![]() This method is valid for any set of layers. Where we introduced the real parts of the $k$-vectors to consider the case of total internal reflection, in which the propagation angle is imaginary and the transmission becomes zero. Assuming that the plane wave wave propagates in the positive $z$ direction through a medium with refractive index $n$, at an angle $\theta$ with respect to the $z$ axis, the magnitude of the electric field can be described as: ![]() Of course, the real electric field of the wave is only the real part of this magnitude, but considering the complex number simplifies the calculations as trigonometric functions become exponentials, which are easier to handle. FreeSnell is an application of the SCMScheme implementation and the WBB-tree database package. We will consider the electric field as a complex numbers whose phase tells us about the phase of the wave. The FreeSnell Thin-Film Optical Simulator FreeSnellis a program to compute optical properties of multilayer thin-film coatings. However, this method, being more intuitive as the scattering and propagation matrix are distinct, makes it more convenient to generalize the problem to other situations, therefore this is the one we will apply. The main disadvantage of this method is that it requires two matrices per layer. This way, apart from the matrix required for the propagation through every layer, every interface also requires a matrix which contains the Fresnel coefficients of reflection and transmission. It is the method used, for example, in Yeh’s book. Another method, which is more intutive, propagates the magnitudes of the electric fields propagating to the left and to the right. Using the continuity equations for electromagnetic waves, one can assign just one matrix to each layer, and the job is done. In one method, which the one used used in Born
0 Comments
Leave a Reply. |