Work

FMCW LiDAR with a GaN-based distributed feedback laser diode at 466 nm

Year: 2026

Type: article

Abstract: Frequency-modulated continuous-wave (FMCW) LiDAR requires a visible narrow-linewidth laser capable of a wide linear chirp for operations in underwater environments. To this end, we evaluated a GaN-based 466 nm distributed feedback laser diode (DFB-LD) using a delayed self-heterodyne interferometer, measuring its modulation waveform. The chirp span reached a 12.2 GHz peak-to-peak value (Fourier-limited theoretical resolution: 0.92 cm in the water). The modulation nonlinearity was 9% full scale, and the coherence length was 14 m (β-separation linewidth: 1.9 MHz). Using the proposed LD, we demonstrated free-space FMCW LiDAR at ∼3 m without predistortion. Although the resolution degraded to ∼2 m due to nonlinearity and frequency noise, this work represents, to our knowledge, the first experimental demonstration of FMCW LiDAR using a visible DFB-LD, showing its potential for visible coherent sensing.

Source: Optics Express

DOI: 10.1364/oe.585712

Authors: Wataru Kokuyama, Hidemi Tsuchida, Yoshiaki Nakajima

Institution: Toho University

Language: English

Topic: Advanced Optical Sensing Technologies

Subfield: Instrumentation

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $2,270

Funder: National Institute of Advanced Industrial Science and Technology