OPTICAL RECEIVER AND OPTICAL RECEPTION METHOD

摘要

In order to reduce a delay at the time of detecting inputted optical signals in an optical receiver using a variable optical attenuator, the optical receiver includes: a variable optical attenuator that outputs optical signals by attenuating the intensity of inputted optical signals; a photoelectric converter that converts the optical signals into electric signals; an amplitude detection circuit that outputs an output voltage based on the amplitude of the electric signals; an optical attenuator control circuit that outputs signals for controlling an attenuation quantity of the variable optical attenuator based on the output voltage; a signal detection circuit that outputs signal detection output by comparing the output voltage and a signal detection threshold voltage, i.e., reference of signal detection, to each other; and a threshold control circuit, which monitors the output voltage, and which changes the signal detection threshold voltage when an output voltage change state becomes stable with time.

主权项

1. An optical receiver comprising:
a variable optical attenuator that attenuates an intensity of an input optical signal and outputting an optical signal attenuated; an optical-electrical (O-E) converter that converts the optical signal to an electrical signal; an amplitude detector that outputs an output voltage based on an amplitude of the electrical signal; an optical attenuator controller that outputs a signal that controls an attenuation of the variable optical attenuator based on the output voltage; a signal detector that compares the output voltage with a signal detection threshold voltage which serves as a criterion for signal detection and provides a signal detection output; and a threshold controller that monitors the output voltage and, when a change, of the output voltage in time becomes in a stable state, changes the signal detection threshold voltage.