Granted Patent B2

US 12,613,316 · App. 17/534,047 · Granted Apr 28, 2026

Inventors: Vladimir Davydenko (Bad Herrenalb, DE); Geert Jozef Ivo Morthier (Ghent, BE)

Assignee: MicroVision, inc.

G01S7/4814G01J1/44G01S17/32G02F1/0147G02F1/212H01S5/0085H01S5/14G01J2001/444G02F2203/48

Abstract

Claims (23)

1 . A light source for a frequency-modulated continuous-wave (FMCW) LiDAR device, wherein the light source is formed by a photonic integrated circuit and comprises:

a substrate, a multilayer structure supported by the substrate, wherein at least the following functional elements are formed by the multilayer structure:

an input optical waveguide, an output optical waveguide and a cavity optical waveguide,

an optical splitter connecting the input optical waveguide both to the output optical waveguide and to the cavity optical waveguide,

a reflector connected to the cavity optical waveguide, and

a variable attenuator causing an attenuation of light guided in the cavity optical waveguide,

a semiconductor laser that is

received in a recess etched into the multilayer structure and

connected to the input optical waveguide such than an optical path extending between the semiconductor laser and the reflector and including the optical splitter forms an external cavity for the semiconductor laser,

a first electrical line connected to the semiconductor laser so as to supply the semiconductor laser with a varying operating current, wherein the semiconductor laser is configured to produce light having a frequency that varies synchronously with the supplied operating current,

a second electrical line connected to the variable attenuator so that the attenuation caused by the attenuator depends on electrical signals that are supplied to the variable attenuator via the second electrical line, and

an electronic control module configured to supply the variable attenuator with electrical signals so that the variable attenuator causes a constant attenuation that is determined on a basis of measurements of the performance of the light source such that a linewidth of the semiconductor laser has a minimum.

2 . The light source of claim 1 , wherein the variable attenuator comprises a Mach- Zehnder interferometer comprising two arms, wherein one of the arms comprises a thermally tunable phase portion.

3 . The light source of claim 1 , comprising a variable optical phase modulator acting on the cavity optical waveguide.

4 . The light source of claim 3 , wherein the variable optical phase modulator is configured to change the phase of the light at a change rate that depends on a change rate of the frequency of the light produced by the semiconductor laser.

5 . The light source of claim 3 , wherein the variable optical phase modulator is thermally tunable.

6 . The light source of claim 5 , wherein the variable optical phase modulator comprises a heating portion being part of the cavity optical waveguide and an electrical waveguide heater adjacent the heating portion, wherein the electrical waveguide heater comprises an electrical conductive element configured to produce heat when exposed to an electrical heating current.

7 . The light source of claim 6 , comprising a third electrical line connected to the waveguide heater so as to provide a heating current to the waveguide heater.

8 . The light source of claim 1 , wherein the cavity optical waveguide has a length between 5 mm and 100 mm.

9 . A frequency-modulated continuous-wave (FMCW) LiDAR device comprising the light source of claim 1 .

10 . The FMCW LiDAR device of claim 9 , wherein the electronic control module is connected to the first electric line and the second electric line.

11 . The FMCW LiDAR device of claim 10 , wherein the electronic control module is configured to vary the operating current supplied to the semiconductor laser via the first electrical line such that a magnitude of the current linearly increases or decreases during periodic measuring intervals.

12 . The FMCW LiDAR device of claim 10 , wherein the light source comprises a variable optical phase modulator acting on the cavity optical waveguide, and wherein the electronic control module is configured to control the optical phase modulator so as to produce a phase delay varying between 0 and 2πΔf· τext , wherein Δf is a frequency range within which the frequency of the light produced by the semiconductor laser varies, and wherein τext is a cavity roundtrip time required for the light to pass the optical path between the semiconductor laser and the reflector and back from the reflector to the semiconductor laser.

Assignments (2)

Priority Claims (1)

Continuity (1)

References Cited (20)