title: Optical and physical parameters of Plexiglas 55 and Lexan.
abstract: 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.
authors.forename: R M
authors.initials: RM
authors.lastname: Waxler
authors.forename: D
authors.initials: D
authors.lastname: Horowitz
authors.forename: A
authors.initials: A
authors.lastname: Feldman