Sumitomo Electric Industries, Limited

Sumitomo Electric Device Innovations, Inc.

Tetsu Murayama

Moriyasu Ichino

The integrated optical receiver module includes a plurality of PDs each converting an optical signal to a current signal, and outputs a current signal selected from a plurality of current signals. The RSSI circuit converts the current signal into a voltage signal, outputs a first amplified signal obtained by amplifying the voltage signal by a first gain, and outputs a second amplified signal obtained by amplifying the voltage signal by a second gain larger than the first gain. The MCU outputs a first selection signal to the integrated optical receiver module to acquire intensity of the first amplified signal with respect to all of the current signals in a predetermined order, outputs a second selection signal to the integrated optical receiver module to acquire intensity of the second amplified signal with respect to all of the current signals in the ascending order of the acquired intensity of the first amplified signal, and derives intensity of each of the optical signals from the acquired intensity of the respective second signals.

Optical receiver and detection method

A method to monitor an output of an APD is disclosed. The method includes steps of, (a) measuring dark currents of the APD at several temperatures in advance to a practical operation of the APD, (b) measuring an output current of the APD by illuminating the APD practically at a measured temperature, (c) estimating a dark current at the measured temperature from measured dark currents, and (d) subtracting the estimated dark current from the output current.

Method for measuring optical input power by avalanche photodiode

The present invention is to provide an optical receiver that prohibits the miss-detection of the recovery from the LOS (Loss-Of-Signal) state. The optical receiver includes an light-receiver device for converting an optical input signal to a photo-current, a pre-amplifier for converting this photo-current into a voltage signal, and a LOS detector to detect the LOS state based on the output from the pre-amplifier. The LOS detector includes a bottom hold that detects and keeps the bottom level of the output from the pre-amplifier and the comparator that sets the output thereof when the output from the bottom hold exceeds the threshold V.

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Yokohama, Japan

Tetsu Murayama