In order to solve the power fluctuation problem of 3kW RF slab CO2 laser at high power operating conditions, a turning mirror adjusting method of out light path was adopt to compensate the light beam deviation caused by thermal deformation of cavity mirrors. The key technology of laser input power control by pulse width modulator based on TMS320LF2407 chip was studied. End mirror sampling power detection system of shaping light path was designed. And the compensation theory of out light adaptive regulation system was analyzed. The result shows that, the end mirror sampling laser power detection system of shaping light path has high linearity and the maximum error compared with reference power meter is ± 2. 59%. when using a piezoelectric ceramics microdisplacement driver of PA 100/T 14 to adjust and compensate the adaptive turning mirror with micro-motion distance less than 54μm, the light beam deviation will be less than 0. 8mm of slit width of spatial filter. After adjustment and compensation, the output power fluctuation declines from 18% to 2%, and reaches the compensation demand of beam deviation caused by thermal deformation of cavity mirror. The sidelobe of shaping light disappears and the best output mode is gotten. The research has the practical value for improvement of laser stead output power.%为了解决3kW射频板条CO2激光器在高功率工作条件下功率波动的问题,采用外光路转折镜调节方法对腔镜热畸变造成的光路偏移进行补偿.研究了基于芯片TMS320LF2407的脉宽调制器控制激光器注入功率的关键技术,设计了整形光路尾镜取样功率检测系统,并分析了外光路自适应调节系统的补偿原理.结果表明,整形光路尾镜取样功率检测系统与基准功率计的最大误差为±2.59%,其具有高线性度;采用PA 100/T 14型压电陶瓷微位移驱动器,对微动距离不超过54μm的自适应调节转折镜进行调节补偿,光束偏移不会超出空间滤波器的0.8mm狭缝宽度;调节补偿前后输出功率波动由18%降到2%,达到了由于腔镜热变形导致光束偏移的补偿要求,整形光束的旁瓣消失,获得最佳模式输出.此项研究对提高激光器输出功率稳定性具有一定的实用价值.
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