Monolithic integration of a tunable laser with a millimeter-scale surface emitting grating enabling high-resolution...

Optical beam steering using photonic integrated circuits plays a vital role in enabling solid-state LiDAR systems and optical wireless communication systems. In this paper, we present a widely tunable laser on a generic InP platform integrated monolithically with a millimeter-scale grating antenna, which enables both high-resolution beamforming and dispersive beam steering with a line-shaped optical beam. Leveraging the low confinement structure of micrometer-scale InP waveguides, a low-contrast grating antenna with a length of 2 mm is implemented to outcouple an optical beam with angular divergence as low as 0.044°. The laser shows a wavelength tuning range of 71 nm, enabling a wide beam steering field of view of 9.6°. The measured free-space laser beams exhibit power levels exceeding 1.1 mW and sidelobe suppression ratios (SLSR) greater than 5.5 dB.