Chemistry:Fluorophosphate glass
Fluorophosphate glass is a class of optical glasses composed of metaphosphates and fluorides of various metals. It is a variant of phosphate glasses. Fluorophosphate glasses are very unusual in nature. Fluorophosphate glasses have ultra-low theoretical loss of 0.001 dB/km, longer fluorescent lifetime of rare earths, lower coefficient of thermal expansion of ~13×10−6/°C.[1] Some fluorophosphate glasses are used as low dispersion glasses. Some show anomalous partial dispersion.[2] One such glass is composed of Ba(PO3)2, Al(PO3)3, AlF3, and alkaline earth fluorides MgF2, CaF2, SrF2, and BaF2, with possible addition of titanium, sodium, potassium, and/or hydrogen. The components by wt.% are 0.5–3% Mg, 8–10% Ca, 12–20% Sr, 9–12% Ba, 7–9% Al, 5–9% P, 8–12% O, and 35–38% F.[3]
Some doped fluorophosphate glasses are used in laser technology. They are attractive here for their small refractive index nonlinearity.[4] Rare-earth elements are popular dopants. One of the applications is for optical amplifiers.
Exotic dopants like fullerenes[5] and quantum dots can be employed.[citation needed]
Tungsten-doped tin-fluorophosphate glasses (SnO-SnF2-P2O5) can be used for hermetic sealing of organic light-emitting diodes and other devices.[6]
See also
References
- ↑ Stokowski, S. E; Martin, W. E; Yarema, S. M (1 July 1980). "Optical and lasing properties of fluorophosphate glass". Journal of Non-Crystalline Solids 40 (1): 481–487. doi:10.1016/0022-3093(80)90123-4. Bibcode: 1980JNCS...40..481S.
- ↑ "Optical fluorophosphate glass having anomalous positive partial dispersion and process for its production" US patent 4859635
- ↑ "Optical fluorophosphate glasses possessing positive anomalous partial dispersion and improved physico-chemical properties, and a process for their preparation" US patent 4857487
- ↑ Balda, R.; Fernández, J.; De Pablos, A. (April 1994). "Optical properties of Nd 3+ ions in fluorophosphate glasses". Le Journal de Physique IV 04 (C4): C4–509–C4-512. doi:10.1051/jp4:19944122. https://hal.archives-ouvertes.fr/jpa-00252573/file/ajp-jp4199404C4122.pdf.
- ↑ Lin, Fucheng; Mao, Sen; Meng, Zhicong; Zeng, Heping; Qiu, Jianqing; Yue, Yong; Guo, Ting (14 November 1994). "Fullerene doped glasses". Applied Physics Letters 65 (20): 2522–2524. doi:10.1063/1.112623. Bibcode: 1994ApPhL..65.2522L.
- ↑ "Durable Tungsten-Doped Tin-Fluorophosphate Glasses" WO patent 2008045249
 |  |
