Silicon nitride integrated two-dimensional wavelength tuning optical phased array

Abstract

Optical phased arrays (OPAs) have attracted much attention due to its potential applications in a series of advanced technologies such as LIDAR, free space communication. OPAs have many advantages, such as non-mechanical, arbitrary beam shaping and control. It has been proved that it is feasible to process OPAs with integrated optical platform. Among all the integrated optical platforms, silicon photonic platform has attracted the attention of most researchers and has achieved many important results. However, silicon photonic platform is very sensitive to processing errors and is not suitable for high power input because of its strong nonlinear effect. Silicon nitride (Si₃N₄) has become a research hotspot in integrated photonics due to its weak nonlinear effect and low-loss. Compared with silicon, because of its lower refractive index contrast, it is more tolerant to process changes and because of its weak nonlinear effect, it can allow higher power input, which is very suitable for processing OPAs. In this work, we propose an OPA based on 200 nm silicon nitride platform to control the two-dimensional direction of the beam by wavelength tuning. The system is simulated by FDTD solution. Finally, the scanning range of 46°×12° is realized in the wavelength range of 1500 nm to 1600 nm. The 3 dB size of a single spot is 1.8°×0.5° and a total of 600 scanning points can be obtained. This OPA can find applications in laser scanning, spectroscopy, demultiplexing and spectral pulse shaping applications.