Automated laser diode test system

• US 6,873,172 B2
• Filed: 05/14/2002
• Issued: 03/29/2005
• Est. Priority Date: 05/14/2001
• Status: Active Grant

• Current Assignee: NeoPhotonics Corporation (Lumentum Holdings Inc.)
• Original Assignee: Bandwidth9, Inc.
• Inventors: Cornelius, Paul, Walsh, John, Yim, Yong
• Primary Examiner(s): KARLSEN, ERNEST F
• Application Number:
  US10/146,709
• Publication Number:
  US 20020186744A1
• Time in Patent Office: 1,050 Days
• Field of Search: 324/767, 324/158.1, 324/760, 324/765, 324/766, 702/182, 702/183, 702/185
• US Class Current: 324/762.02
• CPC Class Codes: H01S 5/0014 Measuring characteristics or properties thereof measuring techniques per se G01J, G01K, G01N, G01R
• CPC Class Codes: H01S 5/0021 Degradation or life time measurements
• CPC Class Codes: H01S 5/042 Electrical excitation ; Circuits therefor monolithically integrated laser drive components H01S5/0261

Abstract

An automated laser diode testing and burn-in system is disclosed. Initial device data is obtained by applying current to the device at room temperature and measuring the device parameters. The device is then subjected to a burn-in process at higher temperatures. Device performance is monitored throughout the burn-in process. Upon termination of the burn-in process the devices are cooled to room temperature and the post burn-in device power is measured again under the same test conditions. If the device parameters have changed by more than a particular amount the device is rejected. Otherwise, the device is accepted and installed in the next level assembly. The test system disclosed herein achieves significant advantages over prior art in cost and throughput by combining an easy to load laser test fixture with automatic device hold down feature, heating capability, computer program driven test protocol capable of performing initial laser measurements, calibrating each laser and photodetector pair, burn-in test, post burn-in measurements, failed device detection, storage of laser test history records and enabling remote access to such records. The invention eliminates the need for numerous labor intensive ergonomically difficult steps and costly test fixtures.

Claims

1. A method for testing lasers, comprising:

providing a browser user interface module to a server,

providing a module enabling communications between the server, a parametric tester and an embedded controller; and

storing and retrieving test parameters and test data collected and enabling information retrieval by a plurality of local and remote users.

2. The method of claim 1, further comprising:

maintaining traceability of test data for each of a laser tested and to a specific location within a heater assembly.

3. The method of claim 2, further comprising:

detecting a location of a plurality of heater assemblies.

4. The method of claim 3, further comprising:

identifying each heater assembly.

5. The method of claim 1, further comprising:

recording a laser serial number for each of a tested laser.

6. The method of claim 1, further comprising:

performing a laser parametric test for each of a laser.

7. The method of claim 6, further comprising:

performing a calibration of each laser and a detector combination.

8. The method of claim 7, further comprising:

monitoring and adjusting a temperature of each of a laser tested to a predetermined value.

9. The method of claim 8, further comprising:

terminating a burn-in testing of each of a laser tested that does not conform to a predetermined value.

10. The method of claim 9, further comprising:

comparing a pre burn-in to a post burn-in a laser parametric test result; and

rejecting each of a tested laser when the laser parametric test result exceeds a predetermined value.

11. The method of claim 10, further comprising:

providing an embedded controller member for identifying each heater assembly; and

retrieving predetermined burn-in test conditions from the server.

12. The method of claim 11, further comprising:

continually monitoring temperature of lasers being tested.

13. The method of claim 12, further comprising:

providing a constant current or a constant power burn-in condition to lasers being tested.

14. The method of claim 13, further comprising:

measuring and adjusting test parameters to obtain constant power conditions for tested lasers.

15. The method of claim 14, further comprising:

storing laser test data and communicating the data to the server.

16. The method of claim 15, further comprising:

restarting a burn-in test if an interruption occurs during burn-in.

17. The method of claim 16, further comprising:

terminating the burn-in test and communicating the test termination message to the server.