Compensation of laser beam directional stability offset error by using translational spectroscope

In order to improve the small range and poor dynamic performance of a flexible tilting mirror system for rapid compensation of laser beam directional stability offset error, a direct adjustment method is constructed by means of a translational spectroscope, which fixed on a piezoelectric actuator, to steer the laser beam to the collimating state, and to compensate for the displacement offset and angular offset of laser bean respectively. This method reduces the flexible rotation link in-between, avoids the backlash and lags error of friction and elastic deformation, and simplifies their control modes for the compensation process, thereby improving the control accuracy and dynamic performance of adjustment system. Experimental results show that, the tilted reflecting plane of the spectroscope can be used to steer the laser beam to the valid positions within the adjustment range up to 100μm, to compensate the offset error of the laser beam, or to compensate the vibration of laser source and the tilt error of detector installation, its control bandwidth above 100Hz. These results suggest this method can provide an effective solution for rapid precision collimation and compensation.