A tunable dual-wavelength Er3+-doped fiber laser based on self-feedback light injection

作者：He, Wei; Zhu, Lian-Qing^*; Lou, Xiao-Ping; Dong, Ming-Li; Zhang, Yin-Min; Luo, Fei; Chen, Xiao-Huai

来源：Journal of Optoelectronics.laser, 2014, 25(6): 1080-1085.

• Doped fiber
• Dual wavelength fiber lasers
• Dual wavelength laser
• Dual-wavelength outputs
• Experimental verification
• Light injection
• Single wavelength lasers
• Variable attenuators

In order to realize a tunable dual-wavelength laser output, an Er3+-doped fiber laser based on self-feedback light injection is proposed, and the theoretical analysis and experimental verification are presented in detail. In the designed configuration, one 976 nm laser diode (LD) is used for pumping, Er3+-doped fiber (EDF) is adopted as the gain medium, the laser cavity is composed of a fiber loop mirror (FLM) and two FBGs, and a saturable absorber (SA) is used to improve the output laser stability. In order to improve the laser stability and restrain the mode hopping, the output laser from FLM is used as self-feedback light which is coupled into the cavity by a 90:10 coupler. The interference is shown when injection light and oscillating light transmit in the cavity, a weak Bragg grating is generated and some certain waves can be restrained, so that a fiber laser with stable output is achieved. A switchable single-wavelength and dual-wavelength laser is achieved by adjusting the variable attenuator between two FBGs. In the experiment, an EDF of 4 m length is selected as the SA, and an EDF of 6 m length is adopted as the gain medium. In the end, the threshold is reduced from 28 mW to 25 mW after self-feedback light is injected into the cavity. When pump power is 80 mW, a stable tunable dual-wavelength output is realized by adjusting the variable attenuator (VA). When the pump power is improved, the single wavelength laser at 1 540 nm and 1 545 nm is measured and the power is 1.16 mW and 1.89 mW, respectively, and the SNR is greater than 50 dB. A stable and tunable dual-wavelength Er3+-doped fiber laser is achieved by self-feedback light injection structure and SA, which can optimize the system and improve the working efficiency.

• 出版日期2014-6
• 单位合肥工业大学