Title:
POLARIZATION DIVERSITY LIGHT RECEIVING CIRCUIT
Document Type and Number:
Japanese Patent JP2016099568
Kind Code:
A
Abstract:
PROBLEM TO BE SOLVED: To solve the conventional problems in which, when an optical fiber is used to perform signal comparison in an optical frequency domain (optical carrier) in order to perform frequency comparison between faraway optical clocks, variation is caused by a disturbance such as vibration on a polarization surface of return light, and hence the polarization must be adjusted with a polarizer or the like, and, when the performance of a system for compensating the frequency variation due to the temperature of the optical fiber is evaluated, the polarization state of the signal light and local emission light varies with time, and hence control is required using the polarizer so that they are in mutually parallel state.SOLUTION: Two lights branched by PBS are received by respective optical receivers and are converted into electric signals, and then each electric signal is passed through a circuit for squaring each electric signal and a circuit for adding the squared electric signals. The added signal is converted into an electric signal that is not affected by the polarization of the signal light, by passing a signal component of an electric region proportional to the difference between the optical frequencies of the signal light and local emission light through a band pass filter.SELECTED DRAWING: Figure 4
Inventors:
AMAMIYA MASAKI
Application Number:
JP2014238010A
Publication Date:
May 30, 2016
Filing Date:
November 25, 2014
Export Citation:
Assignee:
NAT INST ADVANCED IND SCIENCE & TECH
International Classes:
G02F2/00
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