The pulsed single-longitudinal-mode(SLM)operation caused by the modal-gain difference in a repetitively passively Q-switched(PQS)laser is studied in detail.Firstly,the analytical expressions for the pulse buildup-time...The pulsed single-longitudinal-mode(SLM)operation caused by the modal-gain difference in a repetitively passively Q-switched(PQS)laser is studied in detail.Firstly,the analytical expressions for the pulse buildup-time difference of repetitively PQS four-level and quasi-three-level lasers have been developed respectively.Then,according to the temporal criterion,the required conditions for repetitively PQS four-level and quasi-three-level lasers to achieve SLM operation are analyzed.The analysis results show that in addition to the short cavity is conducive to obtaining the pulsed SLM laser,the use of a lower pump power(compared to the threshold power)will help to obtain a longer pulse buildup-time difference and thus enabling the SLM operation.Moreover,it is worth noting that for the quasi-three-level lasers,the pulse buildup-time difference also depends on the initial population inversion density.The results also reveal that setting resonator parameters that can obtain large initial population inversion density will be helpful to the SLM operation in both four-level and quasithree-level regimes.In addition,the use of saturable absorber with a low absorption cross-section ratio between the excited state and ground state also contributes to the realization of the SLM.Finally,the optimization model of passively Q-switched single-longitudinal-mode laser is established.In addition to predicting the output performance of the laser,this model can also be used to obtain the optimal resonator parameters and the upper limit of pump power for SLM operation.展开更多
We present a Tm-doped fiber laser pumped Fabry-Perot etalons Ho：YAG laser based on a corner cube. A maximum single-longitudinal-mode and fundamental transverse mode output power of 478 m W at the wavelength of 2091.0...We present a Tm-doped fiber laser pumped Fabry-Perot etalons Ho：YAG laser based on a corner cube. A maximum single-longitudinal-mode and fundamental transverse mode output power of 478 m W at the wavelength of 2091.06 nm is achieved with a pump power of 16.3 W, corresponding to an optical-to-optical efficiency of 2.9% and a slope efficiency of 7.9%. The single-longitudinal-mode and fundamental transverse mode are less sensitive to the rotating of the corner cube. The results indicate the potential impact of a single-longitudinal-mode Ho： YA G laser with corner cube geometry to improve the anti-maladjustment stability.展开更多
A black phosphorus (BP) saturable absorber (SA) solution with different concentrations (1.0 and 0.5 mg/ml) is fabricated with the liquid-phase exfoliation method. By using the BP-SA, a compact diode-pumped passively Q...A black phosphorus (BP) saturable absorber (SA) solution with different concentrations (1.0 and 0.5 mg/ml) is fabricated with the liquid-phase exfoliation method. By using the BP-SA, a compact diode-pumped passively Q-switched Nd:YVO4 laser is demonstrated. One reflecting Bragg gratings is used as the output coupler for mode selection. By inserting those BP-SA solutions in the laser cavity, the maximum single longitude mode, Q-switched output powers of 126mW at 692.5 kHz and 149mW at 630.3 kHz are achieved at the pump power of 8.0 W, corresponding to the pulse durations of 144 ns and 196 ns, respectively. Moreover, longitudinal-mode characteristics of Q-switched output laser in different optical cavity lengths based on two-kind BP-SA solution concentrations are investigated. Our results show that BP-SA could also be developed as an effective SA for the Q-switched, single longitudinal mode pulse laser.展开更多
We demonstrate a high power,Er:Lu AG single-longitudinal-mode laser in an anti-misaligned resonator.Based on the Faraday effect,a 1.61 W single-longitudinal-mode(SLM)laser is obtained with the double corner-cube-retro...We demonstrate a high power,Er:Lu AG single-longitudinal-mode laser in an anti-misaligned resonator.Based on the Faraday effect,a 1.61 W single-longitudinal-mode(SLM)laser is obtained with the double corner-cube-retroreflector(CCR)structure,and the tunable wavelength is 1649.2-1650.3 nm.Additionally,we investigate the anti-misalignment characteristics when the CCR moves and rotates along the optical axis.Furthermore,by utilizing the Er:Lu AG amplifier,the maximum 2.32 W single-longitudinal-mode laser at 1649.6 nm is achieved.The beam quality factors M^(2) of the 2.32 W Er:Lu AG single-longitudinal-mode laser are 1.23 and 1.25 along the horizontal(x)and vertical(y)directions,respectively.展开更多
We propose and demonstrate a dual-wavelength single-longitudinal-mode(SLM) fiber laser with switchable wavelength spacing based on a graphene saturable absorber(GSA) and a Wave Shaper. By virtue of the excellent satur...We propose and demonstrate a dual-wavelength single-longitudinal-mode(SLM) fiber laser with switchable wavelength spacing based on a graphene saturable absorber(GSA) and a Wave Shaper. By virtue of the excellent saturable absorption ability of graphene, the linewidths of the lasing wavelengths can be effectively reduced and eventually SLM operation can be obtained. The linewidths of both wavelengths are measured to be narrower than 7.3 kHz. The obtained results suggest that the graphene would be a good candidate nonlinear optical material for applications in related photonic fields, such as SLM oscillation generation for microwave generation and optical sensing.展开更多
A tunable single-longitudinal-mode（SLM） semiconductor optical amplifier（SOA）-based fiber laser based on a dispersion-shifted fiber（DSF） is proposed and successfully demonstrated. SLM operation is obtained due to...A tunable single-longitudinal-mode（SLM） semiconductor optical amplifier（SOA）-based fiber laser based on a dispersion-shifted fiber（DSF） is proposed and successfully demonstrated. SLM operation is obtained due to the spectral narrowing effect resulting from inverse four-wave mixing in a DSF. A tunable optical filter performs wavelength selection function. By inserting a length of DSF in the laser cavity, SLM lasing can possibly be obtained when laser oscillation is stably established after traveling through the DSF many roundtrips. Stable tunable SLM oscillation with a signal-to-noise ratio as high as 65 dB over a wavelength range of about 35 nm is achieved experimentally, and each spectral linewidth is less than 6.5 kHz.展开更多
We report a single-frequency linearly polarized Q-switched fiber laser based on an Nb_(2)GeTe_(4)saturable absorber(SA).The Nb_(2)GeTe_(4)SA triggers passive Q-switching of the laser,and an un-pumped Yb-doped fiber to...We report a single-frequency linearly polarized Q-switched fiber laser based on an Nb_(2)GeTe_(4)saturable absorber(SA).The Nb_(2)GeTe_(4)SA triggers passive Q-switching of the laser,and an un-pumped Yb-doped fiber together with a 0.08-nmbandwidth polarization-maintaining fiber Bragg grating(FBG)acts as an ultra-narrow bandwidth filter to realize singlelongitudinal-mode(SLM)oscillation.The devices used in the laser are all kept polarized,so as to ensure linearly polarized laser output.Stable SLM linearly polarized Q-switching operation at 1064.6 nm is successfully achieved,producing a laser with a shortest pulse width of 1.36μs,a linewidth of 28.4 MHz,a repetition rate of 28.3 kHz-95.9 kHz,and a polarization extinction ratio of about 30 dB.It is believed that the single-frequency linearly polarized pulsed fiber laser studied in this paper has great application value in gravitational wave detection,beam combining,nonlinear frequency conversion,and other fields.展开更多
A laser sensing system based on beat frequency demodulation is proposed. The sensor uses a single-longitudinal-mode distributed Bragg reflector （DBR） fiber laser as a sensing element. This laser sensor has great mul...A laser sensing system based on beat frequency demodulation is proposed. The sensor uses a single-longitudinal-mode distributed Bragg reflector （DBR） fiber laser as a sensing element. This laser sensor has great multiplexing capability due to its wide free spectral range. Wavelength-division-multiplex （WDM） and frequency-division-multiplex （FDM） techniques are studied. The sensing system has high sensitivity and multiplexing channels.展开更多
基金Project supported by National Natural Science Foundation of China(Grant No.62205102)。
文摘The pulsed single-longitudinal-mode(SLM)operation caused by the modal-gain difference in a repetitively passively Q-switched(PQS)laser is studied in detail.Firstly,the analytical expressions for the pulse buildup-time difference of repetitively PQS four-level and quasi-three-level lasers have been developed respectively.Then,according to the temporal criterion,the required conditions for repetitively PQS four-level and quasi-three-level lasers to achieve SLM operation are analyzed.The analysis results show that in addition to the short cavity is conducive to obtaining the pulsed SLM laser,the use of a lower pump power(compared to the threshold power)will help to obtain a longer pulse buildup-time difference and thus enabling the SLM operation.Moreover,it is worth noting that for the quasi-three-level lasers,the pulse buildup-time difference also depends on the initial population inversion density.The results also reveal that setting resonator parameters that can obtain large initial population inversion density will be helpful to the SLM operation in both four-level and quasithree-level regimes.In addition,the use of saturable absorber with a low absorption cross-section ratio between the excited state and ground state also contributes to the realization of the SLM.Finally,the optimization model of passively Q-switched single-longitudinal-mode laser is established.In addition to predicting the output performance of the laser,this model can also be used to obtain the optimal resonator parameters and the upper limit of pump power for SLM operation.
基金Supported by the National Natural Science Foundation of China under Grant Nos 61308009 and 61405047the China Postdoctoral Science Foundation Funded Project under Grant No 2013M540288+2 种基金the Fundamental Research Funds for the Central Universities under Grant Nos HIT.NSRIF.2014044 and HIT.NSRIF.2015042the Science Fund for Outstanding Youths of Heilongjiang Province under Grant No JQ201310the Heilongjiang Postdoctoral Science Foundation Funded Project under Grant No LBH-Z14085
文摘We present a Tm-doped fiber laser pumped Fabry-Perot etalons Ho：YAG laser based on a corner cube. A maximum single-longitudinal-mode and fundamental transverse mode output power of 478 m W at the wavelength of 2091.06 nm is achieved with a pump power of 16.3 W, corresponding to an optical-to-optical efficiency of 2.9% and a slope efficiency of 7.9%. The single-longitudinal-mode and fundamental transverse mode are less sensitive to the rotating of the corner cube. The results indicate the potential impact of a single-longitudinal-mode Ho： YA G laser with corner cube geometry to improve the anti-maladjustment stability.
基金Supported by West Young Scholar Foundation of the Chinese Academy of Sciences under Grant No XAB2015B27
文摘A black phosphorus (BP) saturable absorber (SA) solution with different concentrations (1.0 and 0.5 mg/ml) is fabricated with the liquid-phase exfoliation method. By using the BP-SA, a compact diode-pumped passively Q-switched Nd:YVO4 laser is demonstrated. One reflecting Bragg gratings is used as the output coupler for mode selection. By inserting those BP-SA solutions in the laser cavity, the maximum single longitude mode, Q-switched output powers of 126mW at 692.5 kHz and 149mW at 630.3 kHz are achieved at the pump power of 8.0 W, corresponding to the pulse durations of 144 ns and 196 ns, respectively. Moreover, longitudinal-mode characteristics of Q-switched output laser in different optical cavity lengths based on two-kind BP-SA solution concentrations are investigated. Our results show that BP-SA could also be developed as an effective SA for the Q-switched, single longitudinal mode pulse laser.
基金supported by the National Natural Science Foundation of China(Nos.U20A20214 and 62275067)。
文摘We demonstrate a high power,Er:Lu AG single-longitudinal-mode laser in an anti-misaligned resonator.Based on the Faraday effect,a 1.61 W single-longitudinal-mode(SLM)laser is obtained with the double corner-cube-retroreflector(CCR)structure,and the tunable wavelength is 1649.2-1650.3 nm.Additionally,we investigate the anti-misalignment characteristics when the CCR moves and rotates along the optical axis.Furthermore,by utilizing the Er:Lu AG amplifier,the maximum 2.32 W single-longitudinal-mode laser at 1649.6 nm is achieved.The beam quality factors M^(2) of the 2.32 W Er:Lu AG single-longitudinal-mode laser are 1.23 and 1.25 along the horizontal(x)and vertical(y)directions,respectively.
基金supported by the National Natural Science Foundation of China (No. 61475065)
文摘We propose and demonstrate a dual-wavelength single-longitudinal-mode(SLM) fiber laser with switchable wavelength spacing based on a graphene saturable absorber(GSA) and a Wave Shaper. By virtue of the excellent saturable absorption ability of graphene, the linewidths of the lasing wavelengths can be effectively reduced and eventually SLM operation can be obtained. The linewidths of both wavelengths are measured to be narrower than 7.3 kHz. The obtained results suggest that the graphene would be a good candidate nonlinear optical material for applications in related photonic fields, such as SLM oscillation generation for microwave generation and optical sensing.
基金supported by the National Natural Science Foundation of China(No.61475065)the Guangdong Natural Science Foundation of China(No.2015A030313322)
文摘A tunable single-longitudinal-mode（SLM） semiconductor optical amplifier（SOA）-based fiber laser based on a dispersion-shifted fiber（DSF） is proposed and successfully demonstrated. SLM operation is obtained due to the spectral narrowing effect resulting from inverse four-wave mixing in a DSF. A tunable optical filter performs wavelength selection function. By inserting a length of DSF in the laser cavity, SLM lasing can possibly be obtained when laser oscillation is stably established after traveling through the DSF many roundtrips. Stable tunable SLM oscillation with a signal-to-noise ratio as high as 65 dB over a wavelength range of about 35 nm is achieved experimentally, and each spectral linewidth is less than 6.5 kHz.
基金Project supported by the National Natural Science Foundation of China(Grant No.62275272)the Training Program for Excellent Young Innovators of Changsha,China(Grant No.KQ2206003).
文摘We report a single-frequency linearly polarized Q-switched fiber laser based on an Nb_(2)GeTe_(4)saturable absorber(SA).The Nb_(2)GeTe_(4)SA triggers passive Q-switching of the laser,and an un-pumped Yb-doped fiber together with a 0.08-nmbandwidth polarization-maintaining fiber Bragg grating(FBG)acts as an ultra-narrow bandwidth filter to realize singlelongitudinal-mode(SLM)oscillation.The devices used in the laser are all kept polarized,so as to ensure linearly polarized laser output.Stable SLM linearly polarized Q-switching operation at 1064.6 nm is successfully achieved,producing a laser with a shortest pulse width of 1.36μs,a linewidth of 28.4 MHz,a repetition rate of 28.3 kHz-95.9 kHz,and a polarization extinction ratio of about 30 dB.It is believed that the single-frequency linearly polarized pulsed fiber laser studied in this paper has great application value in gravitational wave detection,beam combining,nonlinear frequency conversion,and other fields.
基金supported by the National 863 Program under Grant No. 2006AA01Z217the National Natural Science Foundation of China under Grant No. 60736039College Science Research Foundation of Tianjin and the Key Laboratory of Optoelectronic Information Technical Science, Ministry of Education of China under Grant No. 2006BA28
文摘A laser sensing system based on beat frequency demodulation is proposed. The sensor uses a single-longitudinal-mode distributed Bragg reflector （DBR） fiber laser as a sensing element. This laser sensor has great multiplexing capability due to its wide free spectral range. Wavelength-division-multiplex （WDM） and frequency-division-multiplex （FDM） techniques are studied. The sensing system has high sensitivity and multiplexing channels.
