9:30 AM - 11:30 AM
[21a-P8-1] Rare-earth dependence of ultraviolet absorption edge of rare-earth and phosphorus codoped silica glasses
Keywords:silica glass,rare-earth orthophosphate nanocrystal,UV absorption edge
Monolithic silica glasses containing nanocrystals of rare-earth (RE) orthophosphates (REPO4, where RE = Y, La-Lu except Pm) were prepared by a cosolvent-free sol-gel method. Despite the large refractive index mismatch between the REPO4 nanocrystals and the host silica glass, these glasses are highly transparent in the deep-ultraviolet (deep-UV, DUV) spectral region (~<300 nm) because Rayleigh scattering is suppressed by the small crystal size (~5-10 nm) and narrow size distribution. The UV absorption edge originates from the electronic transitions in PO4 units for glasses containing Y3+, La3+, Gd3+, and Lu3+ ions and from the 4f-5d or charge transfer transition for glasses containing other RE3+ ions with partially filled 4f shells.