JOSA B

Keto et al. Vol. 23, No. 8 / August 2006 / J. Opt. Soc. Am. B 1581

Nanoparticles of Er-doped glass produced
by laser ablation of microparticles

John W. Keto
Department of Physics C1600, Texas Materials Institute, and Center for Nano and Molecular Science
and Technology, The University of Texas at Austin, Austin, Texas 78712-1081

Michael F. Becker
Department of Electrical and Computer Engineering, Texas Materials Institute, and Center for Nano and Molecular
Science and Technology, The University of Texas at Austin, Austin, Texas 78712-1081

Desiderio Kovar
Department of Mechanical Engineering, Texas Materials Institute, and Center for Nano and Molecular Science
and Technology, The University of Texas at Austin, Austin, Texas 78712-1081

Gokul Malyavanatham
Texas Materials Institute, The University of Texas at Austin, Austin, Texas 78712-1081

Andreas Muller
Department of Physics, Texas Materials Institute, and Center for Nano and Molecular Science and Technology,
The University of Texas at Austin, Austin, Texas 78712-1081

Daniel T. O’Brien
Department of Electrical and Computer Engineering, The University of Texas at Austin, Austin, Texas 78712-1081

C. K. Shih
Department of Physics, Texas Materials Institute, and Center for Nano and Molecular Science and Technology,
The University of Texas at Austin, Austin, Texas 78712-1081

Jue Wang
Department of Mechanical Engineering and Texas Materials Institute, The University of Texas at Austin,
Austin, Texas 78712-1081

Received May 27, 2005; revised January 20, 2006; accepted January 24, 2006; posted March 24, 2006 (Doc. ID 62287)

We report the production of Er impurity-doped glass nanoparticles (NPs) by laser ablation of doped glass mi-
croparticles entrained in a flowing argon aerosol. The NP composition for this process is similar to the starting
feedstock material, so the manufacture of impurity-doped NP requires only an impurity-doped feedstock. In
experiments, NPs with a relatively large mean size of 20 nm were produced to purposely not confine the fluo-
rescence of the impurity; however, other valuable properties of the NPs such as low-temperature sintering
were retained. We measured the resulting changes in stoichiometry using energy dispersive spectroscopy in
both scanning electron microscopy and transmission electron microscopy. We measured the spectra from both
sparsely deposited regions consisting of individual NPs and clusters of NPs, and densely deposited regions
where the deposits formed nanostructured films. The spectra measured from sparse and dense deposits were
similar; for samples stored for six months in atmospheric conditions, the fluorescence measured from isolated
NPs was quenched, but not the fluorescence measured from the densely deposited nanostructured films. In
samples in which the fluorescence was measured within weeks of deposition, the fluorescence lifetimes were
found to be only 0.5 ms shorter than those of the starting microparticles, indicating that the nanostructure did
not significantly influence the defect or impurity quenching of the Er ions. © 2006 Optical Society of America
OCIS codes: 060.2410, 130.3130, 140.3500, 160.3380, 160.3220, 160.2540.