为差分测量NO2气体浓度, 获得448.1 nm与449.15 nm的双波长双脉冲光源具有重要价值。实验中采用分时高压方波驱动电光Q开关, 在一次闪光灯抽运条件下, 在同一光路上实现了双波长、双脉冲的Cr∶LiSAF可调谐激光输出。利用一块波长为900 nm倍频切割的LBO晶体, 进行腔外的双波长双脉冲的谐波研究, 实现单光束双波长、双脉冲Cr∶LiSAF调Q谐波激光输出, 获得了波长分别为448.1 nm与449.15 nm同光束双波长激光输出, 脉冲能量分别为13.7 mJ, 脉冲间隔62 μs。输出的谐波光束线宽小于0.02 nm。

The dual wavelength and dual pulse light source with wavelengths of 448.1 nm and 449.15 nm have potential application in differential absorption lidar (DIAL) for measuring NO2 concentration in atmosphere. A dual wavelength (896.2 nm and 898.3 nm) and dual pulse Cr∶LiSAF laser output is achieved adopting the high pressure and square wave to drive the electric light Q-switch. Using one LBO crystal as the frequency doubling crystal, a dual wavelength (448.1 nm and 449.15 nm) and dual pulse laser is got. The output for one wavelength is about 13.7 mJ, the line width is less than 0.02 nm, and the time interval for two pulse in one pumping is about 62 μs.