Integrated optical phased arrays with circular architecture on a silicon platform

Optical phased arrays (OPAs) are now at the forefront of photonic research as a key beam steering technology for myriad of photonic applications, including in light detection and ranging (LIDAR), communications, and metrology, among others. Integrated OPAs with narrow beam widths and wide-angle steering are in critical need, especially for LIDARs in autonomous vehicle, drone and airplane navigation, or satellites. In this work, we numerically study the performances of OPAs having a circular layout arrangement. Compared to recently available solutions with 1D linear or 2D rectangular arrays, the proposed circular OPAs are poised to deliver effective suppression of the grating sidelobes, while improving beam steering range and obtaining narrower beamwidths. We demonstrate 110-element circular arrays with sidelobe suppression better than 10 dB and an angular beamwidth of 0.5°. Under a monochromatic operation at a 1550 nm wavelength, such array provides a solid angle steering range of 0.21π-sr, with a perspective for performance improvement by using large number of OPA elements and operating under broader spectral range.