Holographic measurements of refractive-index changes

Abstract
We consider here a new method for identifying changes in the index of refraction. A birefringent material was illuminated directly, without a diffuser, and recorded holographically in one step. An unpolarized TEM00 continuous-wave laser, which emits elliptically polarized light on the time-average scale, was applied in this experiment. With such a holographic recording system three types of reconstruction for the same object are possible, off-axis with laser, off-axis with white light, and on-axis with laser (Gabor hologram). Properties of the holographic recording system and reconstruction of images by the first two of these methods are discussed.