Silicon photonic chip, LiDAR, and mobile device
A silicon photonic chip, a LiDAR, and a mobile device are disclosed. The silicon photonic chip includes a cladding, a transceiving waveguide module, a first photoelectric detection module, and a first polarization rotator. An emitting waveguide of the transceiving waveguide module extends along a first direction and is configured to transmit and emit a detection light, and the first receiving waveguide of the transceiving waveguide module is arranged at intervals along a second direction from the emitting waveguide and is configured to receive and transmit an echo light. The first photoelectric detection module is configured to receive a first local oscillator light and the echo light output by the first receiving waveguide. The first polarization rotator is disposed upstream of the first photoelectric detection module.
1. A silicon photonic chip, comprising:
a cladding;
a transceiving waveguide module, embedded in the cladding and comprising an emitting waveguide and a first receiving waveguide, wherein the emitting waveguide extends along a first direction, the emitting waveguide is configured to transmit and emit a detection light for detecting a target object, and when viewed along a thickness direction of the silicon photonic chip, the first receiving waveguide is arranged at intervals with the emitting waveguide along a second direction, the first receiving waveguide is configured to receive and transmit an echo light, and the echo light is formed by the detection light being reflected by the target object;
a first photoelectric detection module, configured to receive a first local oscillator light and the echo light output by the first receiving waveguide; and
a first polarization rotator, disposed upstream of the first photoelectric detection module and configured to perform 90° polarization rotation on a precursor light and the echo light output by the first receiving waveguide, wherein the precursor light output by the first receiving waveguide is formed by a partial signal of the detection light being reflected by an emission end face of the emitting waveguide and/or an end face of the cladding, and entering the first receiving waveguide,
wherein any two of the first direction, the second direction, and the thickness direction are perpendicular to each other.
2. The silicon photonic chip according to claim 1 , wherein the transceiving waveguide module further comprises at least a second receiving waveguide;
wherein the emitting waveguide, the first receiving waveguide, and the second receiving waveguide are arranged at intervals along the second direction when viewed along the thickness direction, the second receiving waveguide is located on a side of the first receiving waveguide away from the emitting waveguide, and the second receiving waveguide is configured to receive and transmit the echo light; and
wherein the silicon photonic chip further comprises at least a second photoelectric detection module, each second photoelectric detection module corresponds to a second receiving waveguide, and each second photoelectric detection module is configured to receive a second local oscillator light and the echo light output by the second receiving waveguide.
3. The silicon photonic chip according to claim 2 , further comprising at least one second polarization rotator, each second polarization rotator is arranged corresponding to each second photoelectric detection module,
wherein the second polarization rotator is disposed upstream of a corresponding second photoelectric detection module, and is configured to perform 90° polarization rotation on a precursor light and the echo light output by a corresponding second receiving waveguide, wherein the precursor light output by the corresponding second receiving waveguide is formed by a partial signal of the detection light being reflected by the emission end face of the emitting waveguide and/or the end face of the cladding, and entering the corresponding second receiving waveguide.
4. The silicon photonic chip according to claim 3 , wherein the first polarization rotator is connected to the output end of the first receiving waveguide, and each second polarization rotator is connected to the output end of the corresponding second receiving waveguide.
5. The silicon photonic chip according to claim 1 , wherein the first photoelectric detection module comprises a first optical mixer and a first balanced photoelectric detector;
the first optical mixer is configured to receive the first local oscillator light and the echo light, and to perform frequency mixing to output a first beat frequency light signal and a second beat frequency light signal; and
the first balanced photoelectric detector is connected to the first optical mixer, and is configured to perform balanced detection on the first beat frequency light signal and the second beat frequency light signal.
6. A LIDAR, comprising:
a housing;
a light source module, configured to generate a source light signal;
a silicon photonic chip, accommodated in the housing, wherein the silicon photonic chip is the silicon photonic chip according to claim 1 , and is configured to transmit and emit the detection light for detecting a target object, wherein the detection light is a part of the source light signal, the silicon photonic chip is further configured to transmit the first local oscillator light and receive the echo light, and the first local oscillator light is a part of the source light signal.
7. The LiDAR according to claim 6 , comprising a quarter wave plate,
wherein the quarter wave plate is disposed on a side of the emitting waveguide for emitting the detection light and the receiving waveguide for receiving the echo light, and is configured to convert the detection light into an elliptical polarization state or a circular polarization state light signal.
8. A mobile device, comprising:
a movable substrate; and
a LiDAR, mounted on the substrate, wherein the LiDAR is the LiDAR according to claim 6 .