Abstract: The curved fork-like grating is provided where curves formed by all points in the same relative positions in respective periods are distributed to be curved and fork-like, so that incident light irradiated on the curved fork-like grating is converted into Bessel-Gaussian light. Such a curved fork-like structure can be achieved by various gratings, such as a metal grating, a dielectric grating, or a metal and dielectric hybrid grating, without affecting their intrinsic characteristics, such as a diffraction efficiency, a use band, a diffraction angle, and a polarization characteristic except that a diffraction light field carries a high-order Bessel phase. Compared with a method for obtaining Bessel-Gaussian light in the prior art, the curved fork-like grating provided by the present invention is simpler in light path and appropriate for a wide band.