Preparation of transparent cobalt doped glass ceramic and application as saturable absorber Q switch for 1.54 μm Er-glass laser

• Published in: Journal of non-crystalline solids Vol. 357; no. 11; pp. 2309 - 2311
• Main Authors: Yu, Chunlei, Feng, Suya, Chen, Li, He, Dongbing, Wang, Meng, Zhang, Liyan, Zhang, Junjie, Hu, Lili
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Oxford Elsevier B.V 01.06.2011; Elsevier
• Subjects: 1.54 μm Er-glass laser; Aluminum oxide; Cobalt doped; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Crystal structure; Crystallites; Exact sciences and technology; Fundamental areas of phenomenology (including applications); Glass; Glass ceramics; Laser materials; Magnesium; Nanostructure; Optical constants: refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity; Optical materials; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of bulk materials and thin films; Optics; Passive Q switch; Physics; Transmission electron microscopy; Transparent glass ceramic; Transparent glass ceramic; Cobalt doped; Passive Q switch; 1.54 μm Er-glass laser; Aluminium oxide; Crystalline phase; Coordination number; Magnesium oxide; Doping; Laser materials; XRD; Silicates; Absorption coefficients; Precipitation; Potassium additions; Transmission electron microscopy; Impurity site; Optical materials; Cobalt additions; Absorption spectra; Glass ceramics; Nanocrystal
• ISSN: 0022-3093; 1873-4812
• DOI: 10.1016/j.jnoncrysol.2010.11.058

Glass with composition of 51SiO 2–24.5Al 2O 3–23MgO–1.5K 2O doped with Co 2+ ions was prepared by conventional melting method. The glass sample was heated at 900 °C for 360 min under atmosphere, and the powder XRD measurement showed that crystalline phase successfully precipitated in the sample. As is compared with standard JCPDS card, the crystalline phase identified as a mixture of zirconium titanate (ZrTiO 4) and one of the compounds of magnesium aluminum oxide. The crystallite size was confirmed by transmission electron microscope (TEM) observation; it could be estimated as 30 nm in diameter from the TEM image. Based on the area ratio of crystalline phase and residual glass phase, the precipitated crystallite phase volume ratio can be estimated to be not higher than 30% in the Co 2+ doped glass ceramic sample. The absorption coefficient at 1.54 μm for transparent glass ceramic sample is clearly higher than that in base glass, which can be explained by the fact that Co 2+ ions entered into the precipitated nano-sized crystal phase and led to higher absorption coefficient at 1.54 μm for tetrahedral coordinated Co 2+ ion. Consequently, the Co 2+ doped transparent glass ceramic sample with thickness of 0.35 mm was used as a saturable absorber for 1.54 μm Er-glass laser oscillation, and Q switched pulses with pulse energy of 40 mJ, pulse width of 42 ns, and peak power of 0.95 mW were shown in the experiments.