Development of an optical photon-counting imager with a monolithic Geiger APD array

TL;DR

This paper presents a high-timing-resolution optical photon-counting imager using a monolithic Geiger APD array, demonstrating its capability to detect fast optical phenomena like pulsar signals with promising potential for time-domain astronomy.

Contribution

The paper introduces a novel monolithic Geiger APD array sensor system optimized for high temporal resolution in optical astronomy, with performance evaluation and initial astronomical observations.

Findings

Confirmed gain linearity and uniformity of the sensor

Successfully detected pulsar optical pulses matching radio data

Demonstrated ability to observe fast optical signals

Abstract

We have developed a sensor system based on an optical photon-counting imager with high timing resolution, aiming for highly time-variable astronomical phenomena. The detector is a monolithic Geiger-mode avalanche photodiode array customized in a Multi-Pixel Photon Counter with a response time on the order of nanoseconds. This paper evaluates the basic performance of the sensor and confirms the gain linearity, uniformity, and low dark count. We demonstrate the system's ability to detect the period of a flashing LED, using a data acquisition system developed to obtain the light curve with a time bin of 100 microseconds. The Crab pulsar was observed using a 35-cm telescope without cooling, and the equipment detected optical pulses with a period consistent with the data from the radio ephemeris. Although improvements to the system will be necessary for more reliability, the system has been proven to be a promising device for exploring the time-domain optical astronomy.