Laser IInduced Liinear and Nonlliinear Optiicall Studiies on Certaiin Metall Halliides and Tartrate Crystalls ffor Photoniic Applliicatiions

Abstract

Nonlinear optics is a broad field of research and technology that newlineencompasses subject matter in the field of Physics, Chemistry, and Engineering. newlineIt is the branch of Optics that describes the behavior of light in nonlinear media, newlinethat is, media in which the dielectric polarization P responds nonlinearly to the newlineelectric field E of the light. This nonlinearity is typically only observed at very newlinehigh light intensities. This area has applications in all optical and electro optical newlinedevices used for communication, optical storage and optical computing. Many newlinenonlinear optical effects have proved to be versatile probes for understanding newlinebasic and applied problems. Nonlinear optical devices use nonlinear dependence newlineof refractive index or absorption coefficient on the applied field. These nonlinear newlineoptical devices are passive devices and are referred to as intelligent or smart newlinematerials owing to the fact that the sensing, processing and activating functions newlinerequired for optical processes are inherent to them which are otherwise separate newlinein dynamic devices.The large interest in nonlinear optical crystalline materials has been newlinemotivated by their potential use in the fabrication of all-optical photonic devices. newlineTransparent crystalline materials can exhibit different kinds of newlineoptical nonlinearities which are associated with a nonlinear polarization. The newlinechoice of the most suitable crystal material for a given application is often far newlinefrom trivial; it should involve the consideration of many aspects. A high newlinenonlinearity for frequency conversion of ultra-short pulses does not help if the newlineinteraction length is strongly limited by a large group velocity mismatch and the newlinelow damage threshold limits the applicable optical intensities. Also, it can be newlinehighly desirable to use a crystal material which can be critically phasematched newlineat room temperature.Among the different types of nonlinear crystals, metal halides and newlinetartrates have attracted due to their importance in photonics. Metal halides like newlinelead halides have drawn attention because they exhibit interesting features from newlinethe stand point of the electron-lattice interaction .These materials are important newlinefor their luminescent properties. Tartrate single crystals show many interesting newlinephysical properties such as ferroelectric, piezoelectric, dielectric and optical newlinecharacteristics. They are used for nonlinear optical devices based on their optical newlinetransmission characteristics. Among the several tartrate compounds, Strontium newlinetartrate, Calcium tartrate and Cadmium tartrate have received greater attention newlineon account of their ferroelectric, nonlinear optical and spectral characteristics. newlineThe present thesis reports the linear and nonlinear aspects of these crystals and newlinetheir potential applications in the field of photonics. newline