Chaotically Controlled Semiconductor Laser Arrays

The following proposal contains an innovative design for a semiconductor laser source that could significantly improve the reliability and performance of future ballistic missile defense systems. Next generation theater and national missile defense systems require reliable semiconductor laser sources with output power and brightness greater than those of current devices. Current devices have limited output power due to excessive optical absorption on the laser's facets. Semiconductor laser arrays offer a potential solution to this optical absorption limitation. The problem with these arrays are their temporal instabilities resulting in "desychronization" of the array system. Multi-element laser arrays are complex systems exhibiting highly nonlinear and chaotic behavior in certain domains. Recent developments in "chaos" theory give us an opportunity to solve this temporal instability problem by utilizing the intrinsic properties of its chaotic attractor. These attractors contain an infinite number of unstable periodic orbits none of which exclusively dominate. By making small changes to the system, the goal is to synchronize the laser array by selectively stabilizing an existing, albeit unstable, periodic orbit embedded in the attractor. Our Phase I research objective is to examine the feasibility of controlling the laser array's chaotic behavior through numerical simulation of an array model. Successful completion of our project will result in improved semiconductor laser sources used in DoD and commercial applications including, but not limited to, fiberoptic communications networks, integrated optoelectronics, avionics, laser RADAR, 3D imaging, short range vision systems, and free space optical communications.