Patent ID: 11561131

Abstract:
A determination method determines a difference voltage between a breakdown voltage and a bias voltage. A temperature compensation unit provides temperature compensation for the gain of the APD by controlling the bias voltage based on the difference voltage. The bias voltage is “Vr”, and the gain of the APD to which the bias voltage is applied is “M”. The slope and intercept of the regression line having “(1/M)×(dM/dVr)” as an objective variable and “M” as an explanatory variable in data indicating the correlation between the bias voltage and the gain are obtained. “ΔV” calculated by substituting the slope into “a” in the Equation (1), substituting the intercept into “b” in the Equation (1), and substituting a gain to be set in an avalanche photodiode of a light detection device into “Md” in the Equation (1) is determined as the difference voltage.