Accession Number : ADP006770

Title :   Application of Beam Fanning in a Photorefractive BaTiO sub 3 Crystal: Measurement of Light Scattering at Zero Degrees by a Single Glass Fiber,

Corporate Author : TEXAS A AND M UNIV COLLEGE STATION DEPT OF PHYSICS

Personal Author(s) : Padmabandu, G. G. ; Oh, Choonghoon ; Fry, Edward S.

Report Date : 22 MAY 1992

Pagination or Media Count : 3

Abstract : The photorefractive effect in Barium titanates has been the subject of extensive research in recent years. Because of very large electro-optic coefficients. BaTiO3 has become a unique candidate for a variety of nonlinear optical devices which operate at very low light intensities. Most of these devices use energy transfer between coherent optical beams that interfere inside the crystal while some devices use the extinction of a single beam through beam fanning. In this letter, we will discuss the use of a BaTiO3 beam fanning limiter to make quantitative measurements. and will present the first measurement of zero degree scattering from micron sized glass fibers. A coherent light beam that propagates through a BaTiO3 crystal fans out in a direction determined by the c axis of the crystal. With proper choice of the angle of incidence more than 99% of the input intensity can be removed from the incident beam using a 5 mm crystal. Beam fanning occurs due to a refractive index gradient that is formed across the the illuminated area and which causes the beam to be deflected. The index gradient is produced by optically induced charge migration, which in turn induces an anisotropic electric field inside the crystal.

Descriptors :   *NONLINEAR OPTICS, *LIGHT SCATTERING, ANGLE OF INCIDENCE, ANGLES, COEFFICIENTS, CRYSTALS, ELECTRIC FIELDS, ENERGY, ENERGY TRANSFER, EXTINCTION, GLASS, GRADIENTS, INTENSITY, LIGHT, LIMITERS, MEASUREMENT, MIGRATION, OPTICS, REFRACTIVE INDEX, SCATTERING, REFRACTION, BARIUM TITANATES, ELECTROOPTICS, BEAMS(RADIATION), FIBER OPTICS, COHERENT OPTICAL RADIATION, SYMPOSIA.

Subject Categories : Optics

Distribution Statement : APPROVED FOR PUBLIC RELEASE