Deane Horowitz

Optical and physical parameters of Plexiglas 55 and Lexan

The following parameters have been obtained for Plexiglas 55 and Lexan: refractive index n at 486.1 nm, 589.3 nm, and 656.3 nm, the thermooptic constant dn/dT at 632.8 nm, the linear thermal expansion coefficient; the photoelastic constants q(11), q(12), p(11), and p(12); and the elastic moduli c(11), c(12), s(11), and s(12). The experimental value for the density derivative of refractive index rho(dn/drho)T deviates by only a small amount from the value calculated from the Lorentz-Lorenz equation. This is the expected result for molecular solids. The density variation with temperature is the dominant contribution to dn/dT.

OPTICAL ACTIVITY AND FARADAY ROTATION IN BISMUTH OXIDE COMPOUNDS

The optical rotatory power and Faraday rotation were measured in crystals of 17Bi2O3: Ga2O3, 7Bi2O3: ZnO, Bi12TiO20, Bi12GeO20, and Bi12SiO20 in the wavelength range 400 to 700 nm at room temperature. Our crystals were enantiomorphs of those reported previously. The large Verdet coefficients indicate that these crystals are potentially useful as magneto‐optic modulator materials.

Mechanisms for self-focusing in optical glasses

The relative contributions of the Kerr, electrostrictive, and thermal effects to the self-focusing thresholds of borosilicate crown glass, fused silica, and dense flint glass have been estimated from an analysis of damage-threshold data for linearly polarized and circularly polarized radiation. The measurements were made with a Nd:glass laser operating in the TEM 00 mode with a temporal pulsewidth of 25 ns. The Kerr effect appears to be the largest effect. The thermal effect is also significant. The electrostrictive effect is smallest. Reasonable values of the absorption coefficient are calculated from the thermal contribution. The results are in qualitative agreement with the work of others.

Refractive Index of Cuprous Chloride

The refractive index of single-crystal CuCl at room temperature was measured in the wavelength range 0.42–1.2 μm using a V-block refractometer. The range of wavelengths was extended to 22 μm by measuring the wavelength dependence of interference fringes in thin polished plates. A dispersion equation was fitted to the data over a limited wavelength range.

Dispersion of the Piezobirefringence of GaAs

The piezobirefringence of GaAs shows a large anomalous dispersion near the absorption edge and exhibits a nonlinear stress dependence. The coefficient π11–π12 reverses sign. Lowering the temperature from 298° to 77°K shifts the dispersion curves +0.088 eV, which is approximately equal to the shift of the energy gap with temperature. These effects, which have not been observed previously in GaAs, are related to the stress dependence of transitions associated with the absorption edge and resonance photoelasticity described by Kaplyanskii and Lozovskaya.

Photoelastic constants of germanium

The photoelastic constants of Ge have been measured at 3.39 and at 10.6 μm. Our stress‐birefringence data join smoothly to earlier stress‐birefringence data at other wavelengths. The acousto‐optic figure of merit M2, computed from our data, agrees well with M2 determined for commercial acousto‐optic devices. However, our data disagree with some earlier measurements of M2, the elasto‐optic constants pij, and the change of refractive index with hydrostatic pressure dn/dP.

Optical Materials Characterization, Final Technical Report February 1, 1978-September 30, 1978

Data obtained as part of the Optical Materials Characterization Program are summarized in this report. Room temperature values of refractive index as a function of wavelength are presented for the following materials: commercially grown KCl, reactive atmosphere processed (RAP) KCl, KCl nominally doped with 1.5% KI, hot forged CaF2, fusion cast CaF2, CaF2 doped with Er (0.001% to 3% Er), SrF2, chemical vapor deposited (CVD) ZnSe (2 specimens), and ZnS (CVD, 2 specimens). Data for the thermo-optic constant (dn/dT) and the linear thermal expansion coefficient are given for the following materials over the temperature range -180 degrees C to 200 degrees C: Al2O3, BaF2, CaF2, CdF2, KBr, KCl, LiF, MgF2, NaCl, NaF, SrF2, ZnS (CVD), and ZnSe (CVD). The piezo-optic constants of the following materials are presented: As2S3 glass, CaF2, BaF2, Ge, KCl, fused SiO2, SrF2, a chalcogenide glass (Ge 33%, As 12%, Se 55%) and ZnSe (CVD).

Temperature dependence of Szigeti effective charge of alkali halides

Abstract The second Szigeti relation was used to obtain the temperature dependence of the Szigeti effective charge, es. The results are discussed in the framework of the deformation dipole model. Recent experimental data are used to show that the volume derivatives of es of most ionic solids are positive, thus providing evidence that the deformation dipole model is qualitatively valid.

High-index optical materials for 193nm immersion lithography

We report on our comprehensive survey of high-index UV optical materials that may enable extension of immersion lithography beyond a numerical aperture of 1.45. Band edge, refractive index, and intrinsic birefringence (IBR) at 193 nm determine basic viability. Our measurements of these properties have reduced the list of potential candidates to: ceramic spinel, lutetium aluminum garnet, and a class of germanium garnets. We discuss our measurements of the intrinsic properties of these materials and assess the present status of their material quality relative to requirements. Ceramic spinel has no significant IBR, but transmission and scatter for the best samples remain at least two orders of magnitude from specifications. Improving these would require a major development effort. Presently available lutetium aluminum garnet has material quality much closer to the specifications. However, the IBR is about three times the required value. The germanium garnets offer the possibility of a lower IBR, but a suitable candidate material has yet to be established.

Photoelastic constants of potassium chloride at 10.6 μm

The piezooptic constants of pure KCl and KCl doped with KI have been measured in the visible and at 10.6 microm by interferometric and polarimetric techniques. The dispersion of the elastooptic constants, computed from the piezooptic constants, differs from the dispersion calculated from a theory based on a two-oscillator model of the refractive index.