End-fire optical phased array for passive beam steering on thin-film lithium niobate.

Autonomous driving technology has put forward higher requirements for sensors, including light detection and ranging. An optical phased array (OPA) is a viable solution, and numerous efforts have been made in this area. For its outstanding optical properties such as linear electro-optic effect and low optical loss, lithium niobate exhibits great potential and unique advantages in solid-state light-emitting arrays.

Large quality factor enhancement based on cascaded uniform lithium niobate bichromatic photonic crystal cavities.

In this Letter, by cascading several bichromatic photonic crystals we demonstrate that the quality factor can be much larger compared with that in an isolated cavity without increasing the total size of a device. We take a lithium niobate photonic crystal as an example to illustrate that the simulated quality factor of the cascaded cavity can reach 10 with a 70° slant angle, which is an order of magnitude larger than that in an isolated cavity. The device can be fabricated easily by current etching techniques for lithium niobate.