An equal-period plane diffraction grating fabricated through electron beam lithography line-by-line method was designed and applied to the experiment of angle sensitivity testing. The size of the fabricated grating region was [Formula: see text] mm and the period was 1526 nm. The incident light was transmitted via the Y-type fiber to collimator lens fixed on the angle disc, which can be adjusted to change the incident light angle. The diffraction spectra generated by the incident light irradiating the grating surface were collected by the optical spectrum analyzer. In this experiment, the incident light angle was fixed at 25[Formula: see text]. When the spot moved horizontally by 50 mm, the diffraction wavelength was basically unchanged. When the incident light angle was adjusted from 15[Formula: see text] to 31[Formula: see text], the diffraction wavelength was changed from 834.03 nm to 1589.80 nm, the angular sensitivity was 47.508 nm/[Formula: see text], and the linearity was 0.9998.
