Ultra‐Sparse Aperiodic Silicon Optical Phased Array Using High‐Performance Thermo‐Optic Phase Shifter

Abstract

Integrated optical phased array (OPA) is evolving into a transformational technology for LiDAR and free‐space optical communication systems due to its distinctive qualities of compact size, rapid scanning, and low cost. When the integrated OPA is utilized for long‐range vehicle LiDAR (300 m range), a large emission aperture (mm‐cm length) is required. However, a large aperture typically necessitates thousands of phase‐controlled emitters and consumes tens of watts when utilizing traditional thermo‐optic phase shifters. Here, an easy‐to‐understand theory is proposed and an ultra‐sparse aperiodic OPA is experimentally demonstrated with a large aperture (6 mm 5 mm) using just 120 phase‐controlled emitters. In the azimuthal () direction, high resolvable points of 1300 have attained within a field of view (FOV) beam steering range of . The consumed electric power is only 0.47 W thanks to the ultra‐sparse aperiodic spacing (50 average pitch) and the high‐performance optical phase shifters. The fabrication‐robust thermo‐optic phase shifter achieved high performance in all relevant aspects including power consumption (3.1 mW/), driving voltage (1.1 V for 2), insertion loss (0.6 dB), modulation bandwidth (34 kHz), and footprint (42 42 ), acting as an ideal phase tuning component in large‐scale photonic integrated circuits.