EXPERIMENT #5BREWSTER’S ANGLE AND OPTICAL PROPERTIESI. OBJECTIVE Light is an electromagnetic wave in the terahertz (1015 cycles/sec) frequency range. In this lab you will design an experiment to measure the reflection and transmission of light at different angles of incidence from several materials for two polarizations, find the Brewster angle for a transparent material, and estimate the optical constants of the materials. II. EQUIPMENT REQUIREDDiode laser with AC power adaptor and switch.Photo diode detectorPlexiglass protractor (with diode laser holder and detector holder)Polarizing filmElectronics to make optical detector:Small proto-board phototransistor 741 op-amp 9-volt batteries (4)electrical components, wires, wire-strippers, etc.Samples to measure optical propertiesTransparent acrylic (plexiglass) half-disk Piece of polished silicon wafer on half-diskPolished stainless steel on half-diskIII. THEORY A. Snell’s LawWhen light is transmitted across the boundary between two materials with different velocities of light, the direction of propagation of the light wave changes. To see this, consider the diagram in Figure 1 below. We assume that the incident, reflected, and transmitted light waves are represented by plane waves:. (1)Here is the position vector and is the wave propagation vector – sometimes written as. (The actual electric field is found by taking the real part of the complex electric field.) The direction of the wave vector is the direction of propagation of the wave, and the magnitude of is given by where v is the velocity in the medium with dielectric permittivity e and magnetic permeability µ. If the wave is propagating in thedirection, for example, and the wave becomes one-dimensional. Pre-Lab Exercise 1: Derive this result from Eq. 1. Figure 1: Wavefront incident on boundary between two dielectrics If the electric fields are in the x-z...
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