Crystal growth and characterization OF La2CaB10O19 NdxLa2 xCaB10O19AND K2B4O11H8 for NLO and laser applications and theoretical analysis of nonlinear optical property of La2CaB10O19 crystal

Abstract

Fifty years ago, in 1960, Maiman created the first source of coherent radiation, namely a ruby laser generating in the red spectral region. Several years later a great family of lasers was in existence. The recent research activities focus mainly on materials exhibiting excellent second order nonlinear optical properties because of their potential applications in optoelectronic technologies, telecommunication, optical data storage, medical diagnostics, entertainment and optical signal processing. The present thesis consists of six chapters. A brief introduction and overview of non-linear optical borate single crystals employed in NLO applications is presented. The structure of the available borate materials, the research work reported in the literature for borate based single crystals and the applications of borate single crystals in the field of nonlinear optics are discussed in detail. A short introduction to the crystal growth techniques involved in the present investigations is also given. The theoretical analysis of nonlinear optical properties of LCB crystal was carried out. The synthesis and growth of lanthanum calcium borate single crystals was carried out. NdLCB (Nd with 1 and 5 mole %) polycrystalline materials was synthesized and confirmed by powder X-ray diffraction analysis. The growth of potassium tetraborate tetrahydrate (K2B4O11H8) single crystals was carried out using low temperature solution growth method by solvent evaporation at room temperature. UV studies reports that the crystal is more than 60% transparent in the UV and visible region. Etch pattern reveals that the grown crystals follows step growth pattern. The powder SHG test displays a green emission from K2B4O11H8 when Nd:YAG laser of 1064nm is passed and the crystal efficiently converts the IR pump wavelength to visible region. Hence this crystal can be useful in the frequency doubling applications and for other non-linear optical processes. The summary of the present investigations and the suggestions for future works are also discus