【摘要】 分别将氧化石墨烯可饱和吸收镜(GOSAM)与半导体可饱和吸收镜(SESAM)作为可饱和吸收体,在同一掺铒光纤激光器中均实现了全光纤结构、稳定的锁模飞秒脉冲输出。实验用抽运源为中心波长974 nm的半导体激光器,抽运1.4 m长的吸收率为7 d B/m的掺铒光纤,谐振腔总腔长约为12 m。以GOSAM作为可饱和吸收体,当抽运功率为29 m W时,激光器产生稳定的锁模脉冲输出,脉冲宽度最窄为703 fs,光谱中心波长为1557.67 nm,3 d B带宽为3.91 nm。使用调制深度为18%的SESAM作为可饱和吸收体,当抽运功率为32 m W时也可得到锁模脉冲,脉冲宽度为542 fs,光谱中心波长为1561.5 nm,3 d B带宽为5.41 nm。实验表明,新型激光锁模器件氧化石墨烯的可饱和吸收效应可与SESAM媲美,且兼具价格低廉、制备简单的优势,在实现超短脉冲运转方面具有广阔的实际应用前景。更多还原

【Abstract】 The all-fiber passively mode-locked erbium-doped femtosecond fiber lasers based on semiconductor saturable absorber mirror(SESAM) and graphene oxide saturable absorber mirror(GOSAM) in the same cavity are demonstrated. The fiber ring laser is constituted with 1.4 m Er3+-doped fiber as gain medium, which is pumped by974 nm diode laser, and with the total cavity length of 12 m. Stable mode-locked laser pulse train occurrs at 29 m W incident pump power by employing GOSAM as the saturable absorber. The pulse width is measured to be 703 fs,and the center wavelength is 1557.67 nm, and 3 d B spectral bandwidth is corresponding to 3.91 nm. However,inserting SESAM with a modulation depth of 18% in the configuration mentioned above, we can obtain ultrashort pulse at 32 m W pump power, and the pulse width decreases to 542 fs. The laser center wavelength and the 3 d B spectral bandwidth are 1561.5 nm and 5.41 nm, respectively. Experimental results show that the novel mode-locking device—graphene oxide has the similiar distinguished saturable absorber ability. With its advantages of low price,simple preparation, it seems to be a good candidate for saturable absorbers in achieving ultrashort pulse operation.更多还原