In an amplitude grating system of small grid pitch, the diffractive light is the main cause to deteriorate the contrast and sinusoidal property of Moiré signals.

The authors show that using the half-wave strip method to deduce the bright and dark fringe conditions of Fraunhofer grating diffraction is simpler than the amplitude vector method.

We inscribed surface relief grating on the thin films using Point-by-Point method and amplitude mask method (the amplitude mask was taken place by grating roll film manufactured by ourselves).