Methods and systems for optical beam steering

A method of optical beam steering with a plurality of waveguides, a planar dielectric lens, and an output coupler formed on a substrate, the method comprising:

• guiding light with a first waveguide in the plurality of waveguides to the planar dielectric lens;
• collimating the light emitted by the first waveguide with the planar dielectric lens in a first direction within a plane of the substrate at an angle in the plane of the substrate determined by a position the first waveguide in the plane of the substrate;
• and
• coupling at least a portion of the light out of the plane of the substrate at an angle with the plane of the substrate determined by a wavelength of the light.

A lidar comprising:

• a tunable light source to emit a beam of light;
• N waveguides, where N is a positive integer;
• log2 N optical switches, in optical communication with the tunable light source, to guide the beam of light to a waveguide in the N waveguides;
• a planar dielectric lens, in optical communication with the plurality of waveguides, to collimate the beam of light emitted by the waveguide as a collimated beam propagating in a first direction in a plane of the planar dielectric lens;
• and
• a periodic structure, in optical communication with the planar dielectric lens, to diffract at least a portion of the collimated beam at an angle with respect to the plane of the planar dielectric lens.