Excelitas Canada, Inc.

Frederic Laforce

Almar Palonpon

Ralph Kig-I

Jinhan Ju

A photoelectric receiver circuit for converting an optical signal to an electrical signal is presented. The receiver includes a photodetector connected between a transimpedance amplifier input and a high voltage supply providing a bias voltage to the photodetector. A high voltage supply variation sensing element is connected between the high voltage supply and a current controlled current source, where the current controlled source output is connected to the input of the transimpedance amplifier. A current limiter is connected between the high voltage supply and a high voltage source. The photocurrent passing through the current limiter lowers the high voltage supply and is detected by the sensing element. Current from the sensing element is processed at the input of the transimpedance amplifier to minimize the current into the transimpedance amplifier, limiting the saturation of the amplifier, thus improving recovery time when a high optical power pulse impinges the photodetector.

Optical receiver with fast recovery time

A device and method to protect an APD or SiPM optical receiver against photodetector voltage supply variation is presented. A differential trans-impedance amplifier includes one input connected to the photodetector and the other input connected to a high voltage supply variation sensing device. The sensing element includes a circuit replicating the impedance of the photodetector.

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Coteau-du-Lac, Canada

Frederic Laforce