Abstract: This paper has made an exhaustive derivation of Franuhofer diffraction of double slits with different widths and Gaussian beams in terms of the Kirchhoffs theory. The influence of double slits with different widths,the Gaussian beams and the laser spot radius on the intensity distribution of double slits diffraction is analyzed by the experimental and numerical studies. The experimental phenomenon of double slits diffraction is discussed through theoretical analysis and experimental demonstration.

Key words: Fraunhofer diffraction of the double slits, Gaussian beam, light intensity distribution