OPTICAL RECEIVER AND LIGHT RECEIVING METHOD

• US 20140334831A1
• Filed: 07/28/2014
• Published: 11/13/2014
• Est. Priority Date: 02/23/2012
• Status: Active Grant

• Current Assignee: Fujitsu Optical Components Limited (Fujitsu Limited)
• Original Assignee: Fujitsu Optical Components Limited (Fujitsu Limited)
• Inventors: ISHII, Yuji, AKASHI, Tamotsu, KAWAZOE, Kenichi, TERADA, Koji
• Granted Patent: US 9,344,199 B2
• Time in Patent Office: Days
• US Class Current: 398/210
• CPC Class Codes: A61M 2209/082 Mounting brackets, arm supports for equipment
• CPC Class Codes: A61M 2209/084 Supporting bases, stands for equipment
• CPC Class Codes: A61M 5/1456 with a replaceable reservoir comprising a piston rod to be moved into the reservoir, e.g. the piston rod is part of the removable reservoir
• CPC Class Codes: A61M 5/1458 Means for capture of the plunger flange
• CPC Class Codes: H04B 10/616 Details of the electronic signal processing in coherent optical receivers
• CPC Class Codes: H04B 10/693 Arrangements for optimizing the preamplifier in the receiver

Abstract

An optical receiver receives coherent light. The optical receiver includes an amplitude adjuster, a signal processor, and a controller. The amplitude adjuster adjusts amplitude of an input signal to output an analog signal. The signal processor receives a digital signal generated from the analog signal output from the amplitude adjuster, extracts clock components from the digital signal, and after establishing synchronization between the clock components and data components, extracts the data components from the digital signal to process the data components. The controller sets amplitude of the analog signal to first amplitude before establishment of synchronization by the digital signal, and changes the set amplitude to second amplitude that is smaller than the first amplitude after the establishment of synchronization.

Claims

1. An optical receiver that receives coherent light, the optical receiver comprising:

an amplitude adjuster that adjusts amplitude of an input signal to output an analog signal;

a signal processor that receives a digital signal generated from the analog signal output from the amplitude adjuster, extracts clock components from the digital signal, and after establishing synchronization between the clock components and data components, extracts the data components from the digital signal to process the data components; and

a controller that sets amplitude of the analog signal to first amplitude before establishment of synchronization by the digital signal, and changes the set amplitude to second amplitude that is smaller than the first amplitude after the establishment of synchronization.

2. The optical receiver according to claim 1, wherein the first amplitude includes a value equal to or larger than an amplitude value with which the signal processor is able to establish synchronization between the clock components and the data components by using the digital signal.

3. The optical receiver according to claim 1, wherein the second amplitude includes a value within a range of amplitude values with which the signal processor is able to extract the data components from the digital signal.

4. The optical receiver according to claim 1, wherein the controller limits the second amplitude to amplitude within a range having linearity with respect to a gain characteristic of output amplitude over control voltage applied to the amplitude adjuster after the establishment of synchronization.

5. A light receiving method comprising:

adjusting amplitude of an input signal to output an analog signal;

receiving a digital signal generated from the output analog signal;

extracting clock components from the digital signal;

extracting, after establishing synchronization between the clock components and data components, the data components from the digital signal to process the data components;

setting amplitude of the analog signal to first amplitude before establishment of synchronization by the digital signal; and

changing the set amplitude to second amplitude that is smaller than the first amplitude after the establishment of synchronization.