Investigation of emission properties of Tm3+:Y2O3 transparent ceramic

Abstract

A transparent and emitting ceramic of Y2O3 doped with 6% Tm 3+ ions is fabricated by vacuum sintering with ZrO2. Absorption, photoluminescence (PL), and PL excitation (PLE) spectra are investigated in a spectral range of 200 to 2 100 nm at various temperatures between 296 and 12 K. Intense emission band appears at 450 to 465 nm in the visible range. Near-infrared emission bands are observed at 1 200 to 1 300 nm and 1 400 to 1 550 nm, with intense peaks at 1 270, 1 450, and 1 523 nm. The luminescence mechanisms and potential applications of the emissions are discussed with the help of Judd-Ofelt theory and PLE spectra.OCIS 12 . However, the high melting point of 2 430• C and phase transformation at approximately 2 280• C of Y 2 O 3 make it considerably difficult to grow single Y 2 O 3 crystals by conventional methods. On the contrary, transparent ceramics are much easier to produce than single crystals because of much lower processing temperatures.Since the first demonstration of Nd:YAG ceramic laser in 1995 by Ikesue [3] , transparent ceramic materials have received a wide attention [4−7] . Transparent ceramics have optical properties comparable to single crystal, but with better mechanical properties. Additionally, fabrication of materials with big size is much easier for ceramics than for single crystals. These advantages make transparent ceramics attractive for laser media, fluorescent materials, and window materials.In [8−10] , the measurements were made at room temperature, not at low temperatures. We report the photoluminescence (PL) and PL excitation (PLE) spectra of Tm 3+ -doped Y 2 O 3 ceramic at temperatures from 12 to 295 K. The luminescence mechanisms and the potential of the laser application are also discussed.High-purity commercial powders of Y 2 O 3 (99.99%), Tm 2 O 3 (99.99%), and ZrO 2 (99.99%) were used as starting materials. The powders were weighed according to the stoichiometry of (Zr 0.03 Tm 0.06 Y 0.91 ) 2 O 3 , then ballmilled in alcohol for 20 h. The obtained slurries were dried and then ground with a pestle. The mixed powders were sieved through a 200 mesh screen. Next, the powders were dry-pressed in a stainless steel mold into discs 15 mm in diameter and 3 mm in height under low pressure. The discs were cold-isostatic-pressed under 250 MPa. The pressed discs were calcined at 600 to 1 000 • C for 2 h. Eventually, transparent ceramics were obtained after vacuum sintering at 1 800• C for 20 h with a vacuum degree of 1×10 −3 Pa. The polished discs were etched in H 3 PO 4 at 80• C for 3 min for the observation of the microstructures. The synthesized ceramics were polished for optical measurements.The optical transmittances were obtained by a UV/VIS/NIR spectrophotometer (V-900, JASCO, Japan). The PL spectra in the temperature range of 12 to 295 K and PLE spectra at 12 and 295 K were measured with a spectrophotometer (Fluorolog-3, Spex, USA). Infrared PL spectra were measured in a spectral range of 800 to 1 600 nm using a liquid-nitrogen-cooled InGaAs photodiode (DSSX-IGA010I, Jobin-Yvo...

2.1 μm Ho:LuAG ceramic laser intracavity pumped by a diode-pumped Tm:YAG laser

“…As a novel laser medium, transparent ceramics have several advantages over single crystals in many aspects, such as the capability for a rapid and large volume fabrication, and flexibility in doping concentration [13][14][15] . LuAG is an isostructure of YAG, and its mechanical properties are similar to YAG.…”