Cooler for optics transmitting high intensity light

Patent metadata

Field	Value
Publication number	US-10747033-B2
Application number	US-201615010188-A
Country	US
Kind code	B2
Filing date	Jan 29, 2016
Priority date	Jan 29, 2016
Publication date	Aug 18, 2020
Grant date	Aug 18, 2020

Abstract

A system and an apparatus having an optic and a cooling system for cooling the optic. In one example an optically addressed light valve forms the optic. The cooling system includes first and second windows on opposing surfaces of the optically addressed light valve which constrain a cooling fluid to flow over the opposing surfaces. The fluid pressure outside the optically addressed light valve is low enough that it does not compress a liquid crystal gap of the optically addressed light valve. The cooling fluid is also transparent to a high powered light beam which is projected through the first and second windows, and also through the optically addressed light valve, during an additive manufacturing operation.

First claim

The claims are:

1. An apparatus configured to transmit power fluxes sufficiently high for use in additive manufacturing a part, the apparatus comprising:
an optic configured to be thermally managed,
a light source configured to produce a light beam adapted to be directed through the optic,
an optic cooling system in flow communication with said optic, the optic cooling system including first and second windows for sandwiching the optic between the first and second windows while allowing the light beam to pass through the windows, and
wherein the first and second windows operate to contain a flowing cooling fluid in contact with, and flowing over, opposing surfaces of the optic, to help cool the optic, and where the cooling fluid is transparent to the light beam when the light beam is transmitted through the cooling fluid.

2. The apparatus of claim 1 , wherein said light source comprises a laser, and said light beam comprises a laser beam having energy which is transferred to said optic as heat, and wherein said optic cooling system removes said heat from said optic.

3. The apparatus of claim 1 , wherein said light source comprises a diode laser, and said light beam comprises a laser beam having heat, and wherein said heat is transferred to said optic, and wherein said optic cooling system removes said heat from said optic.

4. The apparatus of claim 1 , wherein said optic comprises an optically addressed light valve including:
a semiconductor material transparent to the light beam which is optically stimulated to induce a change in semiconductor conductivity,
a layer of liquid crystal for rotating a polarization state of the light beam as the light beam transmits through the optically addressed light valve,
a substrate material transparent to the light beam,
optically transparent electrically conductive coatings on an outside of the semiconductor material, and between the layer of liquid crystal and the substrate material, and
anti-reflective coatings on two opposing sides of the semiconductor material, and on two opposing sides of the substrate material.

5. The apparatus of claim 4 wherein said semiconductor material is transparent to 1053 nm light.

6. The apparatus of claim 4 wherein said substrate material is transparent to 1053 nm light.

7. The apparatus of claim 4 , wherein said liquid crystal is made of twisted nematic E7.

8. The apparatus of claim 4 , wherein said transparent electrically conductive coatings are made of Indium Tin Oxide.

9. The apparatus of claim 1 wherein said light beam is comprised of light in one polarization state.

10. The apparatus of claim 1 , wherein said optic comprises an optically addressed light valve including:
a semiconductor material:
a liquid crystal portion for selectively rotating a polarization state of the light beam as the light beam transmits through the optically addressed light valve;
a secondary light source for projecting patterned light of a wavelength tuned to an absorption band of the semiconductor material, and
a polarizing mirror capable of separating orthogonal polarization states induced by polarization rotation of the light beam in the liquid crystal portion.

11. The apparatus of claim 1 , wherein said optic cooling system includes a housing for housing said optic and receiving the cooling fluid in said housing.

12. The apparatus of claim 1 , wherein:
said optic cooling system includes a housing which places said cooling fluid in communication with said optic,
wherein said cooling fluid is circulated in said housing, and
wherein said apparatus further includes a heat exchanger in flow communication with said cooling fluid.

13. The apparatus of claim 1 , wherein said optic cooling system includes:
a housing which houses said optic,
said cooling fluid,
a circulation system for configured to circulate said cooling fluid in said housing,
a pump operatively connected to said circulation system, and
a heat exchanger operatively connected to said circulation system.

14. An apparatus configured to transmit power fluxes sufficiently high for carrying out an additive manufacturing operation to form a part from a powdered material, the apparatus comprising:
an optic having opposing side surfaces;
a light source configured to generate a light beam adapted to be directed through the optic; and
an optic cooling system in flow communication with said optic, the optic cooling system including:
first and second windows arranged adjacent to the opposing side surfaces of the optic, which sandwich the optic therebetween, and which contain a cooling fluid flowing through the optic cooling system in contact with the opposing side surfaces, and flowing over the opposing side surfaces of the optic while, still allowing passage of the light beam through the first and second windows and cross-sectionally through the optic, and
where the cooling fluid is substantially transparent to the light beam when the light beam is transmitted through the cooling fluid.

15. The apparatus of claim 14 , wherein the optic cooling system includes a housing having at least one inlet and at least one outlet.

16. The apparatus of claim 15 , wherein the housing includes:
a first housing body part;
a second housing body part, the first and second housing body parts cooperatively enclosing the optic;
at least one inlet for receiving the cooling fluid;
a pair of coolant fluid flow paths running along the opposing surfaces of the optic for circulating the cooling fluid over the opposing surfaces of the optic; and
at least one outlet for receiving the cooling fluid after the cooling fluid passes over the opposing surfaces of the optic.

17. The apparatus of claim 16 , wherein the at least one inlet comprises a pair of inlets, and wherein the at least one outlet comprises a pair of outlets.

18. The apparatus of claim 16 , further comprising a heat exchanger in communication with the at least one outlet, which receives the cooling fluid and helps to cool the cooling fluid.

19. An apparatus configured to transmit power fluxes sufficiently high for carrying out an additive manufacturing operation on a material, the apparatus comprising:
an optic having opposing side surfaces;
a light source configured to generate a light beam adapted to be directed through the optic;
an optic cooling system in flow communication with said optic and enclosing said optic, the optic cooling system including:
a cooling fluid;
a housing having a pair of windows arranged adjacent to the opposing side surfaces of the optic which form a pair of coolant flow paths along the opposing side surfaces, the windows configured to constrain the cooling fluid in contact with the opposing side surfaces of the optic, while enabling transmission of the light beam through the pair of windows, and thus cross-sectionally through the optic; and

wherein the cooling fluid circulating over the opposing side surfaces of the optic help to prevent deformation of the optic, and where the cooling fluid is at least transparent to the light beam that is transmitted through the pair of windows, through the optic and through the cooling fluid.

20. The apparatus of claim 19 , further comprising a heat exchanger in communication with the optic cooling system for receiving and cooling the cooling fluid after the cooling fluid has passed through the optic cooling system.

21. The apparatus of claim 20 , further comprising:
a coolant supply reservoir in communication with the optic cooling system f

Assignees

• L Livermore Nat Security Llc

Inventors

• Demuth James A
• Duoss Eric B
• Kuntz Joshua D
• Rosso Paul A
• Spadaccini Christopher M

Classifications

• B22F10/10

  Formation of a green body · CPC title

• B22F12/20

  Cooling means · CPC title

• B22F10/28

  Powder bed fusion, e.g. selective laser melting [SLM] or electron beam melting [EBM] · CPC title

• B22F12/41

  characterised by the type, e.g. laser or electron beam · CPC title

• B29C64/268 Primary

  using laser beams; using electron beams [EB] · CPC title