An optical wavelength dispersion device includes a first substrate, an input unit formed on the first substrate having a slit for receiving an optical signal, a grating formed on the first substrate for producing a diffracted light beams from the optical signal, a first optical reflector formed on the first substrate for reflecting the diffracted light beams from the grating for outputting, and a second substrate covered on the top of the input unit and the grating, wherein the input unit, the grating and the first optical reflector are formed from a photo-resist layer by high energy light source exposure.