Provided is a waveguide guiding light to a target area, the waveguide including an input-coupling diffractive optical element (DOE) inputting the light into the waveguide, an expanding DOE expanding the light input into the waveguide through the input-coupling DOE, an output-coupling DOE outputting the light expanded in the waveguide by the expanding DOE to an outside of the waveguide, wherein the expanding DOE includes a plurality of expanding segments, and the output-coupling DOE includes a plurality of output-coupling segments.