A New Transfer Matrix Approach to Optical Grating Structures,
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.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 1992
- Accession Number
- ADP008085
Entities
People
- Jonathan Hong
- W. P. Huang
Organizations
- University of Waterloo