Reflection stratified media

The reflection and transmission coefficients for the whole stack can be extracted from the characteristic matrix of the whole stratified medium using the following relationships ... 

With the quantities computed at step 9, the reflectance and transmittance of the stratified medium are calculated as... 

In a nonlinear stratified medium both harmonic and fundamental waves undergo multiple reflections which can result in an important modification of harmonic emission especially in the case of significantly different refractive Indices of neighbouring media. Eq. (13) takes account of multiple reflections of harmonic wave on (1-2) and (2-3) interfaces associated to the fundamental wave propagating in a given direction. 

Quantitative determination of the absolute distance from the surface to a labeled cell membrane at a cell/substrate contact region can be based on the variation of F(d) with 0.(1O6) This effort is challenging because corrections have to be made for 0-dependent reflection and transmission through four stratified layers (glass, culture medium, membrane, and cytoplasm), all with different refractive indices. For 3T3 cells, Lanni et a//1065 derived a plasma membrane/substrate spacing of 49 nm for focal contacts and 69 nm for close contacts elsewhere. They were also able to calculate an approximate refractive index for the cytoplasm of 1.358 to 1.374. 

Consider an infinite array of elements oriented in the direction located in slab m of a stratified dielectric medium as shown in Fig. 3.9. As throughout [61], the elements are assumed to be excited by an external plane wave. The plane wave spectrum generated by this array can be decomposed into five wave modes as described in references 66-71. Four of these modes involve the reflection coefficient from the dielectric interfaces bounding the m, slab, while the fifth mode does not and is referred to as the direct mode. It is this mode that requires special treatment and is the reason it is revisited in detail here. The direct mode field at some point / on a test element also located entirely in slab m and oriented in the p direction may be written [66, 68]... 

Let the subscript i denote incident, r reflected and t transmitted field components for beams in isotropic media separated by a flat stratified layer of thickness T. Let the first medium, which contains the incident and reflected rays, have optical dielectric constant 1, and let the last medium have optical dielectric constant 2. Let the angle of incidence within the first medium be Fig. 1). SnelFs... 

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