MIRROR AUTOCOLLIMATOR SPECTROMETER Russian patent published in 2015 - IPC G01J3/16 G02B17/08 

FIELD: physics.

SUBSTANCE: spectrometer consists of inlet slit, objective lens and flat reflecting diffraction grating. Inlet slit is located in focal plane of said objective lens and shifted relative to its optical axis. Objective consists of three mirrors. First mirror is the off-set ellipsoid-shape mirror with optical power some 1.5-2.5 times higher than that of the third mirror. Second spherical mirror features negative power some 2.5-3.5 times higher than that of the third mirror. Third mirror is composed of the off-axis hyperbolic fragment with positive optical power approximating to that of the entire objective. Spacing between the first, second and third mirrors is 1.5-2 times smaller than focal length of the entire objective. Optical axes of the mirrors are aligned with the objective optical axis. Parallel-side plate is located ahead of image plane and features refractive index of 1.4-1.6 and thickness of 0.005-0.02 of the objective focal length. Diffraction grating features the lustre angle calculated for the 1^st order spectrum.

EFFECT: higher quality and homogeneity of the image.

3 dwg, 1 tbl