Optical phased array lidar system and method of using same
A lidar-based system and method are used for the solid state beamforming and steering of laser beams using optical phased array (OPA) photonic integrated circuits (PICs) and the detection of laser beams using photodetectors. Transmitter and receiver electronics, power management electronics, control electronics, data conversion electronics and processing electronics are also included in the system and used in the method. Laser pulses beamformed by the OPA PIC reflect from objects in the field of view (FOV) of said OPA, and are detected by a detector or a set of detectors. A lidar system includes at least one lidar, and any subset and any number of complementary sensors, data processing/communication/storage modules, and a balance of system for supplying power, protecting, connecting, and mounting the components of said system. Direct correlation between the 3D point cloud generated by the lidar and the color images captured by an RGB (Red, Green, Blue) video camera can be achieved by using an optical beam splitter that sends optical signals simultaneously to both sensors. A lidar system may contain a plurality of lidar sensors, a lidar sensor may contain a plurality of optical transmitters, and an optical transmitter may contain a plurality of OPA PICs.
1. An apparatus, comprising:
a transmitter to transmit out-of-plane light, wherein the out-of-plane light has specific phase delays that form a desired far-field radiation pattern through the interference of emitted beams;
a receiver with an optical intensity beam splitter used to split and send optical signals simultaneously to an optical receiver assembly of a lidar and a video camera for direct correlation between a three-dimensional point cloud generated by the far-field radiation pattern and color images captured by the video camera to form red, green, blue and depth data; and
a printed circuit board hosting the transmitter, the receiver and an optical phased array photonic integrated circuit of the lidar.
2. The apparatus of claim 1 wherein said far-field radiation pattern is swept to form a rastered line.
3. The apparatus of claim 1 wherein the receiver includes photodetector drivers connected to photodetectors.
4. The apparatus of claim 3 wherein the photodetectors are avalanche photodiodes.
5. The apparatus of claim 3 wherein the photodetectors are positive-intrinsic-negative diodes.
6. The apparatus of claim 3 wherein the photodetectors form a staring array.
7. The apparatus of claim 3 wherein the photodetectors form a staring-plane array.
8. The apparatus of claim 3 wherein the photodetectors form a focal-plane array.
9. The apparatus of claim 3 configured as a silicon on insulator structure.
10. The apparatus of claim 1 wherein the optical intensity beam splitter is a visible and near-infrared beam splitter.
11. The apparatus of claim 10 wherein the visible and near-infrared beam splitter is a plate beam splitter.
12. The apparatus of claim 10 wherein the visible and near-infrared beam splitter is a cube beam splitter.
13. The apparatus of claim 10 wherein the visible and near-infrared beam splitter is a prism beam splitter.
14. The apparatus of claim 10 wherein the visible and near-infrared beam splitter is a pellicle beam splitter.
15. The apparatus of claim 10 wherein the visible and near-infrared beam splitter is a partially-metallized mirror.