Cryogenic cooling of diode laser with coolant recovery

Patent metadata

Field	Value
Publication number	US-9966731-B2
Application number	US-201514873049-A
Country	US
Kind code	B2
Filing date	Oct 1, 2015
Priority date	Oct 1, 2014
Publication date	May 8, 2018
Grant date	May 8, 2018

Abstract

A laser system includes a plurality of diode lasers, a cryogenic cooling system circulating a cryogenic coolant and coupled to the plurality diode lasers to cool the plurality of diode lasers with the cryogenic coolant, and a fuel cell coupled to the plurality of diode lasers to power the plurality of diode lasers and situated to receive the cryogenic coolant from the cryogenic cooling system as fuel for the fuel cell. A method of operating a high power laser system includes cooling a plurality of diode lasers with a cryogenic cooling system circulating a cryogenic coolant, fueling a fuel cell with a portion of the cryogenic coolant circulating in the cryogenic cooling system, and powering the plurality of diode lasers with power generated by the fuel cell.

First claim

What is claimed is:

1. A laser system comprising:
a plurality of diode lasers;
a cryogenic cooling system circulating a cryogenic coolant and coupled to the plurality diode lasers to cool the plurality of diode lasers with the cryogenic coolant; and
a fuel cell coupled to the plurality of diode lasers to power the plurality of diode lasers and situated to receive the cryogenic coolant from the cryogenic cooling system as fuel for the fuel cell.

2. The laser system of claim 1 , wherein the cryogenic coolant is methane.

3. The laser system of claim 1 , wherein the cryogenic cooling system includes coolant reservoir and a throttle valve, the throttle valve being situated to receive liquid coolant from the reservoir and situated to expand the liquid coolant into a coolant gas so as to cool diode laser junctions of the plurality of diode lasers.

4. The laser system of claim 3 , wherein a portion of the coolant gas is directed into a housing of the diode lasers and is subsequently received by the fuel cell as fuel.

5. The laser system of claim 4 , wherein the coolant gas in the housing prevents condensation therein.

6. The laser system of claim 4 , wherein after cooling the plurality of diode lasers coolant gas which is not directed into the housing is liquefied with a liquefier and returned back to the reservoir.

7. The laser system of claim 4 , further comprising a gas purge system coupled to the cryogenic cooling system, the gas purge system situated to purge coolant gas from the cooling system and from the laser housing in order to maintain low dew points therein.

8. The laser system of claim 1 , wherein the fuel cell generates sufficient energy to power the plurality of diode lasers, laser drive electronics associated with the diode lasers, and laser power supplies associated with the diode lasers.

9. The laser system of claim 6 , wherein the fuel cell generates sufficient energy to power the plurality of diode lasers and the liquefier.

10. The laser system of claim 1 , wherein the plurality of diode lasers are situated to generate at least 1 kW of optical output.

11. The laser system of claim 1 , wherein the plurality of diode lasers is powered entirely by the fuel cell.

12. A method of operating a high power laser system, the method comprising:
cooling a plurality of diode lasers with a cryogenic cooling system circulating a cryogenic coolant;
fueling a fuel cell with a portion of the cryogenic coolant circulating in the cryogenic cooling system; and
powering the plurality of diode lasers with power generated by the fuel cell.

13. The method of claim 12 , wherein the cryogenic coolant is methane.

14. The method of claim 13 , wherein the plurality of diode lasers are cooled by controllably expanding the liquid coolant to coolant gas with a throttle valve.

15. The method of claim 14 , wherein a portion of the coolant gas is directed into a laser housing of the diode lasers in order to provide further cooling and to prevent condensation.

16. The method of claim 15 , wherein the coolant gas directed into the laser housing is further directed to the fuel cell to provide fuel thereto.

17. The method of claim 15 , wherein the coolant gas that is not directed into the laser housing is liquefied with a liquefier and returned to a coolant reservoir.

18. The method of claim 12 , wherein the fuel cell powers the plurality of diode lasers generating an optical output of at least 10 kW.

19. A method of operating a high power laser system, the method comprising:
cooling a plurality of diode lasers with a cryogenic coolant;
fueling a gas turbine with a portion of the cryogenic coolant; and
powering the plurality of diode lasers with power generated by the gas turbine.

20. The method of claim 19 , wherein coolant not used by the gas turbine is liquefied and recirculated to a reservoir to provide further cooling to the plurality of diode lasers.

Assignees

• Nlight Photonics Corp
• Nlight Inc

Inventors

• Kanskar Manoj
• Sanders Walter R

Classifications

• H01S5/0207

  Substrates having a special shape · CPC title

• F25D19/006

  Thermal coupling structure or interface · CPC title

• H01S5/042

  Electrical excitation {; Circuits therefor (monolithically integrated laser drive components H01S5/0261)} · CPC title

• F25B19/005

  the refrigerant being a liquefied gas · CPC title

• F05D2220/32

  in gas turbines · CPC title