Methods and systems for control and calibration of VCSEL-based optical transceivers

• US 6,512,617 B1
• Filed: 02/03/1999
• Issued: 01/28/2003
• Est. Priority Date: 02/03/1998
• Status: Expired due to Term

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Applied Micro Circuits Corporation (MACOM Technology Solutions Holdings, Inc.)
• Inventors: Tanji, Todd M., Stronczer, John J.
• Primary Examiner(s): Chan, Jason
• Assistant Examiner(s): Payne, David C
• Application Number:
  US09/243,583
• Time in Patent Office: 1,455 Days
• Field of Search: 359/152, 359/121, 455/343
• US Class Current: 398/137
• CPC Class Codes: H04B 10/40 Transceivers

Abstract

An optical transceiver system includes circuitry including a light-emitting device, a driver for the light-emitting device being coupled to the light-emitting device for providing activating power to said light-emitting device and an optical detector disposed to receive light emitted from the light-emitting device, said circuitry being substantially constructed using CMOS technology. A calibration interface is coupled to the circuitry for automatically executing an iterative cycle for a calibration of optical link parameters. And, an optical loop-back is included for optically coupling the light-emitting device and the optical detector, the optical detector receiving light emitted by the light-emitting device, the light emission being selectively stimulated by the calibration interface, the received light emission being communicated to the calibration interface for comparison with a known light signal. A method of automatic calibration and control of optical link parameters in a VCSEL-based optical transceiver is included.

Claims

1. A method of automatic calibration and control of optical link parameters in a VCSEL-based optical transceiver, the method comprising:

inserting an optical loop-back to optically couple an optical transmitter and an optical receiver;

initiating a calibration cycle by an input signal;

setting a first parameter to zero;

reading a target ‘

0’

value from a memory location;

generating a first light emission based upon the first parameter;

feeding the first light emission back to the optical detector through the optical loop-back;

comparing a value representing the first light emission to the target ‘

0’

value;

setting a second parameter to zero;

reading a target ‘

1’

value from a memory location;

generating a second light emission based upon the second parameter value;

feeding the second light emission back to the optical detector through the optical loop-back; and

comparing a value representing the second light emission to the target ‘

1’

value.

2. The method of claim 1, further comprising:

determining whether the second light emission value is greater than or equal to the target ‘

1’

value; and

incrementing a modulation current if the second light emission value is not greater than or equal to the target ‘

1’

value.

3. The method of claim 2, further comprising:

storing the second parameter, if the light emission value is greater than or equal to the target ‘

1’

value, in a memory location.

4. The method of claim 1, further comprising:

determining whether the first light emission value is greater than or equal to the target ‘

0’

value; and

incrementing a bias current if the first light emission value is not greater than or equal to the target ‘

0’

value.

5. The method of claim 4, further comprising:

storing the first parameter, if the light emission value is greater than or equal to the target ‘

0’

value, in a memory location.