Achieving full grating-lobe-free field of view with low-complexity co-prime photonic beamforming transceivers

Abstract

Integrated photonic active beamforming can significantly reduce the size and cost of coherent imagers for LiDAR and medical imaging applications. In current architectures, the complexity of photonic and electronic circuitry linearly increases with the desired imaging resolution. We propose a novel photonic transceiver architecture based on co-prime sampling techniques that breaks this trade-off and achieves the full (radiating-element-limited) field of view (FOV) for a 2D aperture with a single-frequency laser. Using only order-of- N radiating elements, this architecture achieves beamwidth and sidelobe level (SLL) performance equivalent to a transceiver with order-of- N 2 elements with half-wavelength spacing. Furthermore, we incorporate a pulse amplitude modulation (PAM) row–column drive methodology to reduce the number of required electrical drivers for this architecture from order of N to order of N . A silicon photonics implementation of this architecture using two 64-element apertures, one for transmitting and one for receiving, requires only 34 PAM electrical drivers and achieves a transceiver SLL of − 11.3 dB with 1026 total resolvable spots, and 0.6° beamwidth within a 23 ° × 16.3 ° FOV.

Decoupling of temporal/spatial broadening effects in Doppler wind LiDAR by 2D spectral analysis

“…[6,7] Li-DAR (light detection and ranging), a widely used optical remote sensing tool, plays an increasingly important role. [8][9][10][11][12] Coherent detection and direct detection are two schemes used in Doppler LiDAR to obtain wind information. [13] The main difference between these two methods lies in the extraction of Doppler frequency shifts.…”

Manipulation of Photonic Jets of Topological Gratings Comprising ITO Strips and Nanowalls Using Refractive Indices of Dielectric Nanofilms

“…Optical gratings including phase gratings, binary gratings, surface relief gratings, Bragg gratings, and plasmonic gratings have many fascinating and groundbreaking applications, such as wave couplers for photonic circuits, [1][2][3][4] beam steering for imaging, [5][6][7][8] signal interconnection for communication, [9][10][11][12] holographic data DOI: 10.1002/lpor.202300659 storage for information processing, [13][14][15][16] and sensing for dielectric materials. [17][18][19][20] These applications rely on large diffraction angles, high efficiencies, and strong electromagnetic resonance of optical gratings.…”