Temporal imaging is a technique that enables manipulation of temporal optical signals in a manner similar to manipulation of optical images in spatial domain. It uses the notion of space-time duality with dispersion phenomena playing the role of diffraction and quadratic phase modulation in time acting as a time lens.In this work we address the problem of temporal imaging of a temporally broadband squeezed light generated by a traveling-wave optical parametric amplifier or a similar device. We consider a single-lens temporal imaging system formed by two dispersive elements and a parametric temporal lens, based on a sum-frequency generation process. We derive a unitary transformation of the field operators performed by this kind of time lens. We evaluate the squeezing spectrum at the output of the single-lens imaging system and find the conditions preserving squeezing in the output field. When the efficiency factor of the temporal lens is smaller than unity, the vacuum fluctuations deteriorate squeezing at its output. For efficiency close to unity, when certain imaging conditions are satisfied, the squeezing spectrum at the output of the imaging system will be the same as that at the output of the OPA. This scheme gives the possibility of matching the coherence time of the broadband squeezed light to the response time of the photodetector. We finally discuss a temporal imaging scheme which allows to partially compensating the frequency dispersion of the OPA.
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Mikołaj Kajetan Schmidt (CSIC-UPV EHU San Sebastian, Spain)
Among a number of spectroscopic techniques developed to characterize the electronic and vibrational structure of atoms and molecules, one - Substrate Enhanced Raman Scattering (SERS) - has taken hold in a rather unexpected territory of plasmonics. Plasmonics resonances occur in metallic nanostructures as the free electron gas sloshes within the metal, in response to the electric field of incident light, creating the so-called "hot-spots" - tiny volumes near the metal surface in which the intensity of incident illumination is amplified by orders of magnitude. While this effect can be directly used to enhance the light-matter interaction, its applicability is suppressed by the extremely lossy nature of plasmonic excitations, resulting in extremely low populations of plasmons.Nevertheless, very recent implementations of SERS experiments [1] appear to provide results which escape the standard semi-classical description of the Raman process based on the classical treatment of the electromagnetic enhancement of fields in these hot-spots [2]. To address these issues, we have proposed a novel theoretical framework, inherited from the community of quantum cavity optomechanics [3-5] and applied it to predict a plethora of effects which are not encompassed by the semi-classical framework. This approach allows us to discuss the coherences of the non-linear scattering processes, role of vacuum fluctuations of the plasmon population on the vibrational pumping of molecules, etc. [5-7] By reciprocity, we show that SERS constitutes a very atypical implementation of the optomechanical dynamics, placing it in the largely unexplored regime of THz mechanical frequencies, low-Q "bad" cavities and large single-photon couplings.[1] R. Zhang, et al., Nature 498, 82 (2013).[2] H. Xu, et al., Phys. Rev. Lett. 93, 243002 (2004).[3] P. Roelli, et al., Nat. Nano. 11, 164 (2016).[4] M.K. Schmidt and J. Aizpurua, Nature Nanotech. 11, 114 (2016).[5] M.K. Schmidt, et al., ACS Nano 10, 6291 (2016).[6] M.K. Schmidt, et al., in preparation.[7] F. Benz, M.K. Schmidt, et al., Science, in press (2016).
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Matteo Paris (Universita degli Studi di Milano)
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Jarosław Korbicz (Politechnika Gdanska, Krajowe Centrum Informacji Kwantowej)
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Thomas Udem, Paolo Mataloni, Fedor Jelezko, Pierre Chavel (UWAGA: Wykłady odbywają się w budynku CeNT III, Aula C)
09:30–13:00 /Thomas Udem (Max-Planck Institut für Quantenoptik): Challenging QED with precision measurements on atomic hydrogen /Paolo Mataloni (Sapienza Università di Roma):On-chip multiqubit photonic cluster states /Fedor Jelezko (Universität Ulm): Interfacing single photons and single spins in diamond /Pierre Chavel (Institut d’Optique): Flat opticsin a historical perspective
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Mikołaj Lasota (UMK Toruń)