Room-temperature Bose-Einstein condensation of cavity exciton-polaritons in a polymer.

A Bose-Einstein condensate (BEC) is a state of matter in which extensive collective coherence leads to intriguing macroscopic quantum phenomena. In crystalline semiconductor microcavities, bosonic quasiparticles, known as exciton-polaritons, can be created through strong coupling between bound electron-hole pairs and the photon field. Recently, a non-equilibrium BEC (ref.

Experimental methods of post-growth-tuning of the excitonic fine structure splitting in semiconductor quantum dots.

Deterministic sources of polarization entangled photon pairs on demand are considered as important building block for quantum communication technology. It has been demonstrated that semiconductor quantum dots (QDs), exhibiting a sufficiently small excitonic fine structure splitting (FSS) can be used as triggered, on-chip sources of polarization entangled photon pairs. As-grown QDs usually do not exhibit the required values of the FSS, making the availability of post-growth tuning techniques highly desired.

Epitaxial quantum dots in stretchable optical microcavities.

Arrays of GaAs microring optical resonators with embedded InGaAs quantum dots (QDs) are placed on top of Pb(Mg(1/3)Nb(2/3))O(3)-PbTiO(3) piezoelectric actuators, which allow the microcavities to be reversibly "stretched" or "squeezed" by applying relatively large biaxial stresses at low temperatures. The emission energy of both QDs and optical modes red- or blue- shift depending on the strain sign, with the QD emission shifting more rapidly than the optical mode with applied strain. The QD energy shifts are used to estimate the strain in the structures based on linear deformation potential theory and the finite element method.

Optical resonance tuning and polarization of thin-walled tubular microcavities.

We present experimental and finite-difference time-domain simulation results on the tunability of optical resonant modes of spiral microtube cavities, rolled-up from square patterned SiO/SiO(2) thin nanomembranes on glass substrates. The peak positions of resonant TM modes shift to lower energies by coating the microtube wall with Al(2)O(3) monolayers, which is well described by simulations. Moreover, a second group of tunable resonant modes appears beyond a certain critical thickness of the coated Al(2)O(3).