Electrically Tunable Optical Delay Lines.

摘要

In this report, we detail the methodology and results for design, fabrication, and characterization of electrically tunable optical delay lines. Our approach focuses on monolithic semiconductor multilayer heterostructures (Distributed Bragg Reflector) to produce true time delays for incident transmitted optical pulses. Quantum wells are grown in every other layer of the DBR stack. When a field is applied across the device, the well-known Quantum Confined Stark Effect causes both absorption and refractive index changes in these layers. Changing the field changes the effective optical path length, thereby providing electrically tunable true time delays. In-house design, growth, and processing were all accomplished by AFRL. Simple broadband transmission characteristics were also performed in-house, while true-time delay experiments were performed exclusively by collaborators from the University of Alabama at Huntsville.