FDTD analysis of wave propagation in nonlinear absorbing and gain media (original) (raw)
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Abstract
An explicit finite-difference time-domain (FDTD) scheme for wave propagation in certain kinds of nonlinear media such as saturable absorbers and gain layers in lasers is proposed here. This scheme is an extension of the auxiliary differential equation FDTD approach and incorporates rate equations that govern the time-domain dynamics of the atomic populations in the medium. For small signal intensities and slowly varying pulses, this method gives the same results as frequency-domain methods using the linear susceptibility function. Population dynamics for large signal intensities and the transient response for rapidly varying pulses in two-level (absorber) and four-level (gain) atomic media are calculated to demonstrate the advantages of this approach.
Publication:
IEEE Transactions on Antennas and Propagation
Pub Date:
March 1998
DOI:
Bibcode:
Keywords:
- Finite difference methods;
- Time domain analysis;
- Nonlinear equations;
- Maxwell equations;
- Atomic measurements;
- Optical propagation;
- Differential equations;
- Atomic beams;
- Electromagnetic propagation;
- Frequency