Comparative growth study of garnet crystal films fabricated by pulsed laser deposition

• Published in: Journal of crystal growth Vol. 308; no. 2; pp. 382 - 391
• Main Authors: May-Smith, T.C., Eason, R.W.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.10.2007; Elsevier
• Subjects: A1. Film; A3. Pulsed laser deposition; B1. Garnet crystal; B3. Optical; B3. Waveguide; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Defects and impurities: doping, implantation, distribution, concentration, etc; Exact sciences and technology; Laser deposition; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Physics; Structure and morphology; thickness; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Theory and models of film growth; Thin film structure and morphology; B3. Waveguide; B1. Garnet crystal; 77.55.+f; 42.82.Et; 42.70.Hj; A1. Film; 81.15.Fg; 81.15.−z; B3. Optical; A3. Pulsed laser deposition; Epitaxy; XRD; Thin films; Multilayers; Aluminium oxides; Crystal structure; Epitaxial layers; Phase composition; Multilayer; Pulsed laser deposition; Operating conditions; Film growth; Gadolinium oxides; Ordered crystals; 81.15.Fg; 81.15.-z; 42.70.Hj; 42.82.Et; 77.55.+f; Gallium oxides; Monocrystals; Garnets; Waveguide lasers; Growth mechanism; Al. Film; A3. Pulsed laser deposition; Bl. Garnet crystal; B3. Optical; B3. Waveguide; Laser ablation technique; Comparative study; YAG; Yttrium oxides; Energy-dispersive X-ray analysis
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/j.jcrysgro.2007.08.014

We report here a comparative film growth study of several different garnet crystal compositions intended for optical waveguide applications. Films of Nd,Cr:Gd 3Sc 2Ga 3O 12; Cr:Gd 3Sc 2Al 3O 12; Nd,Cr:Y 3Sc 2Al 3O 12; Nd:Gd 3Ga 5O 12; Y 3Ga 5O 12; Y 3Al 5O 12 (YAG) and Yb 3Al 5O 12 (YbAG) have all been grown by the technique of pulsed laser deposition (PLD). X-ray diffraction results from the films are in line with the occurrence of single crystal epitaxial growth on the YAG (1 0 0)-oriented substrates and reveal that they have well ordered crystal structures, some being of a quality approaching that of the substrates. Energy dispersive X-ray analysis shows that the film compositions can be slightly deficient compared to the targets and a relative ‘deposition volatility’ of different elements, which follows a trend related to elemental boiling points can be assigned, suggesting that the compositional deficiencies may occur as a result of rejection from the growing film. Spectroscopic measurements of YbAG film show that the strength of absorption for different Yb 3+ transitions is not the same as for bulk crystal, indicating the possibility for tuning the absorption properties of films to a desired pump wavelength. This growth study has shown that several different garnet crystals can be grown under the same deposition conditions and indicates the potential of PLD to be used as a fabrication technique for advanced multilayer planar waveguide laser structures.