自由运行的半导体激光器列阵输出激光谱线较宽、中心波长易漂移。为此,本文采用体全息光栅(VBG)构成外腔半导体激光器阵列(EcLD)系统,利用体光栅能够稳定波长、压窄线宽的特点,从而克服上述缺点。实验表明:采用了VBG外腔反馈后,在最好的情况下,LDA的输出光谱宽度从自由运行时的2.3nm压窄到了0.96nm;在测试的环境温度变化范围内(14~31℃),LDA的峰值波长稳定在体光栅布拉格波长808nm处,输出光的线宽雏持在1.14nm之下;并且,在测试的偏置电流变化范围内(7~13A)峰值波长和谱宽无明显变化。
Free running semiconductor Laser Diode Array (LDA) is subject to wide line width and peak wavelength drift. In order to overcome the drawbacks, an External Cavity Laser Diode (ECLD) is constructed by adopting a Volume Bragg Grating (VBG). The experiments show that, after using the VBG reflector, the output spectral width is reduced to 0.96 nm, which is narrower than its original free running value of 2.3 nm. In addition, within the variation range of the coolant temperature (14-31 ℃), the peak wavelength of the VBG external cavity LDA is stabilized at the Bragg wavelength (808 nm) of the VBC, and the spectral width is kept below 1.14 nm. Experiments also show that the peak wavelength and the line width of the VBG external cavity LDA have no observable changes when the drive current of the LDA is varied from 7Ato 13A.