A grating coupler with a period of 0.56 μm has been built on the glass substrate by duplicating technique from a master grating. It has been experimentally observed that laser beam can be coupled into the waveguide film from above cair, as well as from below (substrate). The mode excited in the waveguide can be varied by varying the angle of incidence of laser beam, and light wave of different diffraction order can also be coupled into guide wave mode. An input coupling efficiency of 66.0±0.5% has been achieved experimentally.