Integrated edge-generated vertical emission laser

Patent metadata

Field	Value
Publication number	US-12206222-B2
Application number	US-202117407016-A
Country	US
Kind code	B2
Filing date	Aug 19, 2021
Priority date	Aug 20, 2020
Publication date	Jan 21, 2025
Grant date	Jan 21, 2025

Abstract

Configurations for an edge-generated vertical emission laser that vertically emits light and fabrication methods of the edge-generated vertical emission laser are disclosed. The edge-generated vertical emission laser may include a distributed feedback (DFB) laser structure, a grating coupler, and contact layers. Light may propagate through the DFB laser structure, approximately parallel to the top surface of the edge-generated vertical emission laser and be directed by the grating coupler toward the top surface of the edge-generated vertical emission laser. The light may vertically emit from the edge-generated vertical emission laser approximately perpendicular to the top surface of the edge-generated vertical emission laser. Additionally, the contact layers may be n-metal and p-metal, which may be located on the same side of the edge-generated vertical emission laser. These features of the edge-generated vertical emission laser may facilitate ease of testing and increased options for packaging.

First claim

What is claimed is:

1. An edge-generated vertical emission laser that vertically emits light, comprising:
a distributed feedback (DFB) laser structure configured to generate light that propagates parallel to a top surface of the edge-generated vertical emission laser;
a grating coupler, configured to receive the generated light from the DFB laser structure and direct the generated light toward the top surface of the edge-generated vertical emission laser that is perpendicular to the top surface of the edge-generated vertical emission laser;
a passivation layer deposited on a surface of the DFB laser structure;
an optical element formed in the passivation layer and configured to allow light to emit from the top surface of the edge-generated vertical emission laser; and
a metal contact on a bottom surface of the edge-generated vertical emission laser, the bottom surface opposite the top surface of the edge-generated vertical emission laser.

2. The edge-generated vertical emission laser that vertically emits light of claim 1 , wherein:
the metal contact comprises:
an n-metal contact on the bottom surface of the edge-generated vertical emission laser; and
a p-metal contact on the bottom surface of the edge-generated vertical emission laser;

the optical element is a collimating and light directing optical element; and
the edge-generated vertical emission laser further comprises an anti-reflective coating on the optical element.

3. The edge-generated vertical emission laser that vertically emits light of claim 1 , wherein:
the optical element comprises an integrated microlens array; and
the edge-generated vertical emission laser further comprises an anti-reflective coating disposed on the integrated microlens array.

4. The edge-generated vertical emission laser that vertically emits light of claim 1 , wherein the grating coupler is a high contrast grating configured to direct light to the top surface of the edge-generated vertical emission laser.

5. The edge-generated vertical emission laser that vertically emits light of claim 1 , wherein:
the metal contact comprises:
an n-metal contact; and
a p-metal contact; wherein:
the n-metal contact and p-metal contact are both on the bottom surface of the edge-generated vertical emission laser, thereby providing electrical contact on one side of the edge-generated vertical emission laser.

6. The edge-generated vertical emission laser that vertically emits light of claim 1 , wherein the grating coupler is a time parity grating coupler operative to direct light to the top surface of the edge-generated vertical emission laser.

7. The edge-generated vertical emission laser that vertically emits light of claim 6 , further comprising:
a back facet of the DFB laser structure; and
a high reflectivity material positioned at the back facet of the DFB laser structure.

8. The edge-generated vertical emission laser that vertically emits light of claim 1 , wherein the grating coupler is a second order grating.

9. The edge-generated vertical emission laser that vertically emits light of claim 1 , wherein the metal contact is operative to redirect light propagating toward the bottom surface of the edge-generated vertical emission laser to the top surface of the edge-generated vertical emission laser.

10. The edge-generated vertical emission laser that vertically emits light of claim 1 , further comprising:
a back facet of the DFB laser structure coated with an anti-reflective material; and a high reflectivity material positioned at the back facet of the DFB laser structure.

11. A method for providing vertically emitting light using an edge-generated vertical emission laser, comprising:
generating light in a distributed feedback (DFB) laser structure that propagates parallel to a top surface of the edge-generated vertical emission laser and within the DFB laser structure;
directing, using a grating coupler that is part of the edge-generated vertical emission laser, light from the DFB laser structure toward an optical element formed in a passivation layer, wherein the passivation layer is deposited on the top surface of the edge-generated vertical emission laser; and
emitting light perpendicular to an active region of the DFB laser structure and from the top surface of the edge-generated vertical emission laser.

12. The method of claim 11 , wherein the optical element comprises diffractive optics and further comprising:
providing a p-metal contact on a bottom surface of the edge-generated vertical emission laser;
providing an n-metal contact on the bottom surface of the edge-generated vertical emission laser;
reflecting, via a high-reflectivity material, light from a back facet of the DFB laser structure; and
steering the emitted light using the diffractive optics at the top surface of the edge-generated vertical emission laser.

13. The method of claim 11 , further comprising:
emitting a predetermined amount of light from a back facet of the DFB laser structure of the edge-generated vertical emission laser;
detecting the emitted predetermined amount of light using a photodetector; and
monitoring properties of the emitted predetermined amount of light using the photodetector.

14. The method of claim 11 , further comprising:
directing the light emitted from the top surface of the edge-generated vertical emission laser using a bonded microlens array.

15. The method of claim 11 , further comprising:
providing a p-metal contact on a bottom surface of the edge-generated vertical emission laser;
providing an n-metal contact on the bottom surface of the edge-generated vertical emission laser; and
redirecting the generated light propagating toward the bottom surface of the edge-generated vertical emission laser back to the top surface of the edge-generated vertical emission laser.

16. An edge-generated vertical emission laser, comprising:
a distributed feedback (DFB) laser structure configured to generate light;
a waveguide operative to propagate the generated light parallel to a top surface of the edge-generated vertical emission laser;
a passivation layer is deposited on a surface of the DFB laser structure;
a grating coupler that is part of the edge-generated vertical emission laser, operative to reflect the generated light toward a top surface of the edge-generated vertical emission laser such that the light is emitted perpendicular to the top surface of the edge-generated vertical emission laser;
a diffraction based collimating optical element is in a passivation layer positioned to receive the generated light from the grating coupler; and
a metal contact on a bottom surface of the edge-generated vertical emission laser, the bottom surface opposite the top surface of the edge-generated vertical emission laser.

17. The edge-generated vertical emission laser of claim 16 , wherein:
the metal contact is an n-metal contact; and
the edge-generated vertical emission laser further comprises:
a p-metal contact on a same side of the edge-generated vertical emission laser as the n-metal contact;
and
an anti-reflective coating disposed on the diffraction based collimating optical element.

18. The edge-generated vertical emission laser of claim 16 , further comprising:
a back facet configured to receive a portion of the generated light propagating away from the grating coupler in the waveguide; and
an anti-reflective coating disposed on the back facet.

19. The edge-generated vertical emission laser of claim 16 , further comprising:
a back facet configured to

Assignees

• Apple Inc

Inventors

• Hill Jeffrey T
• Bismuto Alfredo
• Sarmiento Tomas

Classifications

• H01S5/185

  having only horizontal cavities, e.g. horizontal cavity surface-emitting lasers [HCSEL] (comprising a photonic bandgap structure H01S5/11) · CPC title

• H01S5/12

  the resonator having a periodic structure, e.g. in distributed feedback [DFB] lasers (comprising a photonic bandgap structure H01S5/11; surface-emitting lasers H01S5/18) · CPC title

• H01S5/0267

  Integrated focusing lens (H01S5/18388 takes precedence) · CPC title

• H01S5/42

  Arrays of surface emitting lasers · CPC title

• H01S5/028

  Coatings {; Treatment of the laser facets, e.g. etching, passivation layers or reflecting layers} · CPC title