The magnetic-field-induced birefringence in wedged homeotropic ferronematic liquid crystals is studied. Theoretical results for small distortions are obtained in terms of the elastic continuum theory of liquid crystals. The results of birefringence measurements are in good agreement with the predictions of the theory.

The thermal-birefringence effect in Nd(3+) -doped YAG ceramics has been investigated. The amount of depolarization induced by thermal birefringence in Nd:YAG ceramics is nearly the same as that in (111)-cut single crystals at the same Nd(3+) concentration. However, depolarization becomes larger as the Nd(3+) concentration increases, even at the same absorbed pump power.

The Strehl ratio for focusing into biaxially birefringent media with small birefringence is investigated. An analytical expression for the Strehl ratio as a function of the polarization and birefringence parameters is derived in the paraxial limit from a generalization of the scalar aberration theory. The expression agrees well with results of a numerical calculation.

The critical behaviour of the order parameter is investigated using the birefringence and Raman intensity data near the λ-phase transition (Tλ=235 K) in NH4Br. From the analysis of the experimental data using the mean field theory, the critical exponent for the order parameter is determined as β ≈ 0.5. This indicates a second order transition between the phases II (CsCl) and III (tetragonal) in...

We show that a generalized Landau theory for the smectic A and C phases exhibits a biaxiality induced AC tricritical point. Proximity to this tricritical point depends on the degree of orientational order in the system; for sufficiently large orientational order the AC transition is 3D XY like, while for sufficiently small orientational order, it is either tricritical or 1st order. We investiga...

The application area of optical fibers is quite extensive. Telecommunication applications were the primary field of fibers employment. The related area is the utilization of optical fibers for control purposes, which benefits from principal galvanic isolation between the transmitting and receiving part of the system. A minimal sensitivity of light propagation inside the fiber to electromagnetic...

Apparatus and techniques are demonstrated which allow gas phase dc electro-optic Kerr effect measurements to be made with 0.1% absolute accuracy and nanoradian sensitivity. Measurements of the electric-field-induced birefringence of a gas are calibrated against a liquid Kerr cell, which is in turn calibrated absolutely in situ. Some of the problems addressed in this work are control of stray bi...