Control of the Birefringence Dispersion of an Optical Polymer by Doping with an Inorganic Crystal

Abstract

We extend our previous formulation of low-energy QCD in terms of an effective lagrangean containing operators of dimensionality d ≤ 6 constructed with pseudoscalars and quark fields, describing physics below the scale of chiral symmetry breaking. We include in this paper the vector and axial-vector channels. We follow closely the Extended Chiral Quark Model approach and consistently work in the large-N c and leading log approximation and take into account the constraints from chiral symmetry and chiral symmetry restoration. The optimal fit of all parameters gives further support to a heavy scalar meson with a mass ∼ 1 GeV and a value of the axial pion-quark coupling constant g A 0.55 to 0.66, depending on some assumptions concerning the Weinberg sum rules.

Compensation and control of the birefringence of polymers for photonics

“…22 Although the absolute value of the birefringence of polymers generally decreases with increasing wavelength, retardation films with a reverse birefringence dispersion in which the absolute value of the birefringence increases with increasing wavelength are required. Some types of retardation films prepared by mixing various components have been reported.…”

“…Figure 10 shows the design concept for a polymer film with a reverse dispersion prepared by doping the polymer with SrCO 3 crystals, solvent casting to form a film and then drawing the heated film. 22 By this method, a cycloolefin copolymer film containing SrCO 3 nanocrystals that exhibited reverse dispersion was fabricated, as shown in Figure 10. The orientation of the SrCO 3 nanocrystals was confirmed by means of transmission electron microscopy.…”

“…The nanocrystals were oriented immediately after casting, and then the orientation was enhanced by uniaxial heat drawing (Figure 11). 22 Polymer chains were also oriented by uniaxial heat drawing. Therefore, the ratio the degree of orientation degrees of the nanocrystals to that of the polymer chains can be controlled by adjusting the conditions for the casting and for the uniaxial heat drawing.…”

“…As shown in Figure 12, the transmittance of the cycloolefin copolymer film containing 5wt% SrCO 3 crystals was 89.1% at the wavelength of 550 nm, whereas that of the undoped film was 90.7% at the same wavelength. 22 Poly(MMA/BzMA¼92/8 (wt)) film doped with 5.0wt% of SrCO 3 crystals was prepared to investigate the effect of the SrCO 3 crystals on photoelastic birefringence. 25 The photoelastic coefficient of the polymer film was about À1.1Â10 À12 Pa À1 .…”