Hofmeister, Rudolf (1993) Growth and applications of photorefractive potassium lithium tantalate niobate (KLTN). Dissertation (Ph.D.), California Institute of Technology. http://resolver.caltech.edu/CaltechETD:etd-08272007-134313
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This thesis describes the growth of photorefractive potassium lithium tantalate niobate (KLTN) single crystal material and characterization of its physical and photorefractive properties. The band transport model is used to discuss the conventional photorefractive effect. The coupled mode formalism is introduced to determine the interaction of interfering light beams in a photorefractive material. Solutions for intensity coupling and phase coupling between two beams, as well as diffraction off a dynamic index grating, are presented for both the copropagating and counterpropagating experimental geometries. These solutions are obtained for arbitrary photorefractive phase, [...]. The linear- and quadratic electro-optic effects are discussed. The influence of electric field application on the electro-optic tensor is described.
The top seeded solution growth method is reviewed. The design and construction of a crystal growth system is described. The growth procedures of KLTN are enumerated for several compositions and dopant types. Phase diagrams of the KLTN system are determined. Structural properties of the grown crystals are presented. Certain material characteristics of KLTN are discussed. These include the phase transition temperatures, dielectric properties, and the optical absorption properties.
Electric field control of the photorefractive effect, beam coupling and diffraction, is demonstrated for paraelectric KLTN. A theory is developed to describe the diffraction of beams off photorefractive index gratings in paraelectric KLTN. The solutions of the coupled mode equations are used to develop methods of determining the photorefractive phase [...] in a photorefractive material. These methods are experimentally demonstrated for several types of photorefractive material. In addition, they are used to corroborate a theory describing the magnitude and phase of the net holographic grating in paraelectric KLTN under applied electric field.
A new effect, the Zero External Field Photorefractive (ZEFPR) effect is studied, as well as the application of its unique zero phase ([...] = 0) photorefractive gratings. The ZEFPR effect is forbidden by the conventional photorefractive theory; its origin is shown to be due to the creation of strain gratings under spatially periodic illumination. A theory of coordination of microscopic strains by a macroscopic (growth induced) strain is presented. The ZEFPR gratings are shown to possess identically zero phase when no external electric field is applied. This property is employed in the implementation of various new linear phase-to-intensity transduction devices. In particular, an all-optical phase modulation/vibration sensor (microphone) is described. This device is expected to have numerous applications in environments where electric fields cannot be permitted. The possible implementation of ZEFPR gratings in high speed self aligning interferometric data links is discussed, as well as implementation of a novel self aligning holographic image subtraction device.
The final chapter is devoted to the solution of beam coupling and diffraction off of a "fixed" photorefractively written holographic plane grating. The solutions and mathematical tools developed in this chapter are used extensively throughout the thesis: in chapters two and five to describe diffraction off a photorefractive grating, in chapters seven and eight to solve for the beam coupling off a grating when one beam is phase modulated, and in chapter nine to study the spectral response of fixed holographic interference filters. The techniques are presented with sufficient generality to allow application to numerous other problems, not limited to the ones described here.
|Item Type:||Thesis (Dissertation (Ph.D.))|
|Degree Grantor:||California Institute of Technology|
|Division:||Engineering and Applied Science|
|Major Option:||Applied Physics|
|Thesis Availability:||Restricted to Caltech community only|
|Defense Date:||12 May 1993|
|Default Usage Policy:||No commercial reproduction, distribution, display or performance rights in this work are provided.|
|Deposited By:||Imported from ETD-db|
|Deposited On:||06 Sep 2007|
|Last Modified:||26 Dec 2012 02:58|
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