US Patent 10310085 Photonic integrated distance measuring pixel and method of distance measurement

A distance-measuring pixel apparatus includes a photonic integrated circuit disposed on a common substrate that further includes a photonic integrated circuit substrate having disposed thereon two 3 dB directional couplers, a GRIN lens, and a partially reflecting Faraday mirror having a first side that is optomechanically coupled to a second side of the GRIN lens; and a source laser, a first photodetector, and a second photodetector. A related distance measuring method includes, using the distance-measuring pixel apparatus, generating a local oscillator (LO) beam, generating an echo, combining the LO beam and the echo beam, splitting the combined LO beam and the echo beam, and producing a modulation of the photodetector assembly photocurrent at a frequency that encodes the distance of a remote object.