An automatic optical imaging system for birefringent media

A new optical microscope imaging system is described. The instrument is capable of producing coded colour images of an optically birefringent material, where the colour represents either \sin delta\, a function of the optical retardation; phi, the orientation of a section of the optical indicatrix; or I-o, the transmittance, at any place within the image. Thus the contrast normally seen in a standard crossed-polars experiment is separated out into its components. The technique is both qualitative and quantitative. Examples of the application of this system to crystals, a rock section and a biological specimen are given.