SCATTERING LOSS OF ANTIRESONANT REFLECTING OPTICAL WAVE-GUIDES

Scattering loss of two-dimensional ARROW-type waveguides, i.e., antiresonant reflecting optical waveguide (ARROW) and ARROW-B, is analyzed by the first-order perturbation theory. Calculated results are compared with those of conventional three-layer waveguides. Optimum design for the reduction of scattering loss of these ARROW-type waveguides is discussed. It was found that the scattering loss of ARROW-type waveguides is no larger than that of a conventional waveguide having a relative refractive-index difference DELTA of 2.5%, despite each interface of ARROW-type waveguides has a large DELTA, normally larger than 20%. The optimum design for the reduction of essential radiation loss of ARROW is also optimum for the reduction of scattering loss. As for ARROW-B, both scattering loss and radiation loss are small enough, even though some high-index material like polycrystalline glasses and semiconductors are adopted for the core.