Polariton Physics and Devices Pavlos G. Savvidis Dept of Materials Sci. & Tech Microelectronics Group University of Crete / IESL

dd Engineering Light Matter Interactions modify photonic and electronic wavefunctions in semiconductor heterostructures Confined electronic states: band gap energy modulation photons: refractive index modulation enhance, inhibit spontaneous radiation new properties, novel interactions, novel emitters AlAs GaAs AlAs e-e- high finesse cavity FORTH Microelectronics Research Group Univ. of Crete T δ QD

Weak Coupling Regime γ: loss channel (e.g. imperfect mirror) Ω coupling strength between optical transition of the material and the resonance photon mode Weak Coupling Regime (γ>>Ω) : emitted photon leaves the resonator (after some reflections) no reabsorption  Spontaneous Emission is irreversible FORTH Microelectronics Research Group Univ. of Crete γ Ω

Strong Coupling Regime γ: loss channel Ω coupling strength between optical transition of the material and the resonance photon mode Strong Coupling Regime (Ω>>γ) : emitted photon will be reabsorbed before it leaves the cavity  Spontaneous Emission is a reversible process Polaritons FORTH Microelectronics Research Group Univ. of Crete γ Ω

Research Activities GaAs Polariton LEDs & Lasers Strong Coupling in GaN Microcavties - common idea of engineering light matter interactions at nanoscale Bragg Polaritons Ultralow threshold lasers Robust polariton devices at RT Very strong nonlinearities Hybrid Organic-Inorganic LEDs

Temperature (K) X EL intensity C C X Energy (eV) Polariton Light Emitting Diode (LED) S.I. Tsintzos, N.T. Pelekanos, G. Konstantinidis, Z. Hatzopoulos, P. G. Savvidis, Nature 453, 372 (2008) Polariton electroluminescence up to room temperature

Strong exciton-Bragg mode coupling regime Bragg polaritons A. Askitopoulos et al., Phys. Rev. Lett. 106, (2011) 30K

People Prof. PG Savvidis Dr. Peter Eldridge Dr. Simos Tsintzos Dr. Manolis Trichas PhD Niccolo Somaschi PhD Panos Tsotsis PhD Tingge Gao PhD Kostas Daskalakis Alumni MS A. Askitopoulos MS C. Xenogianni MS N. Xatzidimitriou MS P. Tsotsis Collaborators Prof. Pelekanos Materials Prof. Z. Hatzopoulos Physics Prof. Iliopoulos Physics Prof. I Perakis Physics University of Durham Prof. M. Kaliteevski University of Sheffield Prof D. Lidzey Prof. J. J. Baumberg Dr. G. Christmann University of Cambridge University of Southampton Prof P. Lagoudakis Dr. G. Kostantinidis IESL Dr. G. Deligeorgis IESL Group

Funding EU FP7 : ITN grants “CLERMONT4” Polariton Lasers “ICARUS” Hybrid Materials National: PENED’03 GaN Microcavities Pythagoras II Organic Microcavities Herakleitos II Polariton Devices Industrial Mesophotonics Ltd. (PENED’03) Total Funding : ~ 1M Euro Principle Investigator in: A.Askitopoulos, Phys. Rev. Lett. 106, (2011) G. Christmann, Appl. Phys. Lett. 98, (2011) G Dialynas, J. Appl. Phys. 108, (2010) G. Christmann, Phys. Rev. B 82, (2010) E. Trichas, Appl. Phys. Lett. 94, (2009) S. I. Tsintzos, Appl. Phys. Lett. 94, (2009) G. E. Dialynas, Int. Jour.l of Nanotechnology 6, 124 (2009) S. I. Tsintzos, Nature 453, 372 (2008) Selected Publications

Ultrafast Lab

Polaritons are Bosons - Bose condensation - stimulated scattering Strong-coupling provides a new insight into a number of very interesting fundamental physical processes New Physics & Applications FORTH Microelectronics Research Group Univ. of Crete - ultralow threshold polariton lasers - all optical switches and amplifiers Polariton vs Photon Laser Deng, et al. Natl. Acad. Sci (2003)