TABLE OF CONTENTS The successful design of an optical experiment requires the correct choice and installation of its component parts. This chapter discusses the principles of operation, fabrication, and alignment of the most common optical elements.
For light in the visible range, the most commonly used, high-quality polarizers use bire-fringent crystals in combination with the phenomena of total internal reflection to produce linearly polarized light. The Glan-Thompson polarizer is one such design [51] and is pictured in Figure 9.1. This polarizer consists of two triangular pieces of a transparent crystal arranged in the square configuration shown below with an air gap existing along their mutual interface. The crystalline material (calcite is often used, for example) is characterized by two indices of refraction, n e and n o. For the polarizer in Figure 9.1, therefore, light polarized along the y axis will see the refractive index, n e, whereas horizontally polarized light will respond to n o.
Such a crystal is "double refracting" since the two values of the refractive index will cause the two polarizations to propagate along different paths. Separation of the two polarizations occurs at the interface where the horizontally polarized light is totally internally reflected. The vertically polarized light, on the other hand, is transmitted across the interface where the second half of the polarizing cube returns this polarized beam to its original path. Typical extinction ratios for this type of polarizer are greater than 10 3 and as...
