In this paper, using the Helmholtz wave equation and the tunneling time of a photon [I] through a index of refraction barrier, the reflktion delay time and reflection coefficient calculated and analytical expression for these quantities are introduced. It p,edicts that, the reflection delay time and coefficients depends on the refraction indeq the thickness of barrier, the incident angle, and the incident wave frequency. Using these relations, we obtain the light penetration depth as well as horizontal shifts for reflection component of incident light to the interface of two media as shown in Fig.(l-a). Our results completely describe the nature of Goos-Hanchen shifts in planar optical slab waveguides as a common device in optical integrated circuits (OIC). Also. the experimental data and our prediction completely close together. 1. Jntroduction-In recent years, the tunneling time of a particle passing through a potential barrier opaque classically has recently been one of the most striking subject. Most of these works are based on the numerical and analytical analysis of Schrodinger equation with some initial condition on the wave packets [2-41, and have been approved experimentally [5-8]. So the tunneling time of a particle can be obtain in different ways [4,14]. The analogy between quantum tunneling of particle and evanescent electromagnetic wave found in a lowdielectric constant region separating two regions of high dielectric constant, can be considered and one can find a suitable approach for tunneling time of photon from this classically forbidden region [I]. With reference to Fig.(l-a), a light beam impinges from a dielectric medium with index n, onto a dielectric slab waveguide with index nz < n, . If the incident angle is greater than the critical value 0, = sin-' (A) , all of the light beam must be reflected, but in practice some part of it tunnels through the slab and emerges in the second dielectric medium with index n, and another part of this light beam reflected. The reflected component, from practical point of view, have the horizontal shifts named Goos-Hanchen shifts [19], n "1which was explained as penetration of light into the forbidden region. Using the tunneling phenomena, we propose the analytical relation for reflection delay time, the reflection coefficient and the penetration depth. Based on these results, we calculate the horizontal shifts and show that the predicted our results completely describe the Gws-Hanchen shift. Organization of this paper are as follows:In section 11, the basic idea for reflection delay time and the reflection coefficient discussed. The Gws-Hanchen shifts based on the reflection delay time discussed in section 111. Finally paper is ended with a conclusion, including the discussion about simulated results.
II. Reflection Delay Time and Coeftlcient-We study onedimensional problem in which wave packet propagates along one direction say the z -axis. Let us consider a wave packet moving along z-axis incident on a region [ O , U ] with a refractive index n(z), as dep...