Quantum mechanics

Phased-array optics

Beam (structure)

Materials science

Holography

Apodization

Telecommunications

Power (physics)

Computer science

Antenna (radio)

Beam diameter

Photonics

Duty cycle

Laser

Physics

Beam divergence

Laser beams

Optics

Grating

Beam steering

Diffraction efficiency

Silicon photonics

Diffraction grating

Phased array

Optoelectronics

Optics Express

Current silicon photonics phased arrays based on waveguide gratings enable beam steering with no moving parts. However, they suffer from a trade-off between beam divergence and field of view. Here, we show a platform based on silicon-nitride/silicon that achieves simultaneously minimal beam divergence and maximum field of view while maintaining performance that is robust to fabrication variations. In addition, in order to maximize the emission from the entire length of the grating, we design the grating's strength by varying its duty cycle (apodization) to emit uniformly. We fabricate a millimeter long grating emitter with diffraction-limited beam divergence of 0.089°.

On-chip platform for a phased array with minimal beam divergence and wide field-of-view