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

Abstract

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.Keyword： laser collimation，directional stability，beam offset，dynamic performance，tilting mirror system， translational spectroscope.

Development of a small-size laser triangulation displacement sensor and temperature drift compensation method

“…In extreme temperatures, the change of temperature will cause mechanical hardware deformation, optical crystal distortion [10,11] and laser source pointing jitter [12], which finally result in the spatial position shift of laser imaging points. Li [13] proposed an adjustment method by using a translational beam splitter fixed on a piezoelectric actuator, which adjusted the laser beam to a collimated state so as to compensate for the laser beam offset. Wu [14] adopted a passive beam generated by image rotation and sum-frequency generation to improve the stability of laser beam pointing.…”