Circular Optical Phased Array with Large Steering Range and High Resolution

Light detection and ranging systems based on optical phased arrays and integrated silicon photonics have sparked a surge of applications over the recent years. This includes applications in sensing, free-space communications, or autonomous vehicles, to name a few. Herein, we report a design of two-dimensional optical phased arrays, which are arranged in a grid of concentric rings. We numerically investigate two designs composed of 110 and 820 elements, respectively. Both single-wavelength (1550 nm) and broadband multi-wavelength (1535 nm to 1565 nm) operations are studied. The proposed phased arrays enable free-space beam steering, offering improved performance with narrow beam divergences of only 0.5 degrees and 0.22 degrees for the 110-element and 820-element arrays, respectively, with a main-to-sidelobe suppression ratio higher than 10 dB. The circular array topology also allows large element spacing far beyond the sub-wavelength-scaled limits that are present in one-dimensional linear or two-dimensional rectangular arrays. Under a single-wavelength operation, a solid-angle steering between 0.21 pi sr and 0.51 pi sr is obtained for 110- and 820-element arrays, respectively, while the beam steering spans the range of 0.24 pi sr and 0.57 pi sr for a multi-wavelength operation. This work opens new opportunities for future optical phased arrays in on-chip photonic applications, in which fast, high-resolution, and broadband beam steering is necessary.

Automated summary

Light detection and ranging systems based on optical phased arrays and integrated silicon photonics have been widely used in various applications. This paper presents a design of two-dimensional optical phased arrays with improved beam steering performance and large element spacing, which opens up new opportunities for on-chip photonic applications in the future.