Laser source, light emitting unit, and lidar
A laser source, a light emitting unit, and a lidar are provided. The light emitting unit is used in the lidar, and the light emitting unit includes: a first light emitting region and a second light emitting region. Sizes of the first light emitting region and the second light emitting region are different. The first light emitting region and the second light emitting region form the same light emitting channel, and respectively detect target objects at different distances, thereby reducing emission power of the light emitting unit.
1 . A laser source of a lidar including a plurality of light emitting channels, comprising:
at least two light emitting regions: a first light emitting region and a second light emitting region, both light emitting regions being disposed on a same light emitting surface and being included in a same light emitting channel of the lidar,
wherein sizes of the at least two light emitting regions are different,
wherein the first light emitting region is configured to emit a first light beam toward a first detection region, and the second light emitting region is configured to emit a second light beam toward a second detection region representing a blind region of the first light emitting region, the blind region being located at a distance from the laser source shorter than that of the first detection region.
2 . The laser source according to claim 1 , wherein the at least two light emitting regions share a same activation signal and are simultaneously driven to emit light.
3 . The laser source according to claim 1 , wherein the second light emitting region includes a reduced quantity of lasers than the first light emitting region and emits a reduced power of light relative to the first light emitting region.
4 . The laser source according to claim 1 , wherein each of the light emitting regions comprises one or more vertical-cavity surface-emitting lasers.
5 . The laser source according to claim 4 , wherein a plurality of vertical-cavity surface-emitting lasers are arranged into a circle in at least one light emitting region.
6 . The laser source according to claim 4 , wherein a plurality of vertical-cavity surface-emitting lasers are arranged into a rectangle in at least one light emitting region.
7 . A light emitting unit for a lidar, comprising:
a first light emitting region; and a second light emitting region, both light emitting regions being disposed on a same light emitting surface;
wherein sizes of the first light emitting region and the second light emitting region are different, and the first light emitting region and the second light emitting region form a same light emitting channel;
wherein the first light emitting region is configured to emit a first light beam toward a first detection region, and the second light emitting region is configured to emit a second light beam toward a second detection region representing a blind region of the first light emitting region, the blind region being located at a distance from the laser source shorter than the first detection region; and
wherein the first light emitting region and the second light emitting region detect target objects at different distances, respectively.
8 . The light emitting unit according to claim 7 , wherein the second light emitting region is farther from a light receiving unit of the lidar than the first light emitting region.
9 . The light emitting unit according to claim 8 , wherein the first light emitting region represents a circular light emitting region.
10 . The light emitting unit according to claim 7 , wherein the second light emitting region represents a rectangular light emitting region.
11 . The light emitting unit according to claim 9 , wherein the circular light emitting region comprises a plurality of vertical-cavity surface-emitting lasers, wherein the plurality of vertical-cavity surface-emitting lasers are arranged in a honeycomb array in the circular light emitting region.
12 . The light emitting unit according to claim 10 , wherein the second light emitting region comprises one or more vertical-cavity surface-emitting lasers, wherein the plurality of vertical-cavity surface-emitting lasers are in a matrix arrangement or staggered arrangement.
13 . The light emitting unit according to claim 9 , wherein a diameter of the circular light emitting region is in a range of 200 microns to 300 microns.
14 . The light emitting unit according to claim 8 , wherein the light emitting unit comprises a first end near the light receiving unit and a second end away from the light receiving unit, a direction from the first end to the second end represents a first direction, the light emitting unit comprises a light emitting surface, and a direction in the light emitting surface that is perpendicular to the first direction represents a second direction; and
wherein a size of the second light emitting region in the second direction is smaller than a size of the first light emitting region in the second direction.
15 . The light emitting unit according to claim 14 , wherein a size of the second light emitting region in the first direction is in a range of 50 microns to 100 microns, and the size of the second light emitting region in the second direction is in a range of 50 microns to 100 microns.
16 . The light emitting unit according to claim 9 , wherein light emitted by the circular light emitting region is reflected by a target object at a longest detection range of the lidar, a light spot formed on the receiving unit is received by the receiving unit, and a size of the light spot is not greater than a size of the receiving unit.
17 . The light emitting unit according to claim 7 , wherein a spacing between centers of the first light emitting region and the second light emitting region is in a range of 150 microns to 200 microns.
18 . A lidar, comprising:
the light emitting unit according to claim 7 , configured to provide emission light; and
at least one light receiving unit, corresponding to the light emitting unit, and configured to detect an echo light formed after the emission light is reflected by a target object.
19 . The lidar according to claim 18 , wherein the light receiving unit comprises a photosensitive surface, wherein the photosensitive surface represents a circular surface.
20 . The lidar according to claim 18 , wherein the light receiving unit includes a silicon photomultiplier or a single-photon avalanche diode array.
21 . The lidar according to claim 19 , wherein the light receiving unit is arranged in the following manner: a center of the circular surface coincides with a center of a light spot formed by reflection of a beam which is emitted by the first light emitting region and reflected by a target object at a longest detection range of the lidar, and wherein a size of the photosensitive surface is not less than a size of the light spot.
22 . The lidar according to claim 18 , further comprising:
a first optical assembly, located downstream of an optical path of the light emitting unit, and configured to shape the light emitted by the light emitting unit and then emit the shaped light; and a second optical assembly, located upstream of the optical path of the light receiving unit, and configured to focus the echo light onto the light receiving unit.
23 . The lidar according to claim 22 , wherein the emission light of the first light emitting region and the second light emitting region is shaped into a beam of light to be emitted through the first optical assembly.
24 . The lidar according to claim 22 , further comprising:
an aperture stop, located between the second optical assembly and the light receiving unit and at a focal plane of the second optical assembly.