Modified concentric spectrograph, a method for diffracting a method and two light beams to distribute the light

摘要

PROBLEM TO BE SOLVED: To obtain a high-performance concentric spectrograph that has a high stray light exclusion rate and disperses multiple-color light by providing a diffraction grating with a recessed surface, a lens, an incidence port, and an emission port. ;SOLUTION: An enhanced concentric spectrograph includes at least four optical elements, namely an incidence port 205, an emission port 211, a lens 215, and a recessed surface diffraction grating 220. The first element, namely the recessed surface diffraction grating 220, contains a recessed surface grating surface 221, an optical shaft 203, and a meridian plane 225. The meridian plane 225 has two sides. The second optical element is the lens 215 in flat-projecting surface shape containing a flat surface and a projecting surface 217. The third and fourth optical elements are an incidence port 205 and an emission port 211. Then, the incidence port 205 and the mission port 211 are essentially arranged outside the meridian plane 225 and at a different side. In the case of an enhanced spectrograph 200, negative primary and secondary beams are not essentially mixed at the emission port 211.;COPYRIGHT: (C)1998,JPO