Accession Number : ADP008085

Title :   A New Transfer Matrix Approach to Optical Grating Structures,

Corporate Author : WATERLOO UNIV (ONTARIO)

Personal Author(s) : Huang, W. P. ; Hong, J.

Report Date : APR 1992

Pagination or Media Count : 2

Abstract : Optical grating structures are basic elements in filters, DFB/DBR lasers. Coupled-mode theory is often used in the analysis of these devices. The mode patterns in the coupled-mode analysis do not vary along waveguide axis. The periodic perturbations therefore only change the amplitudes of the ideal modes. This approximation is, however, valid only if the grating perturbation is weak. Otherwise, the ideal mode approximation will become questionable. The problem is more serious for the TM modes because the ideal modes do not satisfy the boundary conditions at the interface. The coupling coefficients evaluated based on the ideal-modes are not correct even for small grating height. Moreover, as the grating perturbations increases, the possible radiation loss due to the scattering at the surface grating will also become inevitable. The complicated expressions of the radiation modes is required in the coupled-mode analysis to assess the radiation loss.

Descriptors :   *INTERFACES, *OPTICAL WAVEGUIDES, AMPLITUDE, BOUNDARIES, COEFFICIENTS, FILTERS, HEIGHT, LASERS, PATTERNS, PERTURBATIONS, RADIATION, STRUCTURES, SURFACES, THEORY, CANADA, GRATINGS(SPECTRA), LIGHT SCATTERING, WAVEGUIDE COUPLERS.

Subject Categories : Optics

Distribution Statement : APPROVED FOR PUBLIC RELEASE