Structural and fluorescence properties of thin films fabricated by pulsed laser deposition technique from Nd:KGW single crystal

• Published in: Optical materials Vol. 28; no. 4; pp. 360 - 369
• Main Authors: Lancok, J., Garapon, C., Vorlíček, V., Jelinek, M., Čerňanský, M.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.03.2006; Elsevier Science
• Subjects: Exact sciences and technology; Fundamental areas of phenomenology (including applications); Gas lasers including excimer and metal-vapor lasers; Laser materials; Lasers; Micro-Raman spectroscopy; Nd:KGW films; Optical materials; Optics; Physics; 42.70.−a; 81.15.−Fg; 42.70.−Hj; 78.55.−Hx; Nd:KGW films; Micro-Raman spectroscopy; Fluorescence spectrum; Amorphous material; Gadolinium tungstates; Fluorescence; Polycrystals; 42.70.-a; Laser materials; XRD; Krypton fluoride lasers; Thin films; Neodymium additions; 81.15.-Fg; Excitation spectrum; Excimer lasers; Gas lasers; Quaternary compounds; Scanning electron microscopy; Doped materials; Pulsed laser deposition; 78.55.-Hx Micro-Raman spectroscopy; Experimental study; Luminescence decay; Lifetime; Monocrystals; Potassium tungstates; Optical materials; Laser ablation technique; Potassium; 42.70.-Hj
• ISSN: 0925-3467; 1873-1252
• DOI: 10.1016/j.optmat.2005.01.023

Textured and amorphous thin films were deposited by KrF laser ablation of neodymium doped potassium gadolinium tungstate, KGd1−xNdx(WO4)2 (Nd:KGW) single crystal in oxygen ambient atmosphere on MgO, YAP (YAlO3) and YAG (Y3Al5O12) substrates at temperatures up to 800°C. The influence of substrate nature and substrate temperature (Ts) on films crystallinity and morphology were studied by conventional X-ray diffraction (XRD), micro-Raman spectroscopy (μRS) and scanning electron microscopy (SEM). Related emission and excitation spectra and fluorescence decay were examined. The strongly textured polycrystalline Nd:KGW films with fluorescence spectra very close to those of bulk single crystal were deposited only on YAG substrate at higher Ts, whereas the smoother films were obtained at Ts=400°C on all types of substrates. Fluorescence properties of the films corresponding to the transitions from the 4F3/2 doublet to the 4I9/2, 4I11/2 and 4I13/2 multiplets, at about 890nm, 1.06μm and 1.3μm, bring a new information about the structure of the film at the scale of the Nd3+ ions environment, which could not be detected by XRD method. The fluorescence decay was almost exponential, with a lifetime of about 110μs for polycrystalline KGW films.