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(a) Top view of a rectangular waveguide with sidewall roughness. (b) Angled view of a randomly deformed waveguide. The 1-D deformation, g(z), affects only the width of the waveguide, while its thickness d remains constant. Also shows the E field of the even pth mode in y and E field of the even qth mode in y, on the waveguide left boundary.
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This paper calculates and displays accurate radiation modes for rectangular, multimode. dielectric, channel waveguides, for the first time, and introduces the new semi-analytical calculation method used to find them, the Radiation mode Fourier Decomposition Method (RFDM), which is an extension of the Fourier Decomposition method (FDM) for finding b...
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... presented. We refer the reader to see [1]- [8] for a more detailed description of the coupled power theory for slab waveguides and optical fibers. Fig. 8 shows a schematic of a waveguide that will be analyzed. A piece of an imperfect waveguide of length , where can be infinite, is attached to a perfect waveguide at . The refractive index of the perfect waveguide is a function of the transverse coordinates ...
Context 2
... two bound modes is proportional to the product of their electric field values taken on the waveguide boundary and then integrated in the direction of its thickness. However, if the two modes have different symmetries in the direction of the waveguide thickness, for example the th mode has even symmetry in and the th mode has odd symmetry in [see Fig. 8(b)], then their product is an odd function whose inte- gral along a symmetrical interval about is exactly zero. According to the modal symmetries defined in Section II, the modes with even-even and odd-even symmetry only couple with the modes of the same symmetry group (even-even and odd-even). Similarly, modes with odd-odd and even-odd ...
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Citations
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In-plane bend loss represents the greatest commercial inhibitor to
deploying multimode optical waveguides on densely populated
electro-optical printed circuit boards (OPCB) as the minimum bend radii
currently possible are too large to be practical in common designs. We
present a concept and fabrication method for creating novel polymer
optical waveguide structures with reduced bend losses to enable higher
density routing on an OPCB. These nested core waveguide structures
comprise a core surrounded by a thin shell of cladding, which allows for
two-fold modal containment by first a conventional low refractive index
contrast (LIC) boundary followed by a secondary high refractive index
contrast (HIC) boundary. The purpose of this is to reduce the in-plane
bend losses incurred on tightly routed optical channels, while not
incurring prohibitive dispersion, sidewall scattering and optical
crosstalk penalties. We have designed and fabricated nested core
multimode polymer waveguides, evaluated their performance in comparison
to conventional step-index waveguides and simulated these structures
using the beam propagation method. Preliminary results are presented of
our measurements and simulations.
