Ambiguity function analysis of pulse train propagation: applications to temporal Lau filtering.
ABSTRACT We use the periodic-signal ambiguity function for visualizing the intensity-spectrum evolution through propagation in a first-order dispersive medium. We show that the degree of temporal coherence of the optical source plays the role of a low-pass filter on the signal's ambiguity function. Based on this, we present a condition on the temporal Lau effect for filtering harmonics at fractions of the Talbot length. This result allows one to increase the repetition rate of a pulse train obtained from a sinusoidally phase-modulated CW signal.
- SourceAvailable from: Carlos R. Fernandez-Pousa[show abstract] [hide abstract]
ABSTRACT: A spectral analysis of the temporal Talbot or self-imaging effect based on the exact computation of the radio frequency spectrum of the intensity of pulse trains after propagation in media with arbitrary first-order (β<sub>2</sub>) and second-order (β<sub>3</sub>) dispersion is presented. This allows the investigation of the performance of fiber dispersive lines as Talbot devices, where second-order dispersion is considered as a degradation factor. Conditions for repetition-rate multiplication and pulse compression over trains composed of linearly chirped Gaussian pulses, describing the effect as a filter in the intensity domain, are analyzed. The Talbot filter acts as a multiple bandpass filter that selects intensity harmonics. The filter's rejection capability depends on the train's spectral width normalized by the repetition-rate frequency of the output. The intensity fluctuations and pulse distortions of the output train are described from the spectral point of view. The tolerances of the filter under length and timing variations are also considered, and conditions for optimal filter stability are derived.Journal of Lightwave Technology 06/2006; · 2.56 Impact Factor
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ABSTRACT: A simple method for repetition-rate multiplication of optical pulses using uniform Bragg gratings is demonstrated. The grating formation system for this application requires positioning accuracy of only 1 μm. A simple method of control for each of the gratings in the writing process is proposed. Compensation of fiber dispersion using rate multiplication of pulses is also demonstrated.Optics Communications. 01/2003;