Compensation of rotation effect in a combination of retarders.

In a cascaded system comprising a combination of oblique retarders, the effect of optical rotation is observed in addition to the overall retardation. This shows that the combined system does not behave as a pure oblique retarder. Analyzing such a general system using Pauli Spin matrices, it is shown that the effect of optical rotation may be completely annulled through the use of a suitably oriented retarder at the output of the cascaded system.

Achromatic quarter-wave plate using crystalline quartz.

Achromatic wave plates are ideal components for use with tunable and multiline laser systems, broadband sources, and in astronomical instrumentation. The present study deals with the design and characteristics of two different quarter-wave achromatic retarders in the 500-700 nm range, using a cascaded system of two birefringent plates. The first of these shows a variation of less than ±0.

Cultural context and impact of alcohol use in the Sundarban Delta, West Bengal, India.

Hazardous alcohol consumption is a worldwide problem with many locally distinctive features across cultures, but studies to guide policy in developing countries are notably lacking. This community study aimed to clarify local patterns of alcohol use in six villages of West Bengal, India. It considered the variety of local alcoholic preparations, who consumed them, when, and where.