Electro-optical Michelson interferometer using low coherence fiber optics

We propose a novel application of superfluorescent fiber, or erbium doped fiber amplifier (EDFA), light sources (SFS) for radar systems. The ultra-wide band noise coupled with the use of optical fiber delay lines makes SFS ideally suited for random noise radar applications. Optical fiber makes long and multiple-step delay lines of a few kilometers feasible. Its advantage includes being extremely low-loss, compact and light-weighted, and available at a much lower cost, while avoiding the dispersion and non-linearity associated with microwave delay lines. In our experiments, the erbium-doped fiber is pumped by a distributed feedback laser operating at 980 nm and generates broadband light at 1550 nm. This low coherence light source is employed in a novel microwave electro-optical Michelson interferometer arrangement to demonstrate the feasibility of the radar application. We report the theoretical analysis and experimental results to characterize the resolution characteristics of the systems