为降低半导体激光主动照明红曝, 选择波长880 nm大功率半导体激光器作为新型激光主动照明成像系统光源。根据光纤耦合过程光参数积不变原理, 研制出波长880 nm大功率半导体激光器阵列单光纤耦合模块, 利用光纤匀光作用使激光光束匀化整圆后用于激光主动照明。首次在波长880 nm大功率半导体激光器上采用阶梯反射镜光束整形方法, 使激光光参数积与光纤匹配, 激光高效耦合进入纤芯400 μm、数值孔径0.22的光纤。室温条件下光纤耦合模块连续输出功率44.9 W, 电光转化效率35%, 波长880 nm大功率半导体激光器阵列光纤耦合模块, 不仅其红曝小而且对应CMOS图像传感器光谱响应度较高, 系统成像质量好。

Near-infrared laser diode arrays (LDA) are usually utilized as illuminated source for active laser illumination technology. The severe red exposure of 808nm LDA deteriorates its potential for military application. Due to the low response of CMOS to light beyond 900nm, LDA with 880nm wavelength is a good candidate for active laser illumination. The 880 nm LDA has been chosen as a new type of laser active illumination source. As the beam of the high-power LDA has large divergence and uneveness, the 880 nm LDA can not be used directly for active illumination. Thus high power 880 nm fiber-coupled diode lasers have been developed with a pair of micro step-mirrors for beam shaping. As a result, output power about 44.9 W of the fiber-coupled laser diode module is achieved, and electro-optical conversion efficiency is 35%.