Day 1 :
ITMO University, Russia
Time : 08:35-09:05
The promising approaches for multi-mode optical quantum memory and its use in quantum processing and communication are discussed. Herein, we are interested in specific properties of the recently developed photon echo schemes in solid state and gaseous media. The photon echo approach opened a number of convenient protocols for storage of multi-mode light fields such as well-known CRIB-, GEM- and AFC-protocols and approaches using atomic systems with natural inhomogeneous broadening of resonant transitions such as ROSE-type –protocols. We discuss basic properties, advantages and difficulties of these protocols, new experimental achievements in these schemes and possible progress in its future development. Here we consider new realizations using particular properties of resonant systems used for quantum storage and different types of the light-atom interactions. At first, we propose convenient experiment realizations of efficient broadband ACF-protocol. A special attention, we paid to off-resonant Raman interaction of light fields with atomic systems for considerable improvement of the photon echo QM schemes. Here, we discuss new properties of the Raman echo QM in free space and in the optical cavity schemes. In particular, we are interested in the properties of multi-color, associate multi-mode QM, and efficient wavelength conversion. Also, we elaborate new approach for realization of broadband photon echo quantum storage in optical cavity. In our analysis, we discuss importance and role of time-reversal dynamics in the light-atom interactions for high quantum efficiency and fidelity in light field storage. Finally, we discuss a potential realization of the studied photon echo schemes in the planed experiments on the inorganic crystals doped by rare-earth ions and potential application of these schemes for quantum repeaters and quantum processing.
CCJ Software, Germany
Time : 09.30-010.20
KTH – Royal Institute of Technology, Sweden
Time : 09:35-10:20
Markus Pollnau received MSc and PhD degrees in Physics from University of Hamburg, Germany (1992) and University of Bern, Switzerland (1996), respectively. In 2004, he became a Full Professor at the University of Twente, The Netherlands and moved to KTH, Sweden, in 2014. He has contributed to more than 500 reviewed journals and international conference papers on crystal and thin-film growth, rare-earth-doped lasers and waveguide fabrication, devices and applications. He served as General Co-chair of the Conferences on Lasers and Electro-Optics (2008), Lasers and Electro-Optics Europe (2011) and the Europhoton Conference (2004). He is a fellow of OSA and EPS.
Rare-earth ions have been widely exploited for amplification and lasing on various electronic transitions from the near-ultraviolet to the mid-infrared spectral region. The small transition cross sections of rare-earth ions result in a large absorption length of pump light, thus dictating an accordingly long interaction length with the active material to exploit the delivered pump power. In the past two decades, waveguide geometries that rely on the total internal reflection of pump and signal light on their propagation through the active material have become very successful. These geometries allow for tight pump- and signal-light confinement, hence high optical pump intensities and excellent overlap between pump and signal beam over very long interaction lengths, thereby ensuring good pump absorption and enabling a low threshold and high efficiency. The excellent performance of these devices is based on careful analysis and exploitation of the specific spectroscopic properties of the utilized rare-earth ion. Recent examples include a Tm-doped potassium double tungstate channel waveguide laser with an active ion concentration of 8%, thus ensuring efficient cross relaxation of 800-nm-pump excitation and resulting in record-high slope efficiency for any Tm-doped laser of ~80%. Furthermore, distributed-feedback and distributed-Bragg-reflector narrow-linewidth channel waveguide lasers were demonstrated in Er- and Yb-doped amorphous aluminum oxide on a silicon wafer by inscribing a uniform Bragg grating into the silicon oxide top cladding, with laser linewidths down to 1.7 kHz and slope efficiencies up to 67%.