Optical beam steering and distance measurement experiments through an optical phased array and a 3D printed lens

摘要

We present beam steering experiments based on the wavelength tuning of edge-coupled 1D optical phased arrays (OPAs) on a 3 µm silicon on insulator (SOI) platform. Two versions of 512-channel OPA with different pitch values, namely 2 µm and 3 µm, are designed, fabricated, and characterized. For the 2 µm pitch, the width of the output array is 1 mm, steering sensitivity is measured to be 1°/nm, and the maximum beam steering angle is 45°. For the 3 µm pitch, the output array is 1.5 mm wide, the steering sensitivity is 0.6°/nm, and the maximum beam steering angle is 30°. Since the chip doesn't offer vertical collimation, both a cylindrical (2D-shaped) lens and a 3D printed (3D-shaped) lens were tested with the OPA chips. The high number of output channels results in a wide width of the output array, therefore enabling frequency-modulated continuous-wave (FMCW) distance measurements up to a few meters. The ability to achieve precise steering angles and distance measurements with up to 5 cm accuracy improves the efficiency of light detection and ranging (LiDAR) systems in various fields, such as autonomous vehicles, robotics, and environmental mapping.