CHARACTERISTICS OF ERBIUM-DOPED SUPERFLUORESCENT FIBER SOURCES FOR INTERFEROMETRIC SENSOR APPLICATIONS

The fcharacteristics of 1.55 mum Er-doped superfluorescent fiber sourc es (SFS's), intended for fiber-optic gyroscope (FOG) applications, are explored theoretically and experimentally. With proper selection of t he source configuration, fiber length, pump wavelength, pump power, an d fiber composition, we show that it is possible to meet the stringent requirements of the FOG, including a high output power, broad emissio n bandwidth, and excellent spectral thermal stability. Variations of t he mean wavelength, spectral width, and output power of the SFS with f iber length, pump power, pump wavelength, and temperature are modeled for representative sources pumped near 980 nm or 1.48 mum, and are sho wn to be in good agreement with experimental results. The effects of a multimoded pump, erbium ion pair, and optical feedback are also asses sed. This study indicates that the Er-doped SFS is an excellent candid ate for the FOG and for other applications requiring spatial coherence and low temporal coherence.