为了得到脉宽可调谐的双脉冲激光器，提出了基于半导体光放大器的8字腔激光器结构。该方案中，将半导体光放大器置于非线性光纤环镜的非对称位置，应用半导体光放大器的非线性偏振旋转产生激光脉冲，当半导体光放大器的驱动电流为200 mA 时，通过调整腔内的偏振控制器，得到重复频率为10.05 MHz和12.70 MHz,脉冲宽度分别为33.40 ns和30.08 ns的双脉冲，同时改变激光器腔长以及半导体光放大器在非线性放大镜中的位置，应用非线性光纤环镜的开关特性，双脉冲的脉宽也做相应的改变。

Key Laboratory of Film Electronics and Communication Devices. In order to obtain double-pulse with tunable pulse width, a scheme of laser structure based on semiconductor optical amplifier (SOA) is proposed. In this scheme, the SOA is put asymmetric in the nonlinear optical fiber loop mirror, pulse produced by nonlinear polarization rotation of the SOA. when the drive current of the SOA is up to 200 mA, through adjusting the polarization controller, double-pulses with pulse durations of 33.40 ns and 30.08 ns, with frequency repetitions of 10.05 MHz and 12.70 MHz are achieved, respectively. By changing the cavity length of the laser and the position of the SOA in the nonlinear amplifying loop mirror (NALM), double-pulse width changes accordingly due to the switch characteristics of the NALM.