Excess noise generation during spectral broadening in a microstructured fiber
ABSTRACT We observe that nanojoule femtosecond pulses that are spectrally broadened in a microstructured fiber acquire excess noise. The excess noise is manifested as an increase in the noise floor of the rf spectrum of the photocurrent from a photodetector illuminated by the pulse train from the laser oscillator. Measurements are made of the intensity dependence of the excess noise for both 100fs and sub-10fs pulses. The excess noise is very strong for 100fs pulses, but barely measurable for sub-10fs 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 the experimental results.
Full-textDOI: · Available from: Alexander Gaeta, Mar 11, 2014
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ABSTRACT: In the past decade we have witnessed remarkable advances associated with the frequency stabilization of the comb present in the output of a mode-locked femtosecond laser. While proving itself to be fantastically successful in its role as the “gears” of optical atomic clocks, the optical frequency comb has further evolved into a valuable tool for a wide range of applications, including ultraviolet and infrared spectroscopy, frequency synthesis, optical and microwave waveform generation, astronomical spectrograph calibration, and attosecond pulse generation, to name a few. In this review, I will trace several of these developments while attempting to offer perspective on the challenges and opportunities for frequency combs that might lie ahead in the next decade.Journal of the Optical Society of America B 01/2010; DOI:10.1364/JOSAB.27.000B51 · 1.81 Impact Factor
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ABSTRACT: The ability to generate a supercontinuum in microstructure fiber using only the unamplified pulses from a mode-locked oscillator was critical to the development of optical frequency combs. I will briefly introduce the key concepts for stabilizing the comb spectrum of a mode-locked laser and how it relies on continuum generation.Proceedings of SPIE - The International Society for Optical Engineering 02/2014; DOI:10.1117/12.2030615 · 0.20 Impact Factor