Optical receiver for regeneration of optical signal

• US 20070081827A1
• Filed: 01/30/2006
• Published: 04/12/2007
• Est. Priority Date: 10/11/2005
• Status: Abandoned Application

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Yamabana, Tetsuji, Ide, Satoshi
• Application Number:
  US11/341,535
• Publication Number:
  US 20070081827A1
• Time in Patent Office: Days
• US Class Current: 398/209
• CPC Class Codes: H04B 10/66 Non-coherent receivers, e.g. using direct detection

Abstract

An optical receiver includes: a converting unit that converts an optical signal into an electrical signal; an amplifying unit that amplifies the electrical signal; a regenerating unit that regenerates the amplified electrical signal; a correcting unit that performs correction of an error included in the regenerated electrical signal; a monitoring unit that performs monitoring of an optical current flowing through the converting unit; and a control unit that calculates a decision threshold based on a result of the correction and a result of the monitoring.

Claims

1. An optical receiver comprising:

a converting unit that converts an optical signal into an electrical signal;

an amplifying unit that amplifies the electrical signal;

a regenerating unit that regenerates the electrical signal amplified by the amplifying unit;

a correcting unit that performs correction of an error included in the electrical signal regenerated by the regenerating unit;

a monitoring unit that performs monitoring of an optical current flowing through the converting unit; and

a control unit that calculates a decision threshold based on a result of the correction and a result of the monitoring.

2. The optical receiver according to claim 1, further comprising a feedback unit that controls a direct current level of a signal output from the amplifying unit by branching a part of the signal to be fed back to the amplifying unit.

3. The optical receiver according to claim 2, wherein the decision threshold is input to the feedback unit.

4. The optical receiver according to claim 1, further comprising:

a pre-stage amplifying unit that outputs a signal to the amplifying unit;

a supplying unit that supplies a current to the pre-stage amplifying unit; and

a feedback unit that controls a direct current level of a signal output from the amplifying unit by branching a part of the signal output from the pre-stage amplifying unit to be input to the supplying unit.

5. The optical receiver according to claim 4, wherein the decision threshold is input to the feedback unit.

6. The optical receiver according to claim 1, wherein the decision threshold is input to the regenerating unit.

7. The optical receiver according to claim 1, wherein the control unit includes an analog operating unit.

8. The optical receiver according to claim 1, wherein the control unit includes

a controller that outputs a normalized threshold corresponding to the result of the correction;

and

a calculator that calculates the decision threshold based on the result of the monitoring and the normalized threshold.

9. The optical receiver according to claim 1, wherein the amplifying unit includes a limiting amplifier.