[RpL 995] Fwd: Open RQC Colloquium. Lecture 21

Вт Апр 4 11:34:39 MSK 2017

   -------- Forwarded Message --------
    Subject: Open RQC Colloquium. Lecture 21
       Date: Mon, 3 Apr 2017 13:30:48 +0000
       From: Russian Quantum Center information [1]<info на rqc.ru>
   Reply-To: [2]us4-8b8a06201b-14bee41628 на conversation01.mailchimpapp.com
         To: [3]akorneev на rplab.ru

Open RQC Colloquium. Lecture 21

   [a7153ab5-4dc7-4d2c-9a7d-4a9da6ac70e5.jpg] The Twenty First
   lecture "Nonlinear-optical methods for the terahertz-wave generation
   and detection" in "Open RQC colloquium" will be held in [4]National
   University of Science and Technology MISIS (Moscow, Leninskiy prospekt
   4) lecture hall No. B-536 (5th floor), on 7th of April 2017 at 10:00
   a.m by [5]Galiya Kitaeva, a leader of Quantum Phenomena in Optical and
   Terahertz Ranges Laboratory at the MSU Chair of Quantum Electronics.
   Abstract

   Electromagnetic radiation of the terahertz frequency range (0.1-10
   THz) attracts a growing interest due to variety of promising possible
   applications in spectroscopy, communication, biomedical imaging,
   security systems and others. Nevertheless, for a long time this range
   was called as a "terahertz gap" closed for the use and exploration. Up
   to now the progress in both effective generation and sensitive
   detection methods that could be arranged in simple low-cost and
   easily-accessible compact devices is crucial for success of the most
   applications. This motivates specialists from various fields of
   physics to develop new ideas for creating the terahertz devices. Among
   different approaches, the nonlinear-optical methods are in the
   forefront for the last few decades. Based on conversion of optical
   energy of visible and NIR lasers into the THz gap, they are
   advantageous not only due to room-temperature generation of coherent
   directional THz radiation, but also due to possibilities of
   instantaneous detection using inverse frequency-conversion process.
   After a brief review of the generation methods, in the lecture I will
   discuss how engineering of nonlinear-optical quasi-phase-matched
   structures may be used to control the spectrum of terahertz generation
   under optical rectification of both femtosecond and nanosecond laser
   pulses. The second part of the lecture concerns detection of short
   terahertz pulses in the terahertz time-domain spectroscopic schemes
   (usually named as electro-optic sampling) and incoherent
   nonlinear-optical detection of continuous-wave radiation.
   In a standard electro-optic sampling scheme, the phase changes of
   polarization components of the laser radiation are measured, induced
   by the terahertz electric field in a nonlinear crystal, which
   necessarily should be of the zinc-blende symmetry. However, the use of
   crystals of other symmetries, with stronger nonlinearity but higher
   natural birefringence, is hindered. It will be shown that such
   crystals can be used in a simpler "probe-energy" scheme, where the
   terahertz-induced parameter under measurement is an energy change of
   the transmitted probe pulse. Due to special spectral filtering of the
   femtosecond optical pulses, this simple scheme can be sufficiently
   more sensitive than the standard one. Substantial improvement of
   sensitivity, up to 2 orders of magnitude, has been achieved recently.
   The incoherent detection via parametric up-conversion of the terahertz
   frequency is free of any restrictions imposed by the mode of the THz
   wave generation. Requirements to the pump power are not as high as in
   case of nonlinear-optical THz generation, and we demonstrate
   spectrally resolved room-temperature detection of continuous wave
   source using 100 mW laser radiation as a pump. Fluctuation fields at
   idler (terahertz) frequencies are detected also as background "noise"
   signals at optical output frequencies of the nonlinear-optical
   parametric up-convertor. These signals appear in the anti-Stokes part
   of the spectrum due to sum-frequency generation process between
   thermal fluctuations and pump fields, and in the Stokes part of the
   spectrum due to difference-frequency generation and spontaneous
   parametric down-conversion of the pump radiation. Possibility of
   calibration of spectral brightness of terahertz sources will be
   discussed considering as references the brightness of classical
   thermal fluctuations and the effective brightness of quantum zero
   vacuum fluctuations.

   Biography

   Galiya Kitaeva graduated from Lomonosov Moscow State University (MSU)
   in 1976. Working at MSU since graduation, she studied applications of
   spontaneous parametric down-conversion effect in quantum photometry
   and spectroscopy of phonon polaritons, also taking advantage of the
   nonlinear-optical processes in periodically poled crystals and other
   spatially inhomogeneous solid structures. In 1982 she received PhD and
   in 2002 received her Doctor of Science Degree, both in MSU. She was a
   visiting Professor at National University of Singapore, Paderborn
   University, Friedrich-Alexander-UniversitДt Erlangen-NЭrnberg. Since
   2006 develops new methods for the terahertz wave generation, detection
   and spectroscopy. Starting from 2016 Galiya is a leader of Quantum
   Phenomena in Optical and Terahertz Ranges Laboratory at the MSU Chair
   of Quantum Electronics.

   Please don't forget to take passport for entering to the University.
   We will meet you at the guard desk.

   FREE ENTRANCE.

   [da839237-45aa-4157-9c49-b75cac089e91.jpeg]

   If you have any questions, please e-mail to
   Ksenia [6]k.kolesnik на rqc.ru
   [7][outline-color-facebook-48.png] [8]Share
   [9][outline-color-twitter-48.png] [10]Tweet
   [11][outline-color-forwardtofriend-48.png] [12]Forward to Friend
   Copyright ╘ 2017 RQC, All rights reserved.
   Vy poluchili `eto pis'mo tak kak yavlyaetes' podpischikom nashej
   rassylki.
   Our mailing address is:
   RQC
   Business Center ╚Ural╩, 100, Novaya st.
   Skolkovo 143025
   Russia
   [13]Add us to your address book
   [14]unsubscribe from this list    [15]update subscription preferences

   [open.php?u=8108e48f6c1a81eeb480bf510&id=73466f814d&e=59b6fc18
   41]

References

   1. mailto:info на rqc.ru
   2. mailto:us4-8b8a06201b-14bee41628 на conversation01.mailchimpapp.com
   3. mailto:akorneev на rplab.ru
   4. http://rqc.us4.list-manage.com/track/click?u=8108e48f6c1a81eeb480bf510&id=724ea5d8e2&e=59b6fc1841
   5. http://rqc.us4.list-manage.com/track/click?u=8108e48f6c1a81eeb480bf510&id=aa48554b5e&e=59b6fc1841
   6. mailto:k.kolesnik на rqc.ru
   7. http://rqc.us4.list-manage.com/track/click?u=8108e48f6c1a81eeb480bf510&id=679929273a&e=59b6fc1841
   8. http://rqc.us4.list-manage.com/track/click?u=8108e48f6c1a81eeb480bf510&id=05ec68a612&e=59b6fc1841
   9. http://rqc.us4.list-manage1.com/track/click?u=8108e48f6c1a81eeb480bf510&id=03899a7c64&e=59b6fc1841
  10. http://rqc.us4.list-manage1.com/track/click?u=8108e48f6c1a81eeb480bf510&id=414b6046d0&e=59b6fc1841
  11. http://us4.forward-to-friend.com/forward?u=8108e48f6c1a81eeb480bf510&id=73466f814d&e=59b6fc1841
  12. http://us4.forward-to-friend.com/forward?u=8108e48f6c1a81eeb480bf510&id=73466f814d&e=59b6fc1841
  13. http://rqc.us4.list-manage.com/vcard?u=8108e48f6c1a81eeb480bf510&id=5ee8ed5ff4
  14. http://rqc.us4.list-manage.com/unsubscribe?u=8108e48f6c1a81eeb480bf510&id=5ee8ed5ff4&e=59b6fc1841&c=73466f814d
  15. http://rqc.us4.list-manage.com/profile?u=8108e48f6c1a81eeb480bf510&id=5ee8ed5ff4&e=59b6fc1841