High Dynamic Range Fiber-Optic Link for C3I Applications

For Navy's multi-function phased array antenna systems, in order to serve the command, control, communication and intelligence(C3I) functions, high spurious-free dynamic range fiber optic link is a prerequisite. Current state of the art F-0 links using LiNbO3 Mach Zehnder external modulator can only achieve about 108 dB/Hz2/3. Electroabsorption modulator, on the other hand, has been demonstrated to provide 120 dB/Hz2/3 dynamic range in a non- optimized link. In this proposal we intend to optimize the modulator as well as the wide band detector to achieve 140 dB link dynamic range without sacrificing its microwave bandwidth capability. Approaches to achieve the improvement will be through device design to increase the optical power handling capacity and coupling efficiency to single mode fiber. Since both the EA modulator and the waveguide detector share much similarity in structure, certain design improvement can apply to both.