Comparison of two flattening techniques on a double-pass erbium-doped superfluorescent fiber source for fiber-optic gyroscope

We experimentally compare the efficiency of two flattening techniques on the performances of a broad-band light source for fiber-optic gyroscope (FOG). The combination of a double-pass erbium-doped superfluorescent fiber source with a wavelength-selective reflector enables us to achieve the specifications needed for high-precision, navigational grade FOG: output power >18 mW, bandwidth of 30 nm, coherence length of 81 /spl mu/m.