Birefringence intrinsic

The large intrinsic birefringence of the sarcoplasmic reticulum [143] and the polarized attenuated total reflectance FTIR spectroscopy data obtained on oriented films of sarcoplasmic reticulum [144] indicate that a sizeable portion of the secondary structural elements are arranged perpendicularly to the plane of the membrane in a manner reminiscent to the structure of bacteriorhodopsin [145-148]. 

In particular most of the early studies on CPL were based on the incorporation of a luminescent achiral chromophore in a chiral nematic or cholesteric liquid crystal. Chiral nematic liquid crystals (CNLC) are intrinsically birefringent and exhibit a helical supramo-lecular architecture, which is characterized by the pitch length p (Figure 5.11). 

Thurston, G.B., Peterlin,A, Influence of finite numbers of chain segments, hydro-dynamic interaction, and internal viscosity on intrinsic birefringence and viscosity of polymer solutions in an oscillating laminar flow field. J. Chem. Phys. 46, 4881-4885 (1967). 

However, as soon as a finite contribution of the form effect is contained in the value of Maxwell constant, the said conditions are no longer superfluous. In fact, the form effect is highly concentration dependent in the range of low concentrations (138, 63), and has a shear rate dependence different from that of intrinsic birefringence and viscosity. In other words, due to the presence of the form effect, the ratio of Maxwell constant and intrinsic viscosity can no longer be interpreted as twice the stress-optical coefficient in the sense of Chapter 2. 

The polarizability tensor, a, introduced in section 4.1.2, is a measure of the facility of the electron distribution to distortion by an imposed electric field. The structure of the electron distribution will generally be anisotropic, giving rise to intrinsic birefringence. This optical anisotropy reflects the average electron distribution whereas vibrational and rotational modes of the molecules making up a sample will cause the polarizability to fluctuate in time. These modes are discrete, and considering a particular vibrational frequency, vk, the oscillating polarizability can be modeled as... 

Burnett, Z.H. Levine, and E.L. Shirley, Hidden in plain sight calcium fluoride s intrinsic birefringence, Photon. Spectra, pp. 88 92 (Dec. 2001). 

Intrinsic birefringence in calcium fluoride and barium MRF polishes calcium fluoride to high... 

The results of measurements of intrinsic birefringence permit estimation of chain segment stifi iess in an oriented polymer chain. Birefringence is among the techniques used to evaluate molecular orientation in polymers. Figure 2.27 shows changes in birefrin-genee of PVC film on its extension at 90"C. Data in the paper show that the... 

T. Todorov, L. Nikolova, andN. Tomova. Polarization holography. 2 Polarization holographic gratings in photoanisotropic materials with and without intrinsic birefringence. App/. Opt., 23 4588-4591, 1984. 

Absorption coefficients of about 0.5 pm" allow imaging of 200 nm thick films. At present, however, there are problems concerning pattern development. Moreover, difficulties regarding lenses and masks have to be resolved. As yet, Cap2 is the only feasible lens material, since fused quartz is not transparent at 157 nm. However, Cap2 is crystalline and, therefore, intrinsically birefringent. Consequently, lenses have to be made from elements with different crystal orientations. 

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