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Excess Noise Generation During Spectral Boradening in Microstructure Fiber



J N. Ames, S Ghosh


We observe that nanojoule femtosecond pulses that are spectrally broadened in microstructure fiber acquire excess noise. The excess noise is namifest as an increase in the noise floor of the rf spectrum of the photocurrent from a photodetector illuminated by the pulse train from the oscillator. Measurements are made of the intensity dependence of the excess noise for both 100 fs and sub-10 fs pulses. The excess noise is very strong for 100 fs pulses, but barely measurable for sub-10 fs pulses. A rigorous quantum treatment of the nonlinear propagation of ultrashort pulses predicts that for a fixed generated bandwidth, the amount of excess noise decreases with pulse duration, in agreement with experimental results.
Applied Physics B


continuum generation, microstructure fiber


Ames, J. and Ghosh, S. (2003), Excess Noise Generation During Spectral Boradening in Microstructure Fiber, Applied Physics B (Accessed July 17, 2024)


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Created July 1, 2003, Updated February 17, 2017