Laser diode module with integral cooling

• US 6,072,814 A
• Filed: 05/30/1997
• Issued: 06/06/2000
• Est. Priority Date: 05/30/1997
• Status: Expired due to Fees

• Current Assignee: Marconi Data Systems Incorporated (Danaher Corporation)
• Original Assignee: Videojet Systems International Incorporated (Danaher Corporation)
• Inventors: Peterson, Brian L., Jackson, John E., Sarro, Carl J., Ryan, Daniel J.
• Primary Examiner(s): Lee, John D.
• Application Number:
  US08/866,472
• Time in Patent Office: 1,103 Days
• Field of Search: 372/34-36, 372/43, 372/70, 372/75, 372/92, 372/98, 372/101, 372/109, 385/31, 385/33, 385/88, 385/92, 385/93
• US Class Current: 372/35
• CPC Class Codes: G02B 6/4204 the coupling comprising intermediate optical elements, e.g. lenses, holograms encapsulated active devices H01S5/02208, H01L33/52
• CPC Class Codes: G02B 6/422 Active alignment, i.e. moving the elements in response to the detected degree of coupling or position of the elements G02B6/4233, G02B6/4234 take precedence
• CPC Class Codes: G02B 6/4221 involving a visual detection of the position of the elements, e.g. by using a microscope or a camera
• CPC Class Codes: G02B 6/4239 Adhesive bonding; Encapsulation with polymer material
• CPC Class Codes: G02B 6/424 Mounting of the optical light guide
• CPC Class Codes: G02B 6/4245 Mounting of the opto-electronic elements
• CPC Class Codes: G02B 6/4251 Sealed packages G02B6/4248 takes precedence
• CPC Class Codes: G02B 6/4268 Cooling of semiconductor devices H01L23/24; of electric apparatus H05K7/20; of instruments G12B15/00
• CPC Class Codes: G02B 6/4286 Optical modules with optical power monitoring
• CPC Class Codes: H01S 5/02251 using optical fibres
• CPC Class Codes: H01S 5/02423 Liquid cooling, e.g. a liquid cools a mount of the laser
• CPC Class Codes: H01S 5/4025 Array arrangements, e.g. constituted by discrete laser diodes or laser bar H01S5/42 takes precedence

Abstract

A laser module with integral cooling is disclosed. The module is intended for coupling to a fiber optic cable for various applications. The module is generally cylindrical and has a laser diode array mounted centrally therein. A cooling channel is in thermal relation with the array either directly or via a diamond substrate. A fiber optic coupler mates with the portion of the housing carrying the array and carries a lens subassembly. During assembly, the coupler is positioned to accurately focus the output of the array into a beam suitable for transmission to the fiber optic cable. Coolant is coupled to the channel with a removable coupling manifold or similar arrangement which may also carry electrical contacts for energizing the array.

Claims

1. A laser module with integral cooling comprising:

a) a first body section carrying a laser diode array and including means for circulating a liquid coolant in thermal relation with said diode array, said means for circulating includes a channel through which said coolant is circulated and means for connecting a coolant supply to said channel;

b) a second body section optically aligned with and joined to said first body section carrying a lens subassembly for receiving laser energy from said array and projecting it as a beam along an optical path;

c) said second body section including a coupler for removably coupling an optical fiber to said optical path for transmission of said beam externally of the module, said coupler correctly aligning the optical fiber with said optical path.

2. The module of claim 1 wherein said diode array is mounted directly to said channel.

3. The module of claim 1 wherein said diode array is mounted on a substrate which is in thermal relation with said channel.

4. The module of claim 3 wherein said substrate is formed of diamond.

5. The module of claim 1 wherein said means for connecting includes a coolant coupler permitting coolant to enter and exit said first body section and further including a manifold for releasably engaging said coolant coupler, said manifold being in communication with said coolant supply.

6. The module of claim 1 wherein said means for circulating includes a channel in thermal relation with said diode array through which said coolant is circulated and wherein said means for connecting includes plugs for releasably engaging a tube disposed in said channel through which coolant flows, said plugs communicating with said coolant supply, said tube being in thermal relation with said diode array.

7. The module of claim 1 wherein said first body section includes means for permitting alignment of said laser diode array with said lens subassembly during assembly of said module by monitoring the output of said lens subassembly.

8. The module of claim 1 wherein said second body section is bonded to said first body section.

9. The module of claim 1 wherein the lens subassembly is disposed in an optical coupler secured to said second body section.

10. The module of claim 9 wherein said optical coupler is secured to said second body section at a position selected to accurately focus the laser beam along said optical path.

11. The module of claim 9 wherein said optical coupler includes means for coupling an external optical cable to said optical path.

12. The module of claim 1 wherein a ceramic disk is disposed between and secured to said first and second body sections, said laser diode array being mounted to said disk.

13. The module of claim 12 wherein said laser diode array is mounted to said disk via a diamond substrate.

14. A method of constructing a laser module and connecting an optical fiber thereto comprising the steps of:

a) providing a first body section having a laser diode array rigidly attached thereto and a liquid coolant channel in thermal relation with said diode array through which coolant may be circulated;

b) providing a second body section having a lens subassembly rigidly attached thereto and means for removably coupling an optical fiber to said second body section;

c) activating said laser diode array to project laser energy from said array through said lens subassembly;

d) monitoring the output of said lens subassembly;

e) optically aligning said first and second body sections based on the output of said lens subassembly;

f) rigidly securing said first and second body sections in said optically aligned state to create a fixed optical path; and

g) connecting an optical fiber to the optical path via said coupling means, whereby the optical fiber is correctly aligned with said optical path.

15. A method according to claim 14 wherein said step of rigidly securing said first and second body sections comprises rigidly fixing said first and second body sections to one another.

16. A method according to claim 15 wherein said step of rigidly fixing said first and second body sections to one another comprises bonding said first and second body sections to one another.

17. A method according to claim 14 wherein the step of optically aligning said first and second body sections is performed by setting focus and power output using a predetermined duty cycle of operation of said laser diode array.