Experimental investigation of far-field diffraction by means of normally and non-normally illuminated elliptical apertures of wavelength dimension

Far-field diffraction resulting from elliptical apertures of different sizes is measured. Both normal and oblique angles of incidence on the apertures are investigated. Diffraction patterns from apertures with dimensions much greater than the wavelength agree with the existing theory. However, new diffraction patterns have been found when using an aperture of wavelength dimension.