IP Library Granted Patent US 10,230,212
Granted Patent B1
US 10,230,212 · App. 15/852,475 · Granted Mar 12, 2019

Method and apparatus to prevent laser kink failures

Inventors: Mudasir Ahmad (San Jose, CA); Weidong Xie (San Ramon, CA); Yaoyu Pang (Katy, TX); Chiyu Liu (San Diego, CA); Qiang Wang (Zhejiang, CN)
Assignee: Cisco Technology, Inc.
H01S5/02256H05K1/181H05K2201/068H05K2201/09563H05K2201/10121
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Quick Facts
Patent No.
US 10,230,212
App. No.
15/852,475
Granted
Mar 12, 2019
Kind
B1
Abstract

Systems, devices, methods, and computer-readable media for preventing laser kink failures. A laser diode device can include one or more laser diodes configured to emit electromagnetic radiation coherently. The laser diode device can also include one or more submounts upon which the one or more laser diodes are mounted. The one or more submounts can include one or more through vias including one or more fill materials different from a material of the one or more submounts. Further, one or more properties of the one or more through vias in the one or more submounts can be selected to reduce an amount of mismatch between an effective coefficient of thermal expansion of the one or more laser diodes and an effective coefficient of thermal expansion of the one or more submounts.

Claims (25)

1. A laser diode device comprising:

one or more laser diodes configured to emit electromagnetic radiation coherently; and

one or more submounts upon which the one or more laser diodes are mounted, the one or more submounts including one or more through vias including one or more fill materials different from a material of the one or more submounts, one or more properties of the one or more through vias in the one or more submounts selected to reduce an amount of mismatch between an effective coefficient of thermal expansion of the one or more laser diodes and an effective coefficient of thermal expansion of the one or more submounts.

2. The laser diode device of claim 1 , wherein reducing the amount of mismatch between the effective coefficient of thermal expansion of the one or more laser diodes and the effective coefficient of thermal expansion of the one or more submounts reduces an amount of bow in the one or more laser diodes caused by a process of cooling down the one or more laser diodes and the one or more submounts after bonding the one or more laser diodes onto the one or more submounts.

3. The laser diode device of claim 2 , wherein reducing the amount of bow in the one or more laser diodes reduces a chance of kink failure in the one or more laser diodes corresponding to distortions in gratings of the one or more laser diodes caused by the amount of bow in the one or more laser diodes.

4. The laser diode device of claim 1 , wherein the one or more properties of the one or more through vias include at least one of a number of the one or more through vias, dimensions of the one or more through vias, a density of the one or more through vias in a volume of the one or more submounts, and the one or more fill materials of the one or more through vias.

5. The laser diode device of claim 1 , wherein the one or more fill materials of the one or more through vias have a coefficient of thermal expansion greater than a coefficient of thermal expansion of the material of the one or more submounts to increase the effective coefficient of thermal expansion of the one or more submounts.

6. The laser diode device of claim 1 , wherein the one or more fill materials include Copper.

7. The laser diode device of claim 1 , wherein the one or more submounts are fabricated from Silicon.

8. The laser diode device of claim 1 , wherein the one or more properties of the one or more through vias include positions of the one or more through vias in the one or more submounts with respect to positions of the one or more laser diodes mounted to the one or more submounts.

9. The laser diode device of claim 1 , wherein the one or more through vias are disposed in the one or more submounts throughout an entire volume of the one or more submounts.

10. The laser diode device of claim 1 , wherein the one or more through vias are selectively disposed in the one or more submounts in one or more stage areas corresponding to positions of the one or more laser diodes mounted to the one or more submounts.

11. The laser diode device of claim 1 , wherein the one or more properties of the one or more through vias are selected based on dimensions of the one or more laser diodes.

12. The laser diode device of claim 1 , wherein the one or more properties of the one or more through vias are selected based on one or more materials used to attach the one or more laser diodes to the one or more submounts as part of mounting the one or more laser diodes to the one or more submounts.

13. The laser diode device of claim 1 , wherein the one or more properties of the one or more through vias are selected through a finite element analysis model of an amount of bow in a laser diode as a function of an amount of mismatch between effective coefficients of thermal expansion of the laser diode and a submount, the model created based on amounts of bow observed in a laser diode submount assembly lacking through vias in the submount of the laser diode submount assembly and laser diode submount assemblies with submounts including through vias with fill materials having varying through via properties.

14. A method comprising:

identifying one or more submounts and one or more laser diodes to mount to the one or more submounts;

selecting one or more properties of one or more through vias including one or more fill materials different from a material of the one or more submounts, the one or more properties of the one or more through vias including the one or more fill materials selected to reduce an amount of mismatch between an effective coefficient of thermal expansion of the one or more laser diodes and an effective coefficient of thermal expansion of the one or more submounts;

fabricating the one or more submounts according to the one or more properties of the one or more through vias including the one or more fill materials selected to reduce the amount of mismatch between the effective coefficient of thermal expansion of the one or more laser diodes and the effective coefficient of thermal expansion of the one or more submounts; and

mounting the one or more laser diodes to the one or more submounts.

15. The method of claim 14 , wherein reducing the amount of mismatch between the effective coefficient of thermal expansion of the one or more laser diodes and the effective coefficient of thermal expansion of the one or more submounts reduces an amount of bow in the one or more laser diodes caused by a process of cooling down the one or more laser diodes and the one or more submounts after bonding the one or more laser diodes onto the one or more submounts.

16. The method of claim 15 , wherein reducing the amount of bow in the one or more laser diodes reduces a chance of kink failure in the one or more laser diodes corresponding to distortions in gratings of the one or more laser diodes caused by the amount of bow in the one or more laser diodes.

17. The method of claim 14 , wherein the one or more properties of the one or more through vias include at least one of a number of the one or more through vias, dimensions of the one or more through vias, a density of the one or more through vias in a volume of the one or more submounts, and the one or more fill materials of the one or more through vias.

18. The method of claim 14 , wherein the one or more fill materials of the one or more through vias have a coefficient of thermal expansion greater than a coefficient of thermal expansion of the material of the one or more submounts to increase the effective coefficient of thermal expansion of the one or more submounts.

19. The method of claim 14 , wherein the one or more properties of the one or more through vias include positions of the one or more through vias in the one or more submounts with respect to positions of the one or more laser diodes mounted to the one or more submounts.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Dec 22, 2017
From: AHMAD, MUDASIR; XIE, WEIDONG; PANG, YAOYU; LIU, CHIYU; WANG, QIANG
To: CISCO TECHNOLOGY, INC.
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