Coherent LIDAR system including optical antenna array
A light detection and ranging (LIDAR) transceiver includes optical antenna arrays and an optical switch. Some of the optical antenna arrays include a number of optical antennas and an optical splitter coupled to the optical antennas. The optical splitter may include a number of passive optical splitters. The optical splitter provides a portion of an input signal to the optical antennas. The optical switch is configured to selectively provide the input signal to at least one of the plurality of optical antenna arrays. The optical switch enables addressable field of view scanning by selectively providing the input signal to the plurality of antenna arrays, one array at a time.
1. A light detection and ranging (LIDAR) sensor system comprising:
a transceiver configured to receive a transmit signal, wherein the transceiver includes:
a plurality of optical antenna arrays; and
an active optical switch comprising an input configured to receive the transmit signal and a particular number of output channels respectively coupled to the plurality of optical antenna arrays, wherein the active optical switch is configured to selectively provide the transmit signal to the plurality of optical antenna arrays by coupling the transmit signal to at least one selected optical antenna array of the plurality of optical antenna arrays one at a time over a scanning period of the transceiver; and
wherein at least three of the plurality of optical antenna arrays respectively include:
a particular number of optical antennas arranged in a two-dimensional configuration; and
an optical splitter coupled to the particular number of optical antennas and configured to individually provide the transmit signal to each of the particular number of optical antennas, wherein the optical splitter is configured to receive the transmit signal from an output channel of the particular number of output channels of the active optical switch, and wherein the optical splitter comprises a plurality of passive optical splitters configured to evenly distribute the transmit signal to a particular number of communication channels corresponding to the particular number of optical antennas.
2. The LIDAR sensor system of claim 1 , wherein the particular number of optical antennas corresponds to a particular number of coherent pixels, a respective coherent pixel of the particular number of coherent pixels configured to respectively provide a transmit signal to a respective optical antenna of the particular number of optical antennas and to receive return signals from the respective optical antenna.
3. The LIDAR sensor system of claim 1 , wherein the optical splitter is configured to enable concurrent transmission of the transmit signal to the particular number of communication channels and from the particular number of optical antennas in the at least one selected optical antenna array.
4. The LIDAR sensor system of claim 3 , further comprising an additional optical splitter configured to receive an input signal, wherein the additional optical splitter is configured to split the input signal into the transmit signal and a local oscillator signal.
5. The LIDAR sensor system of claim 4 , wherein:
the input signal is a modulated laser signal; and
the active optical switch includes an active optical splitter that selectively couples the modulated laser signal to only one at a time of the plurality of optical antenna arrays.
6. The LIDAR sensor system of claim 4 , wherein:
the input signal is a frequency modulated continuous wave (FMCW) laser signal; and
the active optical switch includes an active optical splitter that selectively couples the FMCW laser signal to only one at a time of the plurality of optical antenna arrays.
7. The LIDAR sensor system of claim 4 , further comprising a local oscillator network coupled to the additional optical splitter and configured to receive the local oscillator signal from the additional optical splitter, wherein the local oscillator network is configured to selectively split the local oscillator signal into a plurality of local oscillator signals for the plurality of optical antenna arrays.
8. The LIDAR sensor system of claim 7 , wherein the local oscillator network comprises:
a plurality of optical splitters configured to provide the plurality of local oscillator signals to the plurality of optical antenna arrays; and
an additional optical switch coupled to the plurality of optical splitters and configured to selectively provide a portion of the local oscillator signal to at least one of the plurality of optical splitters of the local oscillator network.
9. The LIDAR sensor system of claim 7 , further comprising an optical combiner coupled to at least one of the particular number of optical antennas to receive a return signal, wherein the optical combiner is configured to combine the return signal with the local oscillator signal and to provide a combined output signal.
10. The LIDAR sensor system of claim 9 , wherein a respective pixel corresponding to an optical antenna of the particular number of optical antennas includes a plurality of photo-diodes configured to convert the combined output signal into electrical signals representative of a LIDAR beat tone.
11. The LIDAR sensor system of claim 3 , wherein the active optical switch is configured to optically couple the transmit signal to at least one of the plurality of optical antenna arrays one at a time over a scanning period of the transceiver to illuminate one or more particular portions of a scene in a field of view of the LIDAR sensor system.
12. The LIDAR sensor system of claim 1 , wherein the active optical switch includes at least one of: a binary tree switch, an array of micro-ring resonators, and an array of micro-electromechanical system (MEMS) switches.
13. The LIDAR sensor system of claim 1 , wherein the at least three of the plurality of optical antenna arrays include an output signal bus, wherein the particular number of optical antennas of a first of the plurality of optical antenna arrays shares the output signal bus with a second of the plurality of optical antenna arrays.
14. The LIDAR sensor system of claim 13 , wherein the output signal bus includes electrical signal lines for an in-phase signal and a quadrature signal from each of the particular number of optical antennas.
15. An integrated chip for a light detection and ranging (LIDAR) sensor, the integrated chip comprising:
a light source that is configured to generate an input signal;
an optical splitter configured to receive the input signal, wherein the optical splitter is configured to split the input signal into a transmit signal and a local oscillator signal;
a transceiver coupled to the optical splitter to receive the transmit signal, wherein the transceiver includes:
a plurality of optical antenna arrays, and
an active optical switch comprising an input configured to receive the transmit signal and a particular number of output channels respectively coupled to the plurality of optical antenna arrays, wherein the active optical switch is configured to selectively provide the transmit signal to the plurality of optical antenna arrays by coupling the transmit signal to at least one selected optical antenna array of the plurality of optical antenna arrays one at a time over a scanning period of the transceiver, and
wherein at least three of the plurality of optical antenna arrays respectively include:
a particular number of optical antennas arranged in a two-dimensional configuration; and
an optical splitter coupled to the particular number of optical antennas and configured to individually provide the transmit signal to each of the particular number of optical antennas, wherein the optical splitter is configured to receive the transmit signal from an output channel of the particular number of output channels of the active optical switch, and wherein the optical splitter comprises a plurality of passive optical splitters configured to evenly distribute the transmit signal to a particular number of communication channels corresponding to the particular number of optical antennas.
16. The LIDAR sensor chip of claim 15 , further comprising a lens, wherein the transceiver is optically coupled to the lens to scan blocks of a field of view of the lens.
17. The LIDAR sensor chip of claim 15 , further comprising a processing engine configured to receive LIDAR return signals from the transceiver and configured to generate frames of LIDAR data based on the LIDAR return signals.
18. An autonomous vehicle comprising:
a light detection and ranging (LIDAR) sensor that includes:
a light source that is configured to generate an input signal;
an optical splitter configured to receive the input signal, wherein the optical splitter is configured to split the input signal into a transmit signal and a local oscillator signal; and
a transceiver configured to receive a transmit signal, wherein the transceiver includes:
a plurality of optical antenna arrays, and
an active optical switch comprising an input configured to receive the transmit signal and a particular number of output channels respectively coupled to the plurality of optical antenna arrays, wherein the active optical switch is configured to selectively provide the transmit signal to the plurality of optical antenna arrays by coupling the transmit signal to at least one selected optical antenna array of the plurality of optical antenna arrays one at a time over a scanning period of the transceiver; and
wherein at least three of the plurality of optical antenna arrays respectively include:
a particular number of optical antennas arranged in a two-dimensional configuration; and
an optical splitter coupled to the particular number of optical antennas and configured to individually provide the transmit signal to each of the particular number of optical antennas, wherein the optical splitter is configured to receive the transmit signal from an output channel of the particular number of output channels of the active optical switch, and wherein the optical splitter comprises a plurality of passive optical splitters configured to evenly distribute the transmit signal to a particular number of communication channels corresponding to the particular number of optical antennas.
19. The autonomous vehicle of claim 18 , the LIDAR sensor further including a lens, wherein the transceiver is optically coupled to the lens to provide horizon scanning of blocks of an operational environment of the autonomous vehicle.
20. The autonomous vehicle of claim 18 , further comprising a processing engine configured to receive LIDAR return signals from the transceiver and configured to generate a point cloud representation of an operational environment of the autonomous vehicle at least partially based on the LIDAR return signals.