Abstract

Time domain propagation algorithms have the general advantages of full vectorial formulation, calculation of transmission characteristica in one step, and the automatic and accurate inclusion of reflections. The latter properties are particular important for the analysis of grating devices. Gratings are very important elements for key components for WDM lightwave transmission systems and WD photonic switching systems in direct detection scheme. Especially, semiconductor wavelength tunable optical filters for laser diodes, semiconductor optical switches and photodetectors are some examples for the application of grating filters. A time domain analysis is useful e.g. in connection with waveguide reflections, since beam propagation techniques, which have the ability to treat reflected waves, are very time consuming and to our knowledge combined with errors, such as lack of energy conservation in lossless waveguides. Within the time domain the algorithm described in [1] has been extensively used in microwave techniques and was introduced in integrated optics by [2]. Though a calculation with all relevant electric and magnetic field components is very time consuming. The other way to form a propagation algorithm in the time domain is to apply the wave equation including the time dependent wave operator [3,4], These methods are of 1st order accuracy in time, only, as we will show. We present a method which allows an accurate simulation of arbitrary lossless waveguide structures in integrated optics. This time domain method is based on an efficient explicit algorithm.

© 1994 Optical Society of America