Reflection/absorption coating for metallurgical bonding to a laser gain medium

Patent metadata

Field	Value
Publication number	US-9972960-B1
Application number	US-201615381521-A
Country	US
Kind code	B1
Filing date	Dec 16, 2016
Priority date	Dec 16, 2016
Publication date	May 15, 2018
Grant date	May 15, 2018

Abstract

An active optical planar waveguide apparatus includes a planar core layer comprising an active laser ion; one or more cladding layers in optical contact with at least one surface of the planar core layer; a metallic binder layer chemically bonded to an outermost cladding layer of the one or more cladding layers; a metallic adhesion layers disposed on the metallic binder layer; a heatsink for dissipating heat from the planar waveguide; and a metallic thermal interface material (TIM) layer providing a metallurgical bond between the metallic adhesion layer and the heatsink.

First claim

What is claimed is:

1. An active optical planar waveguide apparatus, comprising:
a planar core layer comprising an active laser ion, the planar core layer guiding light in only one dimension;
one or more cladding layers in optical contact with at least one surface of the planar core layer;
a metallization layer comprising one or more metallic layers chemically bonded to an outermost cladding layer of the one or more cladding layers;
a heatsink for dissipating heat from the planar waveguide; and
a metallic thermal interface material (TIM) layer providing a metallurgical bond between the metallization layer and the heatsink, the TIM having a thickness of about 10 to about 200 micrometers.

2. The active optical planar waveguide apparatus of claim 1 , wherein the metallization layer comprises two layers, a metallic binder layer and a metallic adhesion layer, and the metallic TIM is arranged between the metallic adhesion layer and the heatsink.

3. The active optical planar waveguide apparatus of claim 2 , wherein the metallic binder layer has a thickness equal to or less than 1/10 wave at a laser wavelength.

4. The active optical planar waveguide apparatus of claim 2 , wherein the metallic binder layer is chromium, titanium, tungsten, nickel, or any combination thereof.

5. The active optical planar waveguide apparatus of claim 2 , wherein the metallic adhesion layer is silver, copper, gold, nickel, or any combination thereof.

6. The active optical planar waveguide apparatus of claim 2 , wherein a reflectivity at the one or more cladding layers to metallic binder layer interface is less than 50% from 0 to 30 degrees angles of incidence.

7. The active optical planar waveguide apparatus of claim 1 , wherein a reflectivity at the one or more cladding layers to metallic binder layer interface is less than 20% from 0 to 45 degrees angles of incidence.

8. The active optical planar waveguide apparatus of claim 2 , further comprising one or more additional metallic or dielectric layers disposed between the metallic binder layer and the metallic adhesion layer.

9. The active optical planar waveguide apparatus of claim 8 , wherein the one or more additional dielectric layers is germanium, silicon, SiO 2 , HfO 2 , Nb 2 O 5 , Ta 2 O 5 , or any combination thereof.

10. The active optical planar waveguide apparatus of claim 1 , wherein the metallic TIM is silver, gold, indium, copper, or a metal solder, and the TIM has a thickness in a range from about 10 to about 200 microns.

11. The active optical planar waveguide apparatus of claim 1 , wherein the heatsink has a coefficient of thermal expansion (CTE) matched to the planar core layer to within 2 parts per million/degrees Celsius (ppm/° C.).

12. A method of making an active planar waveguide apparatus, the method comprising:
depositing a metallic binder layer on a surface of an optically flat surface of a planar waveguide, the planar waveguide guiding light in only one dimension;
depositing a metallic adhesion layer on the metallic binder layer; and
bonding by a metallurgical process a heatsink to the waveguide using a metallic thermal interface material (TIM) between the metallic adhesion layer and the heatsink, the metallic TIM having a thickness of about 10 to about 200 micrometers.

13. The method of claim 12 , wherein the metallic TIM is silver, copper, indium, or a combination thereof.

14. The method of claim 12 , wherein the metallic TIM comprises a sintered metal.

15. The method of claim 12 , wherein the sintered metal is formed from nanoparticles.

16. The method of claim 15 , wherein an intermediate layer of metal or dielectric material is deposited between the metallic binder layer and the metallic adhesion layer.

17. A passive optical planar waveguide apparatus, comprising:
one or more optically transparent planar waveguide substrates in optical contact with one another, the one or more optically transparent planar waveguide substrates guiding light in only one dimension;
a metallic binder layer chemically bonded to an outermost optical layer of the one or more optically transparent substrates;
one or more metallic adhesion layers disposed on the metallic binder layer; and
a metallic thermal interface material (TIM) layer forming a metallurgical bond to the metallic adhesion layer, the metallic TIM having a thickness of about 10 to about 200 micrometers.

18. The passive optical planar waveguide apparatus of claim 17 , further comprising an additional metal layer disposed between the metallic binder layer and the one or more metallic adhesion layers.

19. The passive optical planar waveguide apparatus of claim 17 , further comprising an additional dielectric layer disposed between the metallic binder layer and the one or more metallic adhesion layers.

20. The passive optical planar waveguide apparatus of claim 19 , wherein the additional dielectric layer is germanium, silicon, SiO 2 , HfO 2 , Nb 2 O 5 , Ta 2 O 5 , or any combination thereof.

21. The passive optical planar waveguide apparatus of claim 17 , wherein the metallic binder layer is chromium, titanium, tungsten, nickel, or any combination thereof.

22. The passive optical planar waveguide apparatus of claim 17 , wherein the one or more metallic adhesion layers is silver, copper, gold, nickel, or any combination thereof.

23. The passive optical planar waveguide apparatus of claim 17 , wherein the metallic TIM is silver, gold, indium, copper, or a metal solder, and the TIM has a thickness in a range from about 10 to about 200 microns.

24. The passive optical planar waveguide apparatus of claim 17 , wherein a reflectivity at the one or more optically transparent substrates to metallic binder layer interface is less than 50% from 0 to 30 degrees angles of incidence.

Assignees

• Raytheon Co

Inventors

• Koontz Christopher R
• Filgas David M
• Ketola Kurt S
• Townsend Carl W

Classifications

• H01S3/0405

  Conductive cooling, e.g. by heat sinks or thermo-electric elements · CPC title

• H01S3/1618

  ytterbium · CPC title

• H01S3/1611

  neodymium · CPC title

• H01S3/094003

  the pumped medium being a fibre · CPC title

• H01S3/1608

  erbium · CPC title