US Patent 11763472 Depth mapping with MPI mitigation using reference illumination pattern

Apparatus for optical sensing includes an illumination assembly, which directs first optical radiation toward a target scene over a first range of angles and second optical radiation over at least one second range of angles, which is smaller than and contained within the first range, while modulating the optical radiation with a carrier wave having at least one predetermined carrier frequency. A detection assembly includes an array of sensing elements, which output respective signals in response to the first and the second optical radiation. Processing circuitry drives the illumination assembly to direct the first and the second optical radiation toward the target scene in alternation, and processes the signals output by the sensing elements in response to the first optical radiation in order to compute depth coordinates of points in the target scene, while correcting the computed depth coordinates in response to the second optical radiation.