LIDAR transmitter and receiver optics
The present disclosure relates to optical systems and related methods of their use. An example optical system includes a transmitter. The transmitter includes a light emitter device configured to emit emission light. The light emitter device defines a reference plane. The transmitter also includes a fast axis collimation (FAC) lens optically coupled to the light emitter device. A lens axis of the FAC lens is arranged at a non-zero angle with respect to the reference plane. The transmitter also includes a transmit lens optically coupled to the FAC lens. The optical system also includes a receiver. The receiver includes a receive lens and a light detector optically coupled to the receive lens.
1. A lidar system comprising:
a transmitter comprising:
a light emitter device configured to emit emission light, wherein a surface of the light emitter device which emits the emission light defines a reference plane;
a fast axis collimation (FAC) lens optically coupled to the light emitter device, wherein a cylindrical axis of the FAC lens is at a non-zero angle with respect to the reference plane; and
a transmit lens optically coupled to the FAC lens; and
a receiver comprising:
a receive lens; and
a light detector optically coupled to the receive lens.
2. The lidar system of claim 1 , wherein the FAC lens comprises a cylindrical lens.
3. The lidar system of claim 1 , wherein the FAC lens comprises an acylindrical lens.
4. The lidar system of claim 1 , wherein the light emitter device comprises a laser diode bar.
5. The lidar system of claim 4 , wherein an end facet of the laser diode bar defines a facet plane, wherein a fast axis of the FAC lens is not parallel to the facet plane.
6. The lidar system of claim 5 , wherein the fast axis of the FAC lens forms a pitch angle between 0 degrees and 0.5 degrees with respect to the facet plane.
7. The lidar system of claim 5 , wherein the fast axis of the FAC lens forms a pitch angle between 0.5 degrees and 20 degrees with respect to the facet plane.
8. The lidar system of claim 4 , wherein an end facet of the laser diode bar defines a facet plane, wherein a back plane of the FAC lens is not parallel to the facet plane.
9. The lidar system of claim 8 , wherein the back plane of the FAC lens forms a yaw angle between 0 degrees and 0.5 degrees with respect to the facet plane.
10. The lidar system of claim 8 , wherein the back plane of the FAC lens forms a yaw angle between five degrees and twenty degrees with respect to the facet plane.
11. The lidar system of claim 1 , wherein the non-zero angle is configured to center a beam profile of the emission light at the transmit lens.
12. The lidar system of claim 1 , wherein the FAC lens is fixed with respect to the light emitter device with at least one of: an adhesive, a curable epoxy, or a clamp.
13. The lidar system of claim 1 , wherein the light detector comprises a light detection area having a light detection area shape, wherein the receive lens has a shape that corresponds to the light detection area shape.
14. The lidar system of claim 13 , wherein the light detection area shape is square or rectangular, wherein the receive lens has a square or rectangular shape, and wherein the transmit lens has a square or rectangular shape.
15. The lidar system of claim 1 , wherein the light detector comprises at least one of: a silicon photomultiplier (SiPM) device, a single photon avalanche photodiode (SPAD), an avalanche photodiode (APD), or a multi-pixel photon counter (MPPC).
16. A vehicle comprising:
an optical system comprising:
a transmitter, wherein the transmitter comprises:
a light emitter device configured to emit emission light, wherein a surface of the light emitter device which emits the emission light defines a reference plane;
a fast axis collimation (FAC) lens optically coupled to the light emitter device, wherein a cylindrical axis of the FAC lens is at a non-zero angle with respect to the reference plane; and
a transmit lens optically coupled to the FAC lens; and
a receiver, wherein the receiver comprises:
a receive lens; and
a light detector optically coupled to the receive lens.
17. The vehicle of claim 16 , wherein the FAC lens comprises a cylindrical lens.
18. The vehicle of claim 16 , wherein the FAC lens comprises an acylindrical lens.
19. The vehicle of claim 16 , wherein the light emitter device comprises a laser diode bar.
20. The vehicle of claim 16 , wherein an end facet of the laser diode bar defines a facet plane, wherein a back plane of the FAC lens is not parallel to the facet plane.