A new microwave resonant technique for studying rare earth photoionization thresholds in dielectric crystals under laser irradiation

• Published in: Optical materials Vol. 24; no. 1; pp. 137 - 141
• Main Authors: Joubert, M.-F., Kazanskii, S.A., Guyot, Y., Gâcon, J.-C., Rivoire, J.-Y., Pédrini, C.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 01-10-2003; Elsevier Science; Elsevier
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Electron and ion emission by liquids and solids; impact phenomena; Exact sciences and technology; Field emission, ionization, evaporation, and desorption; Physics; Conduction bands; Energy levels; Photoionization; Microwave radiation; Dielectric materials; Lutetium silicates; Doped materials; Rare earth additions; Laser irradiation; Absorption spectra; Calcium fluorides
• ISSN: 0925-3467; 1873-1252
• DOI: 10.1016/S0925-3467(03)00117-4

A new technique is presented for measuring the location of the rare earth energy levels with respect to the host conduction band in rare earth doped insulators. This technique is based on the detection of microwave absorption by the rare earth doped crystal inserted in a resonant microwave cavity and irradiated by photons of sufficient energy to induce the rare earth photoionization. The results obtained with CaF
2:Sm
2+ and Lu
2(SiO
4)O:Ce
3+ indicate photoionization thresholds at 380 nm (3.3 eV) and 400 nm (3.1 eV), respectively.