Absolute linearity measurement of photodetectors using sinusoidal modulated radiation

Abstract

A method is presented for characterizing the linearity of photodetectors based on time-domain analysis of response to sinusoidal excitation. Nonlinearity is quantified solely from the output distortion. Relative response is converted to absolute response by including two calibration points. For low signal level, one calibration point is required, while using dark current as the second point. The response is mapped over a wider range using a series of overlapping sinusoids for calibration transfer. The method is demonstrated with a relatively linear photodiode and a nonlinear phototransistor. A Michelson interferometer is used to generate sinusoidal modulation of a laser source. Results demonstrate the potential of the proposed technique.

Bulletin of the Polish Academy of Sciences: Technical Sciences

“…Responsivity measurements are essential for characterizing photodetectors. During this procedure, the tested detector works in the linear operation range [27]. The precise determination of its spectral characteristic makes it possible to estimate the power of the incident radiation based on the output signal.…”

Experimental studies of error compensation for optical signal coordinate determination by double synthesized aperture

“…Однако в условиях неравномерной фоновой засветки, характерной для формирования сигнала с помощью оптической щели, сохраняется погрешность координатоуказания, обусловленная нарушением линейности люкс-амперной характеристики датчиков при воздействии на p-n-переходы мощной засветки [13,14]. Такая ошибка присуща всем типам ПЧД, и возможность уменьшения ее связана или с повыше-нием линейности люкс-амперной характеристики приборов в динамическом диапазоне 5-6 порядков, или с возможностью симметризации влияния фоновой помехи на значение фототока полезного сигнала [15,16].…”