The theoretical model of optical waveguide impulse response

From the known transfer function of optical propagation, its impulse response function has been derived out. The resulted diffraction formula, which needn´t be based upon the assumption of the Sommerfeld radiation condition and can then be applied to any infinite wave front case, shows the complete equivalence of the diffraction theory of Fourier optics with the Sommerfeld´s scalar diffraction theory. The existence of the general cross radiation condition, which closely depends on the specific Green function employed by Sommerfeld but more general than the Sommerfeld radiation condition for the validity of Sommerfeld´s theory, has been verified for a consequent wave field from any infinite wavefront propagating forward.