Polarization Devices Research Articles

Doppelbrechung und Orientierungsrate der Leptonen flie�enden Protoplasmas

At defined speeds threads of protoplasm have been drawn out mechanically from a fusion of isolated gymnoplasts using an experimental arrangement described by Gerendas [3]. The polarization device, as well as the method of measuring the birefringence by means of a variable azimuth compensator of fixed retardation, viz. a rotating λ/30-mica plate, is the same as described formerly [7g-i. Then in dependence on the variable speeds of formation the protoplasmic threads show a different intensity of negative birefringence, and, what is more, it is found a distinct parallelism between birefringence, as an expression of the orientation rate of the leptones, and the speed of spinning. Always when a birefringent gel like protoplasm is put under tension, the intensity of its original birefringence or its orientation rate increases (and in the reverse order). It is to conclude that in order to analyse the leptonic structures in dependence on the effective forces, there is a great need for a quantitative approach to the anisotropy of protoplasmic constituents.

Observations of the Birefringence and Refractive Index of Synthetic Fibers with Special Reference to Their Identification

Birefringence and refractive indices of synthetic fibers are measured by the polarization color and immersion methods. These properties prove to be much more consistent and characteristic for synthetic fibers than for natural fibers and rayons, to which previous studies had mainly been confined. These fea tures can therefore be used in the identification of synthetic fibers. A simple polarizing device for making these measurments using an ordinary microscope is described.

The Formation of Fringes in a Babinet Compensator

Details are given of the appearance of the field of view when two wedges of doubly refracting material are placed in arbitrary azimuths between crossed polarizing devices. In general the field of view presents a complex pattern but simple fringe systems appear for suitable orientation of the wedges, one of which is the well-known Babinet fringe system. Theoretical relationships are derived for the intensity distribution in the general case and for the simple cases. Photographs show how the simple fringe systems are formed out of the complex cases. A use of the patterns for detecting if the wedges of a Babinet compensator are correctly mounted is mentioned.

An inexpensive polarizing device for microscopes

An inexpensive polarizing device for microscopes