Polariton Physics and Devices

Pavlos G. Savvidis

Dept of Materials Sci. & TechMicroelectronics GroupUniversity of Crete / IESL

d

Engineering Light Matter Interactions

• modify photonic and electronic wavefunctionsin 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-

high finessecavity

FORTH Microelectronics Research Group Univ. of Crete

T

δ

QD

Weak Coupling Regime

γ: loss channel (e.g. imperfectmirror)

Ω coupling strength betweenoptical transition of the material andthe 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

γΩ

Strong Coupling Regime

γ: loss channel

Ω coupling strength betweenoptical transition of the material andthe 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

γΩ

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

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1.3601.3551.3501.3451.3401.3351.330

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pera

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X

EL intensity

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C

X190

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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, 076401 (2011)

30K

People

Prof. PG SavvidisDr. 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 SheffieldProf D. Lidzey Prof. J. J. Baumberg

Dr. G. Christmann

University of Cambridge

University of SouthamptonProf P. Lagoudakis

Dr. G. Kostantinidis IESLDr. G. Deligeorgis IESL

Group

Funding

EU FP7 : ITN grants

2009-2013 “CLERMONT4” Polariton Lasers2009-2013 “ICARUS” Hybrid Materials

National: 2005-2010 PENED’03 GaN Microcavities2006-2010 Pythagoras II Organic Microcavities2010-2013 Herakleitos II Polariton Devices

Industrial Mesophotonics Ltd. (PENED’03)

Total Funding 2005-2010 : ~ 1M Euro

Principle Investigator in:

A. Askitopoulos, Phys. Rev. Lett. 106, 076401 (2011)G. Christmann, Appl. Phys. Lett. 98, 081111 (2011)G Dialynas, J. Appl. Phys. 108, 103525 (2010)G. Christmann, Phys. Rev. B 82, 113308 (2010)E. Trichas, Appl. Phys. Lett. 94, 173505 (2009)S. I. Tsintzos, Appl. Phys. Lett. 94, 071109 (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 LaserDeng, et al. Natl. Acad. Sci. 15318 (2003)