Discrete modeling of optical pulse propagation in nonlinear media. Final report

Abstract

With the continuing and heightened interest in nonlinear semiconductor and optically integrated devices, more accurate and realistic numerical simulations of these devices and systems are in demand. Such calculations provide a testbed in which one can investigate new basic and engineering concepts, materials, and device configurations before they are fabricated. This encourages multiple concept and design iterations that result in enhanced performances and system integrations of those devices. They also provide a framework in which one can interpret complex experimental results and suggest further diagnostics or alternate protocols. Thus the time from device conceptualization to fabrication and testing could be enormously improved with numerical simulations that incorporate more realistic models of the linear and nonlinear material responses and the actual device geometries. The authors have successfully developed a finite difference time domain method that simulates the propagation of ultra-short optical pulses in nonlinear materials which can be described with a linear Lorentz dispersion model, an instantaneous nonlinear Kerr model and a retarded nonlinear Raman model. They have used this NL-FDTD method to model and characterize several ultra-short optical pulse configurations including linear and nonlinear optical waveguides that could be used as all-optical output couplers and beam steerers.