Integrated optoelectronic module
A beam generating device includes a semiconductor substrate, having an optical passband. A first array of vertical-cavity surface-emitting lasers (VCSELs) is formed on a first face of the semiconductor substrate and are configured to emit respective laser beams through the substrate at a wavelength within the passband. A second array of microlenses is formed on a second face of the semiconductor substrate in respective alignment with the VCSELs so as to transmit the laser beams generated by the VCSELs. The VCSELs are configured to be driven to emit the laser beams in predefined groups in order to change a characteristic of the laser beams.
1. A beam generating device, comprising:
a semiconductor substrate, having an optical passband;
a first array of vertical-cavity surface-emitting lasers (VCSELs), which are formed in respective locations on a first face of the semiconductor substrate and are configured to emit respective laser beams through the substrate at a wavelength within the passband; and
a second array of microlenses, which are formed on a second face of the semiconductor substrate in respective alignment with the VCSELs so as to transmit the laser beams generated by the VCSELs,
wherein the VCSELs are configured to be driven to emit the laser beams in predefined groups selected so that the device outputs beams of different diameters depending upon the group of the VCSELs that is driven, and
wherein the respective locations of at least some of the VCSELs are offset relative to respective centers of corresponding ones of the microlenses so as to control an angle of transmission of the respective laser beams.
2. The device according to claim 1 , wherein the respective locations of the at least some of the VCSELs are offset outwardly relative to the respective centers of the corresponding ones of the microlenses, so as to cause the respective laser beams to converge together.
3. The device according to claim 1 , wherein the substrate comprises GaAs.
4. The device according to claim 1 , wherein the semiconductor substrate has a thickness of 0.5 mm, and is transparent to wavelengths longer than 900 nm.
5. The device according to claim 1 , and comprising a lens, which is configured to collect the beams transmitted through the microlenses and direct the beams toward a target.
6. The device according to claim 1 , wherein the first and second arrays are configured in a hexagonal arrangement.
7. An optoelectronic module, comprising:
a micro-optical substrate;
a beam transmitter, mounted on the micro-optical substrate, and comprising:
a semiconductor substrate, having an optical passband;
a first array of surface-emitting devices, which are formed in respective locations on a first face of the semiconductor substrate and are configured to emit respective laser beams through the substrate at a wavelength within the passband; and
a second array of microlenses, which are formed on a second face of the semiconductor substrate in respective alignment with the surface-emitting devices so as to transmit the laser beams generated by the surface-emitting devices along a beam axis,
wherein the surface-emitting devices are configured to be driven to emit the beams in predefined groups selected so that the device outputs beams of different diameters depending upon the group of the surface-emitting devices that is driven, and
wherein the respective locations of at least some of the surface-emitting devices are offset relative to respective centers of corresponding ones of the microlenses so as to control an angle of transmission of the respective laser beams; and
a receiver, comprising a detector die mounted on the micro-optical substrate and configured to sense light received by the module along a collection axis of the receiver.
8. The module according to claim 7 , wherein the respective locations of the at least some of the surface-emitting devices are offset outwardly relative to the respective centers of the corresponding ones of the microlenses, so as to cause the respective beams to converge together.
9. The module according to claim 7 , and comprising beam-combining optics, which are configured to direct the beams and the received light so that the beam axis is aligned with the collection axis outside the module.
10. The module according to claim 9 , wherein the beam-combining optics comprise a beamsplitter, which is intercepted by both the beam axis and the collection axis.
11. The module according to claim 7 , wherein the laser beams and the received light are directed to impinge on a scanning mirror, wherein the mirror scans both the laser beams and a field of view of the receiver over a scene.
12. The module according to claim 7 , wherein the surface-emitting devices comprise vertical-cavity surface-emitting lasers (VCSELs).
13. The module according to claim 7 , wherein the receiver comprises an avalanche photodiode.
14. The module according to claim 7 , wherein the receiver comprises a two-dimensional matrix of photodetectors.
15. The module according to claim 7 , wherein the semiconductor substrate comprises GaAs.
16. The module according to claim 7 , wherein the semiconductor substrate has a thickness of 0.5 mm, and is transparent to wavelengths longer than 900 nm.