  We have analytically obtained the theoretical results for the
Rayleigh-Sommerfeld (R-S) scalar diffraction by apertures, such as single-slit,
double-slit, grating and circular aperture, moving at relativistic speeds with
the velocities perpendicular to the direction of incidence. We also have
studied diffraction by a single-slit of oscillatory shutter. Our study would be
significant in probing the relativistic transverse Doppler effect on the
intensity pattern of the diffracted field.
