guided waves, integrated optics, optical devices, photonics
We previously proposed the hybrid integration of photonic crystals (PhCs) and conventional index-guided waveguides (CWGs) as a potentially attractive method of realizing compact waveguide elements for large-scale planar lightwave circuits (PLCs). We now examine 90-deg bends and beamsplitters in PhC/CWG structures in which the waveguide core has a high refractive index (3.25) and yet a low refractive index contrast (1.54%) with the clad material. A PhC structure composed of a triangular or square array of air holes is placed at the intersection of input and output waveguides to obtain high efficiency 90-deg bends. We find that diffraction from the boundary of the PhC region with CWG limits the optical efficiency of the bend. To overcome this we use a rigorous design tool based on a microgenetic algorithm (μGA) and a finite difference time domain (FDTD) method to optimize the boundary layer to suppress the unwanted diffraction. We find that this approach yields improvements in the bend efficiency at a wavelength of 1.55 μm from 56.2 to 92.5% (for a triangular PhC structure, TE polarization) and from 72.0 to 97.4% (square PhC structure, TM polarization). © 2004 Society of Photo-Optical Instrumentation Engineers.
Original Publication Citation
S. Kim, G. P. Nordin, J. Jiang, and J. Cai, "Micro-genetic algorithm design of hybrid conventional waveguide and photonic crystal structures," Opt. Eng., 43(9), pp. 2143-2149 (24)
BYU ScholarsArchive Citation
Cai, J.; Kim, S.; Nordin, Gregory P.; and Jiang, J., "Micro-genetic algorithm design of hybrid conventional waveguide and photonic crystal structures" (2003). All Faculty Publications. 1024.
SPIE -- Society of Photo-Optical Instrumentation Engineers
Ira A. Fulton College of Engineering and Technology
Electrical and Computer Engineering
© 2004 Society of Photo-Optical Instrumentation Engineers. This paper was published in Optical Engineering and is made available as an electronic reprint with permission of SPIE. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper are prohibited
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