Microwave simulation of optoelectronic bending loss in presence of dielectric discontinuity

Abstract

A theory is developed and compared with experimental results. The theory enables calculation of the curvature loss from a partially buried dielectric waveguide in the presence of a strong air/dielectric planar interface. Comparison is made between numerical predictions based on this theory and experimental results for a smooth waveguide of rectangular cross-section. Agreement is found to be striking, even when the position of the caustic should, in theory, render the waveguide lossy.

Ultrasmall waveguide bends: the corner mirrors of the future?

“…They have applied these results to the rib waveguide and predicted that the curvature loss would drop dramatically when the outer slab waveguide of the layered structure is cut off. This theoretical prediction has been confirmed by microwave simulation [15]. In our work, the outer slab of the curved waveguides is indeed cut off, and the qualitative aspects of this theory are shown to be strongly supported by our results.…”

Semivectorial polarised H̃ field solutions for dielectric waveguides with arbitrary index profiles

“…A semi-vectorial polarised £ field method has recently been used, with considerable success, to determine propagation modes of semiconductor rib, channel, embedded, and buried waveguides [1][2][3][4][5][6]. The finite difference schemes for quasi-TE and quasi-TM modes automatically take full account of the discontinuities in the normal electric field components across any arbitrary distribution of internal dielectric interfaces [1].…”

“…It is now supposed that (a) field value H r s in cell P 'sees' a spurious field value H* + l s incellK (6) field value H r+l s in cell R 'sees' a spurious field value H* s in cell P. …”