Nonlinear Dynamics in Semiconductor Lasers Due to Filtered Optical Feedback: Fundamental Issues, and Applications to Chaotic Encryption and Signal Routing

Indiana University, Bloomington IN

Investigators

Abstract

This proposal proposes a three year program of studies on nonlinear dynamics in diode lasers that arise from filtered optical feedback (FOF). FOF differs from conventional feedback (COF) in that the feedback light is spectrally filtered by an optical element that is external to the laser, before coupling back into the laser. The alterations in the dynamics due to FOF, when compared to COF are quite dramatic; more significantly, the proposal provides clear evidence of how FOF can be used to control the dynamics of the laser. Such control can be used to force the laser into regions of the dynamical phase space where it exhibits a desired dynamical response. In addition to the fundamental scientific issues that are inherent to FOF in diode lasers, the application of the control capability towards two ends will be explored. These are chaotic encryption and signal routing. In case of the former, the emphasis will be on making the wavelength of the laser light chaotic, and then controlling the bandwidth of the chaotic fluctuations. The direct impact of the work will be on telecom systems, and the infrastructure that is critical to all-optical communication systems. A successful completion of the project may spur the telecommunications industry to view FOF as a possible control mechanism for tailoring the dynamical response of diode lasers. The broader impact will be on the laser dynamics community, and especially those that are studying issues like COF, optical injection, and bifurcations in diode lasers. In addition, because FOF is a prototypical laboratory example of logistic maps, and a test bed for mathematical models that rely on time-delayed equations, it's anticipated that the applied mathematics and nonlinear dynamics community will be influenced by this work.