A possible non-halide route to ultralow loss glasses

Abstract Intrinsic material low-loss limits in optical fiber materials are primarily set by Rayleigh scattering losses from frozen-in density fluctuations. The theoretical expression for this loss contains a factor ϱ 2 ( ∂ϵ / ∂ϱ ) 2 , where ϱ is density and ϵ the high-frequency dielectric constant, and measures the sensitivity of ϵ to small fractional variations of density. Since ϵ is the sum of all bond polarizabilities per unit volume (plus a vacuum contribution), small density increments affect it in two ways; firstly they increase the number of bonds per unit volume and secondly they perturb the individual bond polarizabilities themselves. Although the separate contributions are smallest for halides, this paper highlights the fact that for certain compositions and structures they can be of opposite signs and that the possibility of a significant cancellation can arise for certain multicomponent oxide glasses. Existing theory, coupled with an analysis of presently very limited experimental photoelastic data available in the literature, demonstrates that this mechanism can certainly lead to a dramatic decrease in Rayleigh scattering loss (over silica) for some alkali silicate and aluminosilicate compositions, and identifies a number of other oxide glasses for which a similar or possibly enhanced effect can be anticipated, particular focus being given to the calcium aluminate family.

[1]  M. E. Lines,et al.  Scattering losses in optic fiber materials. I. A new parametrization , 1984 .

[2]  M. Lines.  Photoelastic trends from halides to pnictides by a bond‐orbital method , 1986 .

[3]  A. Osaka,et al.  The elastic constant and molar volume of sodium and potassium germanate glasses and the germanate anomaly , 1985 .

[4]  J. D. Jorgensen,et al.  Compression mechanisms in α‐quartz structures—SiO2 and GeO2 , 1978 .

[5]  H. Verweij,et al.  The structure of lithium, sodium and potassium germanate glasses, studied by Raman scattering , 1979 .

[6]  A. Wright,et al.  A neutron diffraction investigation of the structure of vitreous boron trioxide , 1982 .

[7]  G. Papatheodorou,et al.  Vibrational excitations of As 2 O 3 . I. Disordered phases , 1976 .

[8]  P. McMillan,et al.  Raman spectroscopy of calcium aluminate glasses and crystals , 1983 .

[9]  Norbert J. Kreidl,et al.  Optical and Physical Properties of Some Calcium Aluminate Glasses , 1958 .

[10]  F. W. Ostermayer,et al.  Investigation of the soda aluminosilicate glass system for application to fiber optical waveguides , 1975 .

[11]  R. J. Ginther,et al.  Light scattering in heavy-metal fluoride glasses in infra-red spectral region , 1986 .

[12]  D. Matson,et al.  Raman spectra and structure of sodium aluminogermanate glasses , 1984 .

[13]  M. E. Lines,et al.  Ultralow-Loss Glasses , 1986 .

[14]  F. L. Galeener,et al.  Raman studies of Al coordination in silica-rich sodium aluminosilicate glasses and some related minerals , 1984 .

[15]  P. B. Macedo,et al.  Rayleigh and Brillouin Scattering in K2O–SiO2 Glasses , 1973 .

[16]  G. Connell,et al.  Is there an intimate relation between amorphous and crystalline semiconductors , 1972 .

[17]  M. Lines.  The Search for Very Low Loss Fiber-Optic Materials , 1984, Science.

[18]  C. Kittel.  Introduction to solid state physics , 1954 .

[19]  Robert Zannetti,et al.  Landolt-bornstein, new series , 1974 .

[20]  Y. Kawamoto,et al.  Infrared and raman spectroscopic studies on short-range structure of vitreous GeS2 , 1982 .

[21]  R. Zallen,et al.  Photoelastic trends for amorphous and crystalline solids of differing network dimensionality , 1981 .

[22]  M. Manghnani,et al.  Adiabatic Elastic Moduli of Vitreous Calcium Alurninates to 3.5 Kilobars , 1969 .

[23]  A. Feltz,et al.  Glass formation and properties of chalcogenide systems XXXII. RDF studies on the structure of vitreous Ge2S3 and Ge2Se3 , 1985 .

[24]  J. Schroeder.  Brillouin scattering and pockels coefficients in silicate glasses , 1980 .

[25]  David K. Biegelsen,et al.  Photoelastic Tensor of Silicon and the Volume Dependence of the Average Gap , 1974 .

[26]  R. Zallen,et al.  Pressure-optical studies of GeS 2 glasses and crystals: Implications for network topology , 1982 .