Marco Ornigotti, Alexander Szameit

The concept of quasi-PT symmetry in optical wave guiding system is elaborated by comparing the evolution dynamics of a PT-symmetric directional coupler and a passive directional coupler. In particular we show that in the low loss regime, apart for an overall exponentially damping factor that can be compensated via a dynamical renormalization of the power flow in the system along the propagation direction, the dynamics of the passive coupler fully reproduce the one of the PT-symmetric system.

http://arxiv.org/abs/1401.2299

Optics (physics.optics)

Alexander Szameit, Mikael C. Rechtsman, Omri Bahat-Treidel, Mordechai Segev

We apply gain/loss to honeycomb photonic lattices and demonstrate that optical tachyons, a photonic version of particles that travel faster than the speed of light, can be generated by PT-symmetry breaking in this structure. We further show that the PT-symmetry can be restored via strain.

http://arxiv.org/abs/1103.3389

Optics (physics.optics)

Alexander Szameit, Mikael C. Rechtsman, Omri Bahat-Treidel, Mordechai Segev

We apply gain/loss to honeycomb photonic lattices and show that the dispersion relation is identical to tachyons – particles with imaginary mass that travel faster than the speed of light. This is accompanied by PT-symmetry breaking in this structure. We further show that the PT-symmetry can be restored by deforming the lattice.

http://arxiv.org/abs/1103.3389

Optics (physics.optics)