Abstract: ZrO₂ color separation grating (CSG) was devised by photosensitive sol-gel binary optics method. The grating’s refractive index was measured with ellipsometer, and its structure parameters were acquired by white light interferometer. These values were input to a computation program to calculate the grating’s theoretical diffraction efficiency. Its color separation performance at aimed wavelength was also tested experimentally. The results show that the grating’s zero order efficiency is closed to 70% for 355 nm, while about 13% of the light is not separated with respect to 1 064 nm and 532 nm. Theoretical results fit the experiments well.