the Raman Stokes component is achieved. The stimulate Brillouin scattering and the transverse mode instability are not observed. To our best knowledge, this is the highest-output power for 104 × n m single-mode fiber laser with ∼ 96 G H z spectral width by using an FBG-based MOPA configuration.
- Open Access
- 30 April 2020
- Published by Elsevier in Results in Physics
- Vol. 17, 103136
All-fiber CW optical parametric oscillator tuned from 1642.5 to 1655.4 nm by a low-loss SMS filter
- 30 April 2020
- Published by Elsevier in Results in Physics
- Vol. 17, 103136
Open AccessAll-fiber CW optical parametric oscillator tuned from 1642.5 to 1655.4 nm by a low-loss SMS filter
- 24 October 2019
- Published by SPIE-Intl Soc Optical Eng in Optical Engineering
- Vol. 58 (10) , 106106-7
Hundred-watts-level monolithic narrow linewidth linearly-polarized fiber laser at 1018 nm
<!-- *** Custom HTML *** --> We theoretically and experimentally demonstrated an all-fiber, hundred-watts-level, linearly-polarized, narrow spectral linewidth laser amplifier at a central wavelength of 1018 nm based on master oscillator-power amplifier configuration, which is composed of a laser oscillator and one stage of the fiber amplifier. The laser system can generate 104-W output power with 3- and 20-dB spectral linewidth of ∼0.073 and ∼0.25 nm, respectively, and a higher polarization extinction ratio of ∼17.89 dB at 1018.3 nm was obtained. Theoretical analysis based on the rate equations was used to optimize the parameters of 1018-nm ytterbium-doped fiber laser system for the maximum suppression of amplified spontaneous emission (ASE). The ASE was well depressed based on the optimization for the parameters of the laser system including the seed power, seed spectrum, gain fiber length in the amplifier, etc. And ∼ 27-dB signal-to-noise ratio was achieved at the maximum output power. The slope efficiency for the amplifier stage can reach 79%, and near-diffraction-limited beam quality ( and ) was obtained.- 24 October 2019
- Published by SPIE-Intl Soc Optical Eng in Optical Engineering
- Vol. 58 (10) , 106106-7
Hundred-watts-level monolithic narrow linewidth linearly-polarized fiber laser at 1018 nm
<!-- *** Custom HTML *** --> We theoretically and experimentally demonstrated an all-fiber, hundred-watts-level, linearly-polarized, narrow spectral linewidth laser amplifier at a central wavelength of 1018 nm based on master oscillator-power amplifier configuration, which is composed of a laser oscillator and one stage of the fiber amplifier. The laser system can generate 104-W output power with 3- and 20-dB spectral linewidth of ∼0.073 and ∼0.25 nm, respectively, and a higher polarization extinction ratio of ∼17.89 dB at 1018.3 nm was obtained. Theoretical analysis based on the rate equations was used to optimize the parameters of 1018-nm ytterbium-doped fiber laser system for the maximum suppression of amplified spontaneous emission (ASE). The ASE was well depressed based on the optimization for the parameters of the laser system including the seed power, seed spectrum, gain fiber length in the amplifier, etc. And ∼ 27-dB signal-to-noise ratio was achieved at the maximum output power. The slope efficiency for the amplifier stage can reach 79%, and near-diffraction-limited beam quality ( and ) was obtained.- Open Access
- 26 August 2017
- Published by SPIE-Intl Soc Optical Eng in Optical Engineering
- Vol. 56 (08) , 086112-5
97-μJ single frequency linearly polarized nanosecond pulsed laser at 775 nm using frequency doubling of a high-energy fiber laser system
Rare-earth-doped glass fiber lasers have seen progressive developments in the past two decades in various aspects, such as high power, high energy, ultrashort pulse width, narrow linewidth (single frequency), etc.1,2 Fiber lasers can only operate in certain spectra range, such as 1,3 1.5,4 2,5 or ,6 due to the limit of the emission spectra for the rare-earth-elements doped in glasses. Due to the various nonlinear processes, including the Raman, frequency doubling, parametric processes, etc., fiber lasers have been utilized to generate a lot of very attractive coherent sources operating in ultraviolate,7 visible,8 midinfrared,9 and even THz ranges.10 Fiber-based construction of these laser systems enables robust, compact, and high performance operation.- 26 August 2017
- Published by SPIE-Intl Soc Optical Eng in Optical Engineering
- Vol. 56 (08) , 086112-5
Open Access97-μJ single frequency linearly polarized nanosecond pulsed laser at 775 nm using frequency doubling of a high-energy fiber laser system
Rare-earth-doped glass fiber lasers have seen progressive developments in the past two decades in various aspects, such as high power, high energy, ultrashort pulse width, narrow linewidth (single frequency), etc.1,2 Fiber lasers can only operate in certain spectra range, such as 1,3 1.5,4 2,5 or ,6 due to the limit of the emission spectra for the rare-earth-elements doped in glasses. Due to the various nonlinear processes, including the Raman, frequency doubling, parametric processes, etc., fiber lasers have been utilized to generate a lot of very attractive coherent sources operating in ultraviolate,7 visible,8 midinfrared,9 and even THz ranges.10 Fiber-based construction of these laser systems enables robust, compact, and high performance operation. - 11 March 2016
- Published by SPIE-Intl Soc Optical Eng
- p. 972811-972811-6
2μm single frequency fiber laser based on thulium-doped silica fiber
- 11 March 2016
- Published by SPIE-Intl Soc Optical Eng
- p. 972811-972811-6
2μm single frequency fiber laser based on thulium-doped silica fiber
- 15 April 2014
- Published by IOP Publishing in Laser Physics
- Vol. 24 (6) , 65102
300-W-average-power monolithic actively Q-switched fiber laser at 1064 nm
- 15 April 2014
- Published by IOP Publishing in Laser Physics
- Vol. 24 (6) , 65102
300-W-average-power monolithic actively Q-switched fiber laser at 1064 nm
- 6 March 2014
- Published by Institute of Electrical and Electronics Engineers (IEEE) in IEEE Photonics Technology Letters
- Vol. 26 (9) , 874-876
978 nm Single Frequency Actively $Q$ -Switched All Fiber LaserA single-frequency actively Q-switched all-fiber laser at 978 nm was developed using a 2-cm-long commercial ytterbium-doped silica fiber and a pair of silica-fiber-based Bragg gratings. The Q-switching is enabled by the stress-induced polarization modulation in the short linear fiber laser cavity. The laser generates actively Q-switched single-frequency laser pulses with a pulse repetition rate ranging from tens of kilohertz to hundreds of kilohertz. The pulse duration and the average/peak power have been characterized. This is, to the best of our knowledge, the first demonstration of a single-frequency all-fiber Q-switched laser below 1 μm using commercial highly ytterbium-doped silica fiber.
- 6 March 2014
- Published by Institute of Electrical and Electronics Engineers (IEEE) in IEEE Photonics Technology Letters
- Vol. 26 (9) , 874-876
978 nm Single Frequency Actively $Q$ -Switched All Fiber LaserA single-frequency actively Q-switched all-fiber laser at 978 nm was developed using a 2-cm-long commercial ytterbium-doped silica fiber and a pair of silica-fiber-based Bragg gratings. The Q-switching is enabled by the stress-induced polarization modulation in the short linear fiber laser cavity. The laser generates actively Q-switched single-frequency laser pulses with a pulse repetition rate ranging from tens of kilohertz to hundreds of kilohertz. The pulse duration and the average/peak power have been characterized. This is, to the best of our knowledge, the first demonstration of a single-frequency all-fiber Q-switched laser below 1 μm using commercial highly ytterbium-doped silica fiber.
- 1 January 2014
- Published by Optica Publishing Group
- p. STu2N.2
700kW peak power monolithic nanosecond pulsed fiber laser
We report a high peak power monolithic nanosecond pulsed fiber laser in MOPA configuration. The system can produce ~ 709 kW peak power for 3.3 ns fiber laser pulses at 10 kHz repetition rate.
- 1 January 2014
- Published by Optica Publishing Group
- p. STu2N.2
700kW peak power monolithic nanosecond pulsed fiber laser
We report a high peak power monolithic nanosecond pulsed fiber laser in MOPA configuration. The system can produce ~ 709 kW peak power for 3.3 ns fiber laser pulses at 10 kHz repetition rate.