Light path structure of small asymmetric high-spectrum-resolution grating monochromator

The invention discloses a light path structure of a small asymmetric high-spectrum-resolution grating monochromator, and belongs to the technical field of spectral analyzers. The structure comprises an entrance slit, a collimator objective, a plane grating, a convergence objective, a turning reflector, an exit slit and a rotary table, wherein light beam sent by the entrance slit is irradiated to the collimator objective for collimation and is dispersed and split by the plane grating after collimated, the dispersed light beam is converged by the convergence objective and focused to the exit slit after the light path is turned by the turning reflector, and accordingly, collimated monochromatic light is obtained; and the plane grating is fixed on the rotary table, and monochromatic light with different wavelengths is output at the exit slit by rotating the grating through the rotary table. The system structure is compact, the size is small, the weight is light, and processing, assembling and calibration are simple; the convergence objective can obtain a longer focal length, so that spectrum line dispersion of the monochromator is remarkably improved; and the light path is folded in an instrument by the turning reflector, the size of the instrument is effectively reduced, system astigmatism can be effectively reduced, and the energy concentration ratio of emergent spectrum of the instrument is increased.