Angle measurement using the integrated amplitude of difference beam from an optical phased array

We propose an angle measurement method by comparing the integrated amplitude of the difference beam (AMCIAD) generated by an optical phase array (OPA), which can be used to improve the precision of angle measurements. The AMCIAD utilizes the beam-forming capability of an OPA to improve upon the traditional method of angle measurement by comparing amplitude (AMCA). In the experiment, an on-chip OPA is used to generate the difference beams and scan the object. An algorithm is developed to calculate the angular position of the object from the reflected light. The experimental results demonstrate that AMCIAD improves the accuracy of angle measurement by about four times compared to AMCA (0.13° of AMCIAD and 0.60° of AMCA). Angular accuracy equivalent to ∼4% of the beam width is demonstrated.