A noise-sidebands-free and ultra-low relative intensity noise(RIN) 1.5 μm single-frequency fiber laser is demonstrated for the first time to our best knowledge. Utilizing a self-injection locking framework and a boos...A noise-sidebands-free and ultra-low relative intensity noise(RIN) 1.5 μm single-frequency fiber laser is demonstrated for the first time to our best knowledge. Utilizing a self-injection locking framework and a booster optical amplifier, the noise sidebands with relative amplitudes as high as 20 dB are completely suppressed.The RIN is remarkably reduced by more than 64 dB at the relaxation oscillation peak to retain below-150 dB∕Hz in a frequency range from 75 kHz to 50 MHz, while the quantum noise limit is -152.9 d B∕Hz.Furthermore, a laser linewidth narrower than 600 Hz, a polarization-extinction ratio of more than 23 dB, and an optical signal-to-noise ratio of more than 73 dB are acquired simultaneously. This noise-sidebands-free and ultralow-RIN single-frequency fiber laser is highly competitive in advanced coherent light detection fields including coherent Doppler wind lidar, high-speed coherent optical communication, and precise absolute distance coherent measurement.展开更多
Nd3+-doped fiber lasers at around 900 nm based on the 4F3/2→4I9/2 transition have obtained much research attention since they can be used as the laser sources for generating pure blue fiber lasers through the frequen...Nd3+-doped fiber lasers at around 900 nm based on the 4F3/2→4I9/2 transition have obtained much research attention since they can be used as the laser sources for generating pure blue fiber lasers through the frequency doubling.Here,an all-fiber laser at 915 nm was realized by polarization-maintaining Nd3+-doped silica fiber.A net gain per unit length of up to 1.0 dB/cm at 915 nm was obtained from a 4.5 cm fiber,which to our best knowledge is the highest gain coefficient reported in this kind of silica fiber.The optical-to-optical conversion efficiency varies with the active fiber length and the reflectivity of the output fiber Bragg grating(FBG),presenting an optimal value of 5.3%at 5.1 cm fiber length and 70%reflectivity of the low reflection FBG.Additionally,the linear distributed Bragg reflector short cavity was constructed to explore its potential in realizing single-frequency 915 nm fiber laser.The measurement result of longitudinal-mode properties shows it is still multi-longitudinal mode laser operation with 40 mm laser cavity.These results indicate that the Nd3+-doped silica fiber could be used to realize all-fiber laser at 915 nm,which presents potential to be the seed source of high-power fiber laser.展开更多
In this paper,a technique combining the cascaded energy-transfer pumping(CEP)method and master-oscillator power-amplifier(MOPA)configuration is proposed for power scaling of 1.6-μm-band single-frequency fiber lasers(...In this paper,a technique combining the cascaded energy-transfer pumping(CEP)method and master-oscillator power-amplifier(MOPA)configuration is proposed for power scaling of 1.6-μm-band single-frequency fiber lasers(SFFLs),where the Er^(3+)ion has a limited gain.The CEP technique is fulfilled by coupling a primary signal light at 1.6μm and a C-band auxiliary laser.The numerical model of the fiber amplifier with the CEP technique reveals that the energy transfer process involves the pump competition and the in-band particle transition between the signal and auxiliary lights.Moreover,for the signal emission,the population density in the upper level is enhanced,and the effective population inversion is achieved thanks to the CEP.A single-frequency MOPA laser at 1603 nm with an output power of 52.6 W and an improved slope efficiency of 30.4%is experimentally obtained through the CEP technique.Besides,a laser linewidth of 5.2 k Hz and a signal-to-auxiliary laser ratio of 60.7 d B are obtained at the maximum output power.The proposed technique is anticipated to be promising for increasing the slope efficiency and power scaling for fiber lasers operating at L band.展开更多
基金National Natural Science Foundation of China(NSFC)(11674103,61535014,61635004)Major Program of the National Natural Science Foundation of China(61790582)+3 种基金Fundamental Research Funds for Central Universities(2015ZM091,2017BQ002)China National Funds for Distinguished Young Scientists(61325024)Natural Science Foundation of Guangdong Province(2016A030310410,2017A030310007)Science and Technology Project of Guangdong(2014B050505007,2015B090926010,2016B090925004,2017B090911005)
文摘A noise-sidebands-free and ultra-low relative intensity noise(RIN) 1.5 μm single-frequency fiber laser is demonstrated for the first time to our best knowledge. Utilizing a self-injection locking framework and a booster optical amplifier, the noise sidebands with relative amplitudes as high as 20 dB are completely suppressed.The RIN is remarkably reduced by more than 64 dB at the relaxation oscillation peak to retain below-150 dB∕Hz in a frequency range from 75 kHz to 50 MHz, while the quantum noise limit is -152.9 d B∕Hz.Furthermore, a laser linewidth narrower than 600 Hz, a polarization-extinction ratio of more than 23 dB, and an optical signal-to-noise ratio of more than 73 dB are acquired simultaneously. This noise-sidebands-free and ultralow-RIN single-frequency fiber laser is highly competitive in advanced coherent light detection fields including coherent Doppler wind lidar, high-speed coherent optical communication, and precise absolute distance coherent measurement.
基金supported by the National Key Research and Development Plan(No.2017YFF0104504)Guangdong Natural Science Foundation(No.2018B030308009)+5 种基金National Natural Science Foundation of China(No.51672085)Program for Innovative Research Team in University of Ministry of Education of China(No.IRT_17R38)Joint Fund of Ministry of Education of China(No.6141A02033225)Local Innovative Research Team Project of “Pearl River Talent Plan”(No.2017BT01X137)Science and Technology Project of Guangdong(No.2017B090911005)Guangdong Key R&D Program(No.2018B090904003).
文摘Nd3+-doped fiber lasers at around 900 nm based on the 4F3/2→4I9/2 transition have obtained much research attention since they can be used as the laser sources for generating pure blue fiber lasers through the frequency doubling.Here,an all-fiber laser at 915 nm was realized by polarization-maintaining Nd3+-doped silica fiber.A net gain per unit length of up to 1.0 dB/cm at 915 nm was obtained from a 4.5 cm fiber,which to our best knowledge is the highest gain coefficient reported in this kind of silica fiber.The optical-to-optical conversion efficiency varies with the active fiber length and the reflectivity of the output fiber Bragg grating(FBG),presenting an optimal value of 5.3%at 5.1 cm fiber length and 70%reflectivity of the low reflection FBG.Additionally,the linear distributed Bragg reflector short cavity was constructed to explore its potential in realizing single-frequency 915 nm fiber laser.The measurement result of longitudinal-mode properties shows it is still multi-longitudinal mode laser operation with 40 mm laser cavity.These results indicate that the Nd3+-doped silica fiber could be used to realize all-fiber laser at 915 nm,which presents potential to be the seed source of high-power fiber laser.
基金National Key Research and Development Program of China(2017YFF0104602)Major Program of the National Natural Science Foundation of China(61790582)+4 种基金NSFC(11674103,51772101,61535014,61635004)Guangdong Key Research and Development Program(2018B090904001,2018B090904003)Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program(2017BT01X137)Natural Science Foundation of Guangdong Province(2016A030310410,2017A030310007)Science and Technology Project of Guangdong(2016B090925004,2017B090911005,201804020028)。
文摘In this paper,a technique combining the cascaded energy-transfer pumping(CEP)method and master-oscillator power-amplifier(MOPA)configuration is proposed for power scaling of 1.6-μm-band single-frequency fiber lasers(SFFLs),where the Er^(3+)ion has a limited gain.The CEP technique is fulfilled by coupling a primary signal light at 1.6μm and a C-band auxiliary laser.The numerical model of the fiber amplifier with the CEP technique reveals that the energy transfer process involves the pump competition and the in-band particle transition between the signal and auxiliary lights.Moreover,for the signal emission,the population density in the upper level is enhanced,and the effective population inversion is achieved thanks to the CEP.A single-frequency MOPA laser at 1603 nm with an output power of 52.6 W and an improved slope efficiency of 30.4%is experimentally obtained through the CEP technique.Besides,a laser linewidth of 5.2 k Hz and a signal-to-auxiliary laser ratio of 60.7 d B are obtained at the maximum output power.The proposed technique is anticipated to be promising for increasing the slope efficiency and power scaling for fiber lasers operating at L band.