Dissertation > Excellent graduate degree dissertation topics show

Research on Growth and Properties of BaWO4 Crystal

Author: LiXiao
Tutor: ZuoJingCun
School: Beijing University of Technology
Course: Materials Science
Keywords: laser crystal BaWO4 stimulated Raman scattering Yb3+ ion spectrum
CLC: TB383.4
Type: Master's thesis
Year: 2006
Downloads: 86
Quote: 0
Read: Download Dissertation


Barium tungstate crystal was recently developed as a new promising nonlinear material for crystalline nano- and picosecond Raman lasers. Doping this crystal with Yb3+ and Er3+ ions could allow it to be used as a laser active element and a nonlinear Raman medium simultaneously. In this report the single crystals of BaWO4, Yb3+, Er3+:BaWO4, and Yb3+:BaWO4 with different concentrations of K+ -codoped ions were successfully grown along c-axis direction by using the Czochralski method.Research on the process of growth and growth pattern of crystals shows that constitutional super-cooling, dislocation are the main reasons influencing the obtainment of the high qualitative BaWO4 crystals grown in the direction of <110>. The cracking of crystals due to large anisotropy in linear thermal expansion for different crystallographic directions is also an important reason, especially for the growth of crystals doped with rare earth ions. Choice of appropriate growth processing parameters could avoid the effect due to the factors mentioned above.The measurement and calculation of the sample density and X-ray powder diffraction of Yb3+:BaWO4 crystals were used to check the influence of K+ -codoped ions on the lattice structure. Influence of K+ ions on absorption and fluorescence spectra of Yb3+:BaWO4 crystals were analyzed. All these shows that a certain quantity of K+ ions doped in Yb3+:BaWO4 crystals will help to increase the quantity of Yb3+ doped ions, and improve the properties of absorption.Fluorescence spectrum of Er3+ ions in Yb3+, Er3+:BaWO4 crystals was obtained using 334nm laser as the pump light. Through analyzing and calculating absorption and fluorescence spectra, level parameters of Er3+ ions in Yb3+, Er3+:BaWO4 were obtained partly. The analysis of transition channel of Er3+ ions shows the possibility of formation of four-level structure according to the 4G9/2→4I9/2 transition at 670nm excited by short-wave laser.Spontaneous Raman spectra of BaWO4 crystal excited by 488nm argon ions laserat room temperature were obtained, and the linewidth of the Raman lines were

Related Dissertations

  1. Optical Spectrum Diagnose of Stationary Plasma Thruster Channel Wall Sputtering Erosion,V433.9
  2. Superresolution of Hyperspectral Images Based on Spatial-Spectral Information Coordination,TN911.73
  3. Research on the Doppler Wireless Location Techniques Based on DSSS,TN914.42
  4. Packet Loss Recovering Technology for Speech Transmission over Network,TN912.3
  5. The Simulation and Analysis of Spectrum Sensing Based on Higher Order Cumulants,TN911.23
  6. The Research and Implementation of Protein Classification Algorithm on the Basic of String Kernel,TP301.6
  7. Expression and Purification of Influenza a Virus M2 Protein and Detection of Its Antigenicity,R392
  8. Oxygen Delignification and Bleaching with Chlorine Dioxide of Reed Kraft Pulp,TS745
  9. The Analysis of the Disease Constituent Ratio in 1130 Inpatients of the Department of Nephrology,R692
  10. Clinical Research of Bacteria Spectrum and the Change of Bacterial Drug Resistance About Pediatric Diseases During Six Years,R446.5
  11. Electron Acceleration by Intense Laser in Vacuum,TN241
  12. Theoretical Analysis of the Circular Dichroism Spectra of Transition Metal Schiff-Base Complexes,O641.4
  13. Rapid Genotyping of ESBL Gene in Escherichia Coli and Drug Resistance Prediction,R446.5
  14. Ten Year’s Data Analysis on the Patients Who Died in Cardiology Department of Our Hospital,R54
  15. Research on Spectrum Sensing in Cognitive Radio Systems,TN925
  16. Research on Spectrum Allocation Technology of Cognitive Radio,TN925
  17. Research Oncognitive Radio Cooperate Spectrum Sensing,TN925
  18. Research on Spectrum Sensing Technology Base on Cognitive Radio,TN925
  19. Research on Resource Allocation Based on Cooperative Technology in Cognitive Radio Networks,TN925
  20. The ~1HMRS and DWI Study of AIDS with Toxoplasmic Encephalitis,R512.91
  21. Study on Disease Spectrum of Rural Residents in Yuanling County,R197.1

CLC: > Industrial Technology > General industrial technology > Materials science and engineering > Special structural materials
© 2012 www.DissertationTopic.Net  Mobile