Staggered folding optical path structure of small-sized grating monochromator with high spectral resolution

The invention discloses a staggered folding optical path structure of a small-sized grating monochromator with high spectral resolution, belonging to the technical field of spectral analysis instruments. The optical path structure comprises an entrance slit, a collimator objective lens, a plane grating, a convergence objective lens, an exit silt, a rotary table, a first turning reflector and a second turning reflector; a light beam emitted by the entrance silt is radiated to the collimator objective lens after being turned through the first turning reflector, dispersed and split by the plane grating after being collimated, turned by the second turning reflector after being converged through the convergence objective lens, and focused to the exit silt, so that quasi-monochromatic light is obtained. The staggered folding optical path structure is compact in structure, small in size, light in weight, and simple to process, assemble and calibrate. The volume in the length direction of the apparatus is effectively compressed; cylindrical reflectors are adopted as turning reflectors, so that the system astigmatism can be effectively reduced and the energy concentration degree of the exit spectrums of the apparatus is improved. A system has symmetrical photometric characteristics, so that the off axis aberration can be effectively eliminated and the imaging quality is improved.