Abstract: A holographic sight is provided having a housing that includes a plurality of holograph sight components. A laser diode mounted in the housing is configured to emit a laser light beam. The light beam is transmitted to an integrated diffraction grating and filter unit which includes a grating and a filter in a single device. The diffraction grating has a grating surface for diffracting the light beam and also diffracting unwanted ambient light transmitted into the housing. The filter is an optical filter contacting at least a portion of the grating. The optical filter is adapted to absorb at least one wavelength of the ambient light to inhibit the ambient light from diffracting into a visible spectrum that might otherwise be viewable to a user looking into the holographic sight.