Integrated optoelectronic modules with transmitter, receiver and beam-combining optics for aligning a beam axis with a collection axis

• US 9,157,790 B2
• Filed: 02/14/2013
• Issued: 10/13/2015
• Est. Priority Date: 02/15/2012
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Shpunt, Alexander, Mor, Zafrir, Erlich, Raviv
• Primary Examiner(s): LE, QUE TAN
• Application Number:
  US13/766,811
• Publication Number:
  US 20130206967A1
• Time in Patent Office: 971 Days
• Field of Search: 250/551, 250/216, 250/239, 250/227.11, 250/227.24, 250/227.25, 385/8, 385/9, 385/31, 385/33, 385 88- 93, 372/11, 372/12, 372/101
• US Class Current: 1/1
• CPC Class Codes: B23K 26/073 Shaping the laser spot
• CPC Class Codes: B23P 19/04 for assembling or disassembling parts
• CPC Class Codes: G01J 1/0411 using focussing or collimating elements, i.e. lenses or mirrors; Aberration correction
• CPC Class Codes: G01J 1/44 Electric circuits for command of an exposure part G03B7/02
• CPC Class Codes: G01J 2001/4466 Avalanche
• CPC Class Codes: G01S 17/10 using transmission of interrupted, pulse-modulated waves determination of distance by phase measurements G01S17/32
• CPC Class Codes: G01S 17/42 Simultaneous measurement of distance and other co-ordinates indirect measurement G01S17/46
• CPC Class Codes: G01S 17/89 for mapping or imaging
• CPC Class Codes: G01S 7/4812 transmitted and received beams following a coaxial path
• CPC Class Codes: G01S 7/4817 relating to scanning
• CPC Class Codes: G01S 7/4865 Time delay measurement, e.g. time-of-flight measurement, time of arrival measurement or determining the exact position of a peak peak detection in noise, signal conditioning G01S7/487
• CPC Class Codes: G01S 7/4868 Controlling received signal intensity or exposure of sensor
• CPC Class Codes: G02B 1/041 Lenses
• CPC Class Codes: G02B 27/0961 Lens arrays lens arrays per se G02B3/0006
• CPC Class Codes: G06F 3/011 Arrangements for interaction with the human body, e.g. for user immersion in virtual reality blind teaching G09B21/00
• CPC Class Codes: G06T 15/00 3D [Three Dimensional] image rendering
• CPC Class Codes: H01S 3/0071 Beam steering, e.g. whereby a mirror outside the cavity is present to change the beam direction
• CPC Class Codes: H01S 5/02253 using lenses
• CPC Class Codes: H01S 5/02257 using windows, e.g. specially adapted for back-reflecting light to a detector inside the housing
• CPC Class Codes: H01S 5/02325 Mechanically integrated components on mount members or optical micro-benches
• CPC Class Codes: H01S 5/18388 : Lenses
• CPC Class Codes: H01S 5/4012 : Beam combining, e.g. by the use of fibres, gratings, polarisers, prisms
• CPC Class Codes: H01S 5/4075 : Beam steering
• CPC Class Codes: H01S 5/4081 : Near-or far field control
• CPC Class Codes: H01S 5/423 : having a vertical cavity
• CPC Class Codes: Y10T 29/49002 : Electrical device making

Abstract

An optoelectronic module includes a micro-optical substrate and a beam transmitter, including a laser die mounted on the micro-optical substrate and configured to emit at least one laser beam along a beam axis. A receiver includes 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. Beam-combining optics are configured to direct the laser beam and the received light so that the beam axis is aligned with the collection axis outside the module.

Claims

1. An optoelectronic module, comprising:

a micro-optical substrate;

a beam transmitter, comprising a laser die mounted on the micro-optical substrate and configured to emit at least one laser beam along a beam axis;

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; and

beam-combining optics, which are configured to direct the laser beam and the received light so that the beam axis is aligned with the collection axis outside the module.

2. The module according to claim 1, wherein the beam-combining optics comprise a beamsplitter, which is intercepted by both the beam axis and the collection axis.

3. The module according to claim 2, wherein the beam axis and the collection axis are both perpendicular to the substrate, and wherein the beam-combining optics comprise a reflector, which is configured to deflect one of the beam axis and the collection axis toward the beamsplitter, so that the beam axis and the collection axis are incident on the beamsplitter at different, respective angles.

4. The module according to claim 3, wherein the beam-combining optics comprise a transparent plate having opposing, first and second surfaces, and wherein the beamsplitter is formed on the first surface, while the reflector is formed on the second surface.

5. The module according to claim 4, wherein the plate comprises a filter formed on one of the surfaces so as to exclude the received light that is outside an emission band of the beam transmitter.

6. The module according to claim 1, wherein the beam-combining optics comprise at least one lens, which is configured to collimate the at least one laser beam and to focus the received light onto the detector die.

7. The module according to claim 6, wherein the at least one lens comprises a bifocal lens, which is configured to collimate the at least one laser beam through a first aperture, and is configured to collect the received light through a second aperture, which is larger than the first aperture.

8. The module according to claim 1, wherein the laser die is an edge-emitting die, and wherein the module comprises a turning mirror, which is mounted on the substrate and is configured to reflect the at least one laser beam from the laser die so as to direct the laser beam away from the substrate.

9. The module according to claim 8, wherein a groove is formed in the substrate between the laser die and the turning mirror, and wherein the module comprises a ball lens, which is mounted in the groove and is configured to collimate the at least one laser beam.

10. The module according to claim 9, wherein the beam transmitter comprises a beam expander, which is configured to collect and expand the at least one laser beam after reflection from the turning mirror.

11. The module according to claim 8, and comprising a lens, which is mounted over the substrate so as to collimate the at least one laser beam after reflection from the turning mirror, wherein the lens has a focal length, which is measured prior to assembly of the laser die on the substrate, and wherein a distance of the laser die from the turning mirror on the substrate is adjusted responsively to the measured focal length.

12. The module according to claim 1, wherein the laser die comprises a first array of vertical-cavity surface-emitting lasers (VCSELs), and wherein the beam transmitter comprises a second array of microlenses, which are respectively aligned with the VCSELs so as to transmit respective laser beams generated by the VCSELs.

13. The module according to claim 12, wherein the VCSELs are offset inwardly relative to the microlenses, so as to cause the respective laser beams to spread apart.

14. The module according to claim 12, wherein the VCSELs are offset outwardly relative to the microlenses, so as to cause the respective laser beams to converge together to a focal waist.

15. The module according to claim 12, wherein the VCSELs and the microlenses are formed on opposing sides of an optical substrate.

16. The module according to claim 15, wherein the optical substrate comprises a semiconductor wafer, which is transparent at an emission wavelength of the VCSELs.

17. The module according to claim 1, wherein the at least one laser beam and the received light are directed to impinge on a scanning mirror outside the module, wherein the mirror scans both the at least one laser beam and a field of view of the receiver over a scene.

18. A method for producing an optoelectronic module, the method comprising:

mounting a beam transmitter, comprising a laser die configured to emit at least one laser beam along a beam axis, on a micro-optical substrate;

mounting a receiver, comprising a detector die configured to sense light received by the module along a collection axis of the receiver, on the micro-optical substrate; and

positioning beam-combining optics with respect to the micro-optical substrate so as to direct the laser beam and the received light so that the beam axis is aligned with the collection axis outside the module.

19. The method according to claim 18, wherein positioning the beam-combining optics comprises mounting a beamsplitter so that both the beam axis and the collection axis intercept the beamsplitter.

20. The method according to claim 19, wherein the beam axis and the collection axis are both perpendicular to the substrate, and wherein positioning the beam-combining optics comprises mounting a reflector so as to deflect one of the beam axis and the collection axis toward the beamsplitter, so that the beam axis and the collection axis are incident on the beamsplitter at different, respective angles.

21. The method according to claim 20, wherein positioning the beam-combining optics comprises mounting a transparent plate, having opposing, first and second surfaces, over the substrate, wherein the beamsplitter is formed on the first surface, while the reflector is formed on the second surface.

22. The method according to claim 21, wherein positioning the beam-combining optics comprises filtering the received light using a filter formed on one of the surfaces of the plate so as to exclude the received light that is outside an emission band of the beam transmitter.

23. The method according to claim 18, wherein positioning the beam-combining optics comprises mounting at least one lens over the substrate so as to collimate the at least one laser beam and to focus the received light onto the detector die.

24. The method according to claim 23, wherein the at least one lens comprises a bifocal lens, which collimates the at least one laser beam through a first aperture, and collects the received light through a second aperture, which is larger than the first aperture.

25. The method according to claim 18, wherein the laser die is an edge-emitting die, and wherein the method comprises mounting a turning mirror on the substrate to reflect the at least one laser beam from the laser die so as to direct the laser beam away from the substrate.

26. The method according to claim 25, and comprising forming a groove in the substrate between the laser die and the turning mirror, and mounting a ball lens in the groove so as to collimate the at least one laser beam.

27. The method according to claim 26, wherein the beam transmitter comprises a beam expander, which is configured to collect and expand the at least one laser beam after reflection from the turning mirror.

28. The method according to claim 25, and comprising:

mounting a lens over the substrate so as to collimate the at least one laser beam after reflection from the turning mirror; and

measuring a focal length of the lens prior to assembly of the laser die on the substrate,

wherein mounting the beam transmitter comprises adjusting a distance of the laser die from the turning mirror on the substrate responsively to the measured focal length.

29. The method according to claim 18, wherein the laser die comprises a first array of vertical-cavity surface-emitting lasers (VCSELs), and wherein mounting the beam transmitter comprises aligning a second array of microlenses with the VCSELs so that the microlenses transmit respective laser beams generated by the VCSELs.

30. The method according to claim 29, wherein mounting the beam transmitter comprises offsetting the VCSELs inwardly relative to the microlenses, so as to cause the respective laser beams to spread apart.

31. The method according to claim 29, wherein mounting the beam transmitter comprises offsetting the VCSELs outwardly relative to the microlenses, so as to cause the respective laser beams to converge together to a focal waist.

32. The method according to claim 29, wherein aligning the second array comprises forming the VCSELs and the microlenses on opposing faces of an optical substrate.

33. The method according to claim 32, wherein the optical substrate comprises a semiconductor wafer, which is transparent at an emission wavelength of the VCSELs.

34. The method according to claim 18, and comprising directing the at least one laser beam and the received light to impinge on a scanning mirror outside the module, wherein the mirror scans both the at least one laser beam and a field of view of the receiver over a scene.