Passive optimization of pump noise transfer function by narrow band-pass filtering in femtosecond fiber lasers  

作　　者：Peng Qin Sijia Wang Minglie Hu Youjian Song 

机构地区：[1]Qian Xuesen Laboratory of Space Technology,China Academy of Space Technology,Beijing 100094,China [2]Ultrafast Laser Laboratory,Key Laboratory of Opto-electronic Information Technical Science of Ministry of Education,School of Precision Instruments and Opto-electronics Engineering,Tianjin University,Tianjin 300072,China

出　　处：《High Power Laser Science and Engineering》2019年第3期156-162,共7页高功率激光科学与工程（英文版）

基　　金：funded by the National Science and Technology Innovation Special Zone Program of China;Independent Innovation Project of China Academy of Space Technology;Science and Technology Innovation Research and Development Project of China Aerospace Science and Technology Corporation;National Natural Science Foundation of China (No. 61675150)

摘　　要：Fluctuation of pump power is one of the major sources of temporal and intensity noise in femtosecond fiber lasers.In this work,the transfer functions between the relative intensity noise(RIN)of the pump laser diode(LD)and the output RIN,between the RIN of the pump LD and timing jitter of femtosecond fiber lasers are systematically studied.It is demonstrated,for the first time to our knowledge,that the amplitude of the pump RIN transfer function can be effectively decreased by an intra-cavity narrow band-pass filter.In particular,for normal-dispersion lasers,the 3-d B bandwidth of the transfer function can also be narrowed by two-thirds,with a steeper falling edge.Furthermore,with the narrow band-pass filtering,the transfer function is almost independent of the net intra-cavity dispersion due to amplifier similariton formation.The proposed scheme can effectively isolate the pump-induced noise without the need of complex active pump LD control and intra-cavity dispersion management,thus providing an easy way for practical high-power,high-stability femtosecond fiber laser design and related high-precision applications outside the laboratory.Fluctuation of pump power is one of the major sources of temporal and intensity noise in femtosecond fiber lasers.In this work, the transfer functions between the relative intensity noise(RIN) of the pump laser diode(LD) and the output RIN, between the RIN of the pump LD and timing jitter of femtosecond fiber lasers are systematically studied.It is demonstrated, for the first time to our knowledge, that the amplitude of the pump RIN transfer function can be effectively decreased by an intra-cavity narrow band-pass filter. In particular, for normal-dispersion lasers, the 3-d B bandwidth of the transfer function can also be narrowed by two-thirds, with a steeper falling edge. Furthermore, with the narrow band-pass filtering, the transfer function is almost independent of the net intra-cavity dispersion due to amplifier similariton formation. The proposed scheme can effectively isolate the pump-induced noise without the need of complex active pump LD control and intra-cavity dispersion management, thus providing an easy way for practical high-power,high-stability femtosecond fiber laser design and related high-precision applications outside the laboratory.

关 键 词：BAND-PASS filter FEMTOSECOND fiber LASERS TRANSFER function 

分 类 号：TN2[电子电信—物理电子学]