采用双声光调制器光路快速偏转技术与自准直光栅法实现CO2激光全波段快调谐同光路输出。首先对声光调制器特性进行实验研究, 结果显示: 声光调制器偏转角度约为44°, 与运用布拉格方程计算结果相符; 且激光单次通过声光调制器移频量为4068 MHz,与声光驱动器射频频率一致, 将激光往返多次经声光调制器的移频量叠加。进而, 开展基于声光调制器的CO2激光快调谐实验研究, 运用两个对称布置的同驱动频率声光调制器补偿声光移频, 实现偏转光路振荡输出, 运用光栅法在直线光路中实现激光全波段可调谐输出。最终, 在声光调制器时序控制下, 实现双波长激光快调谐同光路输出, 选定激光波长的切换时间约为1 ms, 脉宽小于300 ns, 且双波长切换速度不受CO2激光跃迁谱带的限制。

A rapid tuning pulsed CO2 laser is presented using a blazed grating system and a pair of acousto-optic modulators. Firstly, the characteristics of acousto-optic modulators were studied through experimentation. The results showed that the deflection angle of the acousto-optic modulator was approximately 44°, which was in agreement with the calculations of the Bragg equation. When a single laser passed the acousto-optic modulator, the shift in frequency was approximately 4068 MHz, which was in agreement with the acousto-optic driving frequency. In addition, when multiple lasers passed through the acousto-optic modulator, the shift in frequency was compounded. Based on the acousto-optic modulator results, experimental research was performed on rapid tuning pulsed CO2 lasers. In order to offset the shift in acousto-optic frequency, two acousto-optic modulators were placed symmetrically in the deflected optical beam, and a laser output was obtained. Using a blazed grating, a full band tunable output laser was obtained in the linear optical beam. Finally, under sequential control of double acousto-optic modulators, a double wavelength laser with rapid tuning output and a common optical axis was obtained. The tuning time of the pulsed laser was approximately 1 ms, which pulsed at a width of less than 300 ns. The tuning speed of the pulsed laser was independent of the transition band of the CO2 laser.