Optical waveguides, nonlinear

Second-order nonlinear optical waveguide using noncentro-symmetric LB film of pyrazine derivative... 

T. Fujisawa, and M. Koshiba, Full-vector finite-element beam propagation method for three-dimensional nonlinear optical waveguides. Journal of Lightwave Technology 19, 1876-1884 (2002). 

Cahill, P.A. Nonlinear optical waveguides containing a transition metal-based dye molecule. Mater. Res. Soc. Symp. Proc. 109, 319-322 (1988)... 

Serious attempts to use LB films in commercial appHcations include the use of lead stearate as a diffraction grating for soft x-rays (64). Detailed discussion on appHcations of LB films are available (4,65). From the materials point of view, the abiHty to build noncentro symmetric films having a precise control on film thickness, suggests that one of the first appHcations of LB films may be in the area of second-order nonlinear optics. Whereas a waveguide based on LB films of fatty acid salts was reported in 1977, a waveguide based on polymeric LB films has not yet been commercialized. 

For the practical application to nonlinear optics, further, noncentrosymmetric LB films are required to possess not only large nonlinear optical response but excellent optical quality and thickness appropriate to optical devices. In this study, a family of pyrazine derivatives was found to be an LB film-forming material applicable to waveguide devices. The optical nonlinearity in the pyrazine LB films and the application of the pyrazine LB films to a frequency-doubling waveguide device is demonstrated in the latter part. 

PROPAGATION OF OPTICAL PULSES THROUGH NONLINEAR PLANAR WAVEGUIDES WITH JUNCTIONS... 

Key words Kerr nonlinearity, planar waveguides, optical pulses, numerical modeling, nonlinear modes, waveguide junctions. 

In this section, a problem of nonlinear waveguide excitation by stationary light beam has been investigated. In the analysis, an approach traditional for nonlinear optics and based on solution to nonlinear paraxial wave equation has been used. The range of light beam powers that induce nonlinear variation of refractive index comparable with linear contrast of the step-index waveguide has been considered. 

Theoretical approach based on solution to the (2D-I-T) parabolic wave equation traditional for methods of nonlinear optics has been used. This approach is feasible if linear refractive index contrast in the waveguide is small and comparable with the nonlinear part of the refractive index. Then the back-reflected field can be ignored. 

In a QPM nonlinear optical process, the waveguide is segmented into regions with alternating anti-parallel ferroelectric domains. For SHG, the... 

J. Rams, F. Agullo-Rueda, J.M. Cabrera, Structure of high index proton exchanged LiNb03 waveguides with undegraded nonlinear optical coefficients, Appl. Phys. Lett. 71. 3356-3358 (1997). 

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