Dispersion requirements in coherent frequency-to-time mapping

The article of record as published may be located at https://doi.org/10.1364/OE.19.024718Funded by Naval Postgraduate SchoolThe frequency-to-time mapping technique (also known as the temporal far-field phenomenon) usually requires a significant amount of dispersion to stretch an ultrashort optical pulse so that the intensity profile becomes a scaled replica of its optical spectrum. In this work, we study the near-to-far-field transition and find that the far-field condition can be relaxed in some cases relevant for radio-frequency (RF) waveform generation. This observation has allowed us to achieve intensity signals with an ultrabroad RF bandwidth content.This project was supported in part by the Naval Postgraduate School under grant N00244-09- 1-0068 under the National Security Science and Engineering Faculty Fellowship program.This project was supported in part by the Naval Postgraduate School under grant N00244-09- 1-0068 under the National Security Science and Engineering Faculty Fellowship program

Fast Characterization of Dispersion and Dispersion Slope of Optical Fiber Links using Spectral Interferometry with Frequency Combs

We demonstrate fast characterization (~1.4 microseconds) of both the dispersion and dispersion slope of long optical fiber links (~25 km) using dual quadrature spectral interferometry with an optical frequency comb. Compared to previous spectral interferometry experiments limited to fiber lengths of meters, the long coherence length and the periodic delay properties of frequency combs, coupled with fast data acquisition, enable spectral interferometric characterization of fibers longer by several orders of magnitude. We expect that our method will be useful to recently proposed lightwave techniques like coherent WDM and to coherent modulation formats by providing a real time monitoring capability for the link dispersion. Another area of application would be in stabilization of systems which perform frequency and timing distribution over long fiber links using stabilized optical frequency combs.Comment: 3 pages, 3 figures, Minor changes to tex

Single Shot Amplitude and Phase Characterization of Optical Arbitrary Waveforms

Using a time-gated dual quadrature spectral interferometry technique, for the first time we demonstrate single-shot characterization of both spectral amplitude and phase of ~1THz bandwidth optical arbitrary waveforms generated from a 10 GHz frequency comb. Our measurements provide a temporal resolution of 1ps over a record length of 100ps. Singleshot characterization becomes particularly relevant when waveform synthesis operations are updated at the repetition rate of the comb allowing creation of potentially infinite record length waveforms. We first demonstrate unambiguous single shot retrieval using rapidly updating waveforms. We then perform additional single-shot measurements of static user-defined waveforms generated via line-by-line pulse shaping.Comment: 10 pages, 6 figures. Added new references and minor changes to tex

Dispersion requirements in coherent frequency-to-time mapping

The frequency-to-time mapping technique (also known as the temporal far-field phenomenon) usually requires a significant amount of dispersion to stretch an ultrashort optical pulse so that the intensity profile becomes a scaled replica of its optical spectrum. In this work, we study the near-to-far-field transition and find that the far-field condition can be relaxed in some cases relevant for radio-frequency (RF) waveform generation. This observation has allowed us to achieve intensity signals with an ultrabroad RF bandwidth contentThis project was supported in part by the Naval Postgraduate School under grant N00244-09- 1-0068 under the National Security Science and Engineering Faculty Fellowship program. Any opinion, findings, and conclusions or recommendations expressed in this publication are those of the authors and do not necessarily reflect the views of the sponsors. Victor Torres- Company gratefully acknowledges funding from a Marie Curie International Outgoing fellowship (project PIOF-2009-234996

Comb-based radio-frequency photonic filtering with 20 ns bandwidth reconfiguration

Optics LettersThe article of record as published may be found at http://dx.doi.org/10.1364/ol.38.002735We present a scheme to generate a 10 GHz optical frequency comb that is bandwidth reconfigurable on a time scale of tens of nanoseconds via electronic control of the drive signal to a phase modulator. When such a comb is used as the source for a radio-frequency (RF) photonic filter employing dispersive propagation, the RF filter bandwidth varies in inverse proportion to the optical bandwidth. As a result we are able to demonstrate, for the first time to our knowledge, bandwidth-reconfigurable RF filtering with transition times under 20 ns. The reconfiguration speed is determined by the response time of a programmable RF variable attenuator.Funded by Naval Postgraduate SchoolThis project was supported in part by the Naval Postgraduate School under grant N00244-09-1-0068 under the National Security Science and Engineering Faculty Fellowship progra