Circular Optical Phased Array with Large Steering Range and High Resolution

Area of Science:

• Photonics and Optical Engineering
• Integrated Optics
• Nanophotonics

Background:

• Optical phased arrays (OPAs) are crucial for applications like autonomous vehicles and free-space communications.
• Integrated silicon photonics enables miniaturized and efficient optical systems.
• Existing OPAs often face limitations in element spacing and beam steering capabilities.

Purpose of the Study:

• To design and numerically investigate novel two-dimensional optical phased arrays with a circular, concentric ring topology.
• To evaluate the performance of these arrays for both single-wavelength and broadband multi-wavelength operations.
• To explore the potential of these arrays for advanced on-chip photonic applications requiring fast, high-resolution beam steering.

Main Methods:

• Numerical investigation of two-dimensional OPAs with 110 and 820 elements arranged in concentric rings.
• Simulation of both single-wavelength (1550 nm) and broadband multi-wavelength (1535 nm to 1565 nm) operations.
• Analysis of beam steering capabilities, beam divergence, and main-to-sidelobe suppression ratio.

Main Results:

• Achieved narrow beam divergences of 0.5° (110-element) and 0.22° (820-element) with >10 dB main-to-sidelobe suppression.
• Demonstrated large element spacing beyond sub-wavelength limits due to the circular array topology.
• Obtained solid-angle beam steering up to 0.51π sr (single-wavelength) and 0.57π sr (multi-wavelength).

Conclusions:

• The proposed circular OPAs offer superior beam steering performance compared to traditional linear or rectangular arrays.
• This design enables efficient, wide-angle, and broadband beam steering suitable for integrated photonic applications.
• The findings open new avenues for advanced optical systems in sensing, communication, and autonomous technologies.