Small-angle measurement system enhanced by an optical phased array

Abstract

Small-angle measurement can be realized by embedding the laser beam in a reflective sector, within which multiple reflections enlarge the angle between the input and the output beams. However, the maximum detectable angle is limited by the detector aperture at the receiver side. In this work, we propose, to the best of our knowledge, a novel small-angle measurement system enhanced by an optical phased array (OPA), which is loaded on a spatial light modulator (SLM) to increase the maximum measurement range. The experimental results verify the effectiveness of the proposed system, and a wider measurement range with an unaffected measurement accuracy can be obtained. In the proof-of-concept demonstration, the measurement range of the system is enlarged by at least five times compared to the system without OPA, while maintaining the same measurement accuracy.