Modeling of pulse propagation in a four level atomic medium for gyroscopic measurements

We propose to develop numerical methodologies that can be used as alternatives to standard finite-difference time-domain algorithms, and that will offer substantial reductions in numerical complexity (notably CPU-time requirements) without the need to trade-off flexibility for overall robustness. In the initial phase, we propose a two-pronged approach, in which we evaluate two alternatives: (i) a time-dependent transfer matrix (TDTM) approach; and (ii) a slowly-varying envelope function (SVE) approach. In Phase I, we will develop both methodologies, assess their performance characteristics, and choose the best for continued development. Comparative evaluations will be done by numerically solving the relevant equations and comparing performance with currently existing Navy codes. Both proposed methods (TDTM and SVE) are suitable for dealing with co- and counter-propagating beams, and for including the full nonlinear interaction between light fields and four-level N-scheme atomic systems. Hence, both schemes are suitable for simulating ring-resonator gyroscopes with Sagnac phase enhancements due to EIT-like quantum coherences. In Phase II, we would develop a full-scale numerical model, and, if requested, fabricate a prototype fiber-optic gyroscope based on NP Photonics"specialty fiber, and fiber laser capabilities.