Normalized Spectral Responsivity Measurement of Photodiode by Direct Method Using a Supercontinuum Laser Source

Abstract

Light detectors such as photodiodes and phototransistors are fundamental elements that compose imaging sensors and cameras devices. The photocurrent generated by photodiodes depends on the energy of light that is absorbed by semiconductor material, describing an important characteristic of this kind device. We present an optic instrumentation for measurement of normalized spectral responsivity of light detectors. The optics is composed by a single-grating monochromator, converting lens, a slit and a beamsplitter. Supercontinuum lasers provides a high-stability beam with ultra-broadband white-light spectrum. High spectral purity is achieved with only monochromator and the measurements are performed in terms of spectral power measured through a calibrated spectrometer. Uncertainties are examined at carefully for a specific confidence level considering Type A and Type B evaluations.