Row-gated optical phased array using integrated diodes for 3D structured light imaging

A monolithically integrated structured light (SL) imaging system based on a row-gated optical phased array (RG-OPA) is presented in this work, which achieves 3D sensing performance by gating the selected optical and electrical rows using an integrated diode and optical switch array. Several limitations of conventional SL systems need to be addressed, including inflexible light-field manipulation, suboptimal energy distribution in diffractive optical-element-based SL systems, and low permissible exposure power for eyes in visible-light-based SL systems. The proposed RG-OPA chip leverages 1550 nm illumination for improved ocular safety. It further utilizes on-chip diodes to realize a simplified circuit topology and enables single-wavelength 2D beam steering without wavelength tuning. By combining horizontal sub-OPAs for high-density dot array generation with vertical row-gated scanning, the system achieved a dense 2500 point array in the field of view. As proof of concept, we adopted an RG-OPA chip for 3D structured light imaging. The chip can effectively recover the 3D information of the target through an emitting point array. The experimental results demonstrate a measurement accuracy of ±1.5mm in the 1 m range and a maximum detection range of 5 m. This can resolve critical challenges in existing SL technologies, including restricted light-field programmability, circuit complexity, and safety concerns. The compact optoelectronic integrated architecture offers a high-precision, eye-safe, and cost-effective solution for 3D imaging, facial recognition, and large-scale scene reconstruction, highlighting its potential for broad industrial applications.