基于少数层石墨烯可饱和吸收的锁模光纤激光器

Few-layer graphene membrane as an ultrafast mode-locker in erbium-doped fiber laser

本文利用化学气相沉积法高温分解甲烷在铜箔上制得单层石墨烯薄膜,测量了石墨烯的拉曼光谱.将石墨烯薄膜逐层转移到光纤跳线的氧化锆插芯端面上做成可饱和吸收材料,实验研究了环形腔掺铒光纤脉冲激光器的输出特性,获得了峰值波长为1560.1nm,3dB带宽为0.27nm,重复频率为7.69MHz,脉冲宽度为58.8ps的锁模脉冲序列.时间带宽积为1.98,表明脉冲出现了啁啾.最后,通过改变两个光纤活动接头之间的空气腔的长度,激光波长实现了4nm的调谐.

Single-layer graphene film is fabricated on the copper foil by using chemical vapor deposition method, and the corresponding Raman spectrum is measured. The graphene membrane is transferred to the facet of zirconium oxide of a fiber jumper. The mode-lock Er-doped fiber laser with few-layer graphene membrane as saturable absorber is experimentally studied, which has a ring structure and uses a 10% portion of a fiber coupler as the laser output. The laser generates a pulse train at a 7.69 MHz repetition rate, with a full width at half maximum of 58.8 ps. The corresponding time-bandwidth product is 1.98, indicating that the pulses are chirped. The peak wavelength and 3 dB bandwidth of the laser are 1560.1 nm and 0.27 nm respectively. Through changing the air gap between two the fiber ends, 4 nm wavelength tuning is observed.