Accession Number : ADA269305

Title :   Theory of Electromagnetic Waves Propagating in Nonlinear Anisotropic Optical Materials.

Descriptive Note : Final technical rept. 15 Mar 91-30 Jun 93,

Corporate Author : KENT STATE UNIV OH DEPT OF PHYSICS

Personal Author(s) : Moroi, David S.

Report Date : 30 JUN 1993

Pagination or Media Count : 60

Abstract : Method of multiple scales is used to calculate the electromagnetic fields for first and second harmonics, in first two orders of small parameter expansion, which satisfy the nonlinear coupled wave equations in a chi(2) medium. The results contain no secular terms nor ill-behaved terms. The fields obtained in lowest order calculations are the same as those in slowly varying amplitude approximation. The secular terms and ill-behaved terms resulted in the previous calculations are carefully removed in consistent with this method. We have shown that the first order correction to the electromagnetic field in each harmonic in slowly varying amplitude approximation is down by a factor of 10(exp -5) compared with the leading term. In other words, slowly varying amplitude approximation itself is proven to be a very good approximation. We have estimated the angular deviation of light propagation direction from a straight line in a chi(2) medium which is roughly in a range of 0.2 - 0.6 for an incident laser of intensity 6kW/sq cm. We have obtained the exact coupled differential equations for the amplitudes of the lth confined TE and TM modes for both first and second harmonics in a nonlinear slab waveguide. They become slightly simplified in slowly varying amplitude approximation but still too complicated to be tractable. For a special case of a nonlinear slab waveguide made of material with bar-42m crystalline symmetry, these equations are further simplified. For the case of perfect phase matching or very small phase mismatch and of other specific conditions being met, the equations are reduced to the well-known coupled differential equations which have the solutions given by Jacobian elliptic functions.

Descriptors :   *AMPLITUDE, *DIFFERENTIAL EQUATIONS, *ELECTROMAGNETIC WAVE PROPAGATION, *OPTICAL MATERIALS, *ANISOTROPY, *GRADIENTS, ATOMS, CORRECTIONS, DENSITY, ELECTROMAGNETIC FIELDS, ESTIMATES, NONLINEAR OPTICS, APPROXIMATION(MATHEMATICS), EXPANSION, EXTERNAL, FUNCTIONS, HARMONICS, INTENSITY, LASERS, LIGHT, MATCHING, NEUTRAL, PARAMETERS, PHASE, POLARIZATION, SYMMETRY, TRACTABLE, VARIATIONS, WAVE EQUATIONS, WAVEGUIDES.

Subject Categories : Optics
      Fluid Mechanics
      Radiofrequency Wave Propagation
      Theoretical Mathematics

Distribution Statement : APPROVED FOR PUBLIC RELEASE