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Photorefractive self-focusing and defocusing as an optical limiter

Duree, Galen C., Jr. and Salamo, Gregory J. and Segev, Mordechai and Yariv, Amnon and Sharp, Edward J. and Neurgaonkar, Ratnakar R. (1994) Photorefractive self-focusing and defocusing as an optical limiter. In: Nonlinear Optical Materials for Switching and Limiting. Proceedings of SPIE. No.2229. Society of Photo-Optical Instrumentation Engineers (SPIE) , Bellingham, WA, pp. 192-199. ISBN 0-8194-1533-2.

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Focusing and defocusing of laser light has been observed for many years. Kerr type materials exhibit this effect but only for high intensities. We show experimental evidence that photorefractive materials can also produce dramatic focusing and defocusing. Whereas Kerr materials produce this effect for high intensities, photorefractive materials produce these effects independent of intensity indicating that this effect would be ideal for an optical limiter. We compare the characteristics of Kerr and photorefractive materials, discuss the physical models for both materials and present experimental evidence for photorefractive defocusing. Self-focusing and defocusing was observed for any incident polarization although the effect was more pronounced using extraordinary polarized light. In addition, self-focusing or defocusing could be observed depending on the direction of the applied electric field. When the applied field was in the same direction as the crystal spontaneous polarization, focusing was observed. When the applied field was opposite the material spontaneous polarization, the incident laser light was dramatically defocused.

Item Type:Book Section
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Additional Information:© 1994 The International Society for Optical Engineering. SPIE.
Series Name:Proceedings of SPIE
Issue or Number:2229
Record Number:CaltechAUTHORS:20161019-114538231
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Official Citation:Galen C. Duree, Jr. ; Gregory J. Salamo ; Mordechai Segev ; Amnon Yariv ; Edward J. Sharp ; Ratnakar R. Neurgaonkar; Photorefractive self-focusing and defocusing as an optical limiter. Proc. SPIE 2229, Nonlinear Optical Materials for Switching and Limiting, 192 (July 6, 1994); doi:10.1117/12.179585.
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:71274
Deposited By: Ruth Sustaita
Deposited On:19 Oct 2016 19:12
Last Modified:03 Oct 2019 16:05

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