Finite-difference time-domain calculation of spontaneous emission lifetimein a microcavity

We developed a general numerical method to calculate the spontaneous emissi on lifetime in an arbitrary microcavity, using a finite-difference time-dom ain algorithm. For structures with rotational symmetry we also developed a more efficient but less general algorithm. To simulate an open radiation pr oblem, we use absorbing boundaries to truncate the computational domain. Th e accuracy of this method is limited only by numerical error and finite ref lection at the absorbing boundaries. We compare our result with cases that can be solved analytically and find excellent agreement. Finally, we apply the method to calculate the spontaneous emission lifetime in a slab wavegui de and in a dielectric microdisk, respectively. (C) 1999 Optical Society of America [S0740-3224(99)00403-8]. OCIS codes: 000.4430, 230.3990, 270.5580.