Ultrashort Pulse Characterization

Hosted By: Nonlinear Optics Technical Group

15 April 2020, 11:00 - 12:00 - Eastern Daylight Time (UTC - 04:00)

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Recent years have witnessed a tremendous progress in the generation of ultra-broadband few-optical-cycle pulses. Accurate characterization of the temporal profile of pulses with such extreme bandwidth and broad frequency tunability poses a severe experimental challenge. How to measure a light pulse, which is itself among the shortest artificial events ever generated by mankind?

One answer comes from the Fourier transform concept, which states that the frequency domain holds valuable information. This is particularly promising in optics, in which the frequency domain is not just a concept but it is the natural domain of the light spectrum. Measuring light pulses in the frequency domain is truly the practical key to access the challenging information of their shape. The Fourier transform provides a complex function; its amplitude is the weight of each component and is easily accessible by spectrometers; the spectral phase is their mutual delay. It turns out that the phase stores most of the information of the pulse shape, but it is also the most difficult information to measure.

This webinar hosted by the OSA Nonlinear Optics Technical Group will explore this concept and intriguing techniques required for a reliable measurement of the spectral phase. The webinar will study two main paradigms: frequency resolved techniques and shearing interferometers, reviewing some experimental implementations and the phase-retrieval methods.

What You Will Learn:

  • Measuring a pulse is mainly measuring its spectral phase
  • Manipulating a pulse is mainly manipulating its spectral phase 
  • Extraction of the spectral phase requires second order nonlinear processes
  • How frequency resolved techniques and shearing interferometers work

Who Should Attend:

  • People interested in the characterization and manipulation of optical pulses
  • Researchers who want to learn how to build a FROG, a SPIDER, or any other nonlinear device from the broad zoo of pulse characterization techniques

About the Presenter: Cristian Manzoni, CNR-IFN, Politecnico di Milano

Cristian Manzoni is a researcher of the Istituto di Fotonica e Nanotecnologie (IFN) of CNR (Italy) working in the field of nonlinear optics and spectroscopy. He received his Ph.D. in 2006 from Politecnico di Milano (Italy) on ultrafast laser physics. During his post-doc research at the Deutsches Elektronen-Synchrotron in Hamburg (Germany) he worked on free electron laser science. In 2009 he joined the CNR and he is an expert in the generation of ultrafast laser pulses with tunable spectrum from infrared to XUV, up to few-cycle duration, phase-stabilized and with controlled wavefront. His goal includes the development of novel methods for ultrashort pulses control and for time-resolved studies of a vast range of systems: from bio-composites to low-dimensional and strongly correlated materials. His reasearch interest extends also to time-resolved microscopy and hyperspectral imaging applied to two-dimensional crystals and for cultural heritage studies.