Compact and Low Power-Consumption Solid-State Two-Dimensional Beam Scanner Integrating a Passive Optical Phased Array and Hybrid Wavelength-Tunable Laser Diode

Large-scale optical phased arrays have attracted attention as devices for solid-state beam scanning employing light detection and ranging. However, conventional optical phased arrays using electro-optic phase shifters require active phase control for each antenna. Because the power consumption of the active phase shifters is proportional to the number of antennas, the total power consumption increases in a large-scale optical phased array with a narrow beam divergence. In this study, we propose a passive beam scanner that realizes two-dimensional beam scanning through the wavelength sweep of a laser light. Additionally, most studies on optical phased arrays use external laser diodes as light sources. This increases the size of the beam-scanning system. Therefore, there is a demand for integrating an optical phased array and a laser light source in a combined chip. In this study, we integrated a 64-channel passive optical phased array and a hybrid wavelength-tunable laser diode into a combined chip. The size of the device was 5 mm x 1.5 mm, and the power consumption for beam scanning was 49.3 mW. The field of view was 44.2 degrees x 13.7 degrees, and the full width at half maximum of the beam divergence was 0.517 degrees x 3.67 degrees. Compared with the device used in a previous study, our device was nine times smaller, and the total power consumption was only tens of milliwatts. This device consumes less power and achieves a fully integrated light detection and ranging.

Automated summary

In this study, a passive beam scanner was proposed to achieve two-dimensional beam scanning through wavelength sweep of a laser light. A 64-channel passive optical phased array and a hybrid wavelength-tunable laser diode were integrated into a combined chip, with a device size of 5mm x 1.5mm and power consumption of 49.3 mW. Compared with previous devices, it was nine times smaller in size and had a total power consumption of only tens of milliwatts. This device has lower power consumption and achieves fully integrated light detection and ranging.