Spectrometry measuring apparatus

• Main Author: Araki, Nobuhiro
• Format: Patent
• Language: English
• Published: 22.07.2003

The present invention relates to a spectrometry measuring apparatus of a spectrograph type using a concave holographic diffraction grating manufactured by a holographic method. In a spectrographic type spectrometry measuring apparatus employing a concave holographic diffraction grating or a replica thereof, a small-size and light-weight spectrometry measuring apparatus having a high reliability with a spectrum position does not move in a photo detector plane in spite of an occurrence of a temperature change. This measuring apparatus is composed of a light-condensing device, a concave holographic diffraction grating or a replica thereof, and a telecentric correction lens for condensing a diffracted light from the diffraction grating telecentrically on the spectrum condensing plane. In this constitution, the spectral ray enters vertically to the spectrum focusing plane, and if the photo detector is moved in the optical axis direction due to a temperature change, the spectrum is not moved on the photo detector surface, and it is not necessary to calibrate an optical element due to an ambient temperature change.