No.3（2008）10.Development of a Relative Spectral Responsivity Measurement Method

Hirotaka Nakamura, Toshihide Iwanaga, Tetsuo Yamamoto, Toshiharu Nakajima

The development and use of light emitting diodes (LEDs) in illumination have been increasing due to the recent development of solid state lighting, and consequently photometric characterization measurement requests - for example: illuminance, luminous intensity distribution, and total luminous flux - of LED lighting have also increased. For the photometric characterization measurement of light sources such as LEDs, fluorescent lamps, and incandescent lamps, it is important to precisely measure spectral responsivity and to maintain a spectral responsivity measurement system. The spectral responsivity of a photodetector (its sensitivity at each wavelength) is an important characteristic, essential in the accurate measurement of the emission spectrum of light sources. Spectral responsivity measurement techniques are equally useful in photodetector assessment and in the evaluation of newly fabricated photodetectors. We propose a relative spectral responsivity measurement method for the spectral range from 1150 nm to 2500 nm. In this study we report on the evaluation results of photodetectors, a correction method of the spectral responsivity by reflectance on the photodetector surface, and a relative spectral responsivity measurement using an optical power meter or radiometer.

Keywords

spectral responsivity, photodetector, standard detector

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