Low coherence reflectometry using wavelength-tunable superfluorescent fibre source

A wavelength-tunable superfluorescent fibre source with an erbium-doped fibre amplifier was constructed to reduce the jaggedness in low coherence reflectometry. This source was capable of tuning narrowband superfluorescence ( approximately 1 nm FWHM) over a 32 nm range with an output of 4.3 dBm. The signal averaging which resulted from wavelength tuning with this source efficiently reduced the jagged fluctuation in the Rayleigh backscattering profile to +or-1 dB. The advantage of signal averaging over conventional signal smoothing is also discussed.