Noam Kaminski

Negative dispersion: a backward wave or fast light? Nanoplasmonic examples

Propagation of light in a negative dispersion regime (antiparallel phase and group velocities) may be attributed to either fast light or a backward wave. We show that by applying causality, only one of these is valid for each scenario. A nanoplasmonic structure is shown to support both types of solution depending on the parameters.

Numerical Study of Few-Cycle Pulses by Nonlinear Compression in Two-Photon Semiconductor Amplifiers

Optical pulse compression down to a few optical cycles by the ultrabroadband gain of nonlinear two-photon process in semiconductors is proposed. Recent experimental demonstration of semiconductor two-photon gain (TPG) has motivated this analysis of ultrashort pulse dynamics with realistic semiconductor parameters. Comprehensive material model, including TPG, carrier depletion, linear absorption, Kerr effect, plasma response of injected carriers, and the material dispersion were numerically simulated using the finite-difference time-domain method. Pulse compression down to a few optical cycles is theoretically predicted.

Negative Group Velocity: Is It a Negative Index Material or Fast Light?

When negative slop of the dispersion curve is encountered – the propagating light may be either ‘fast light’ or ‘backward propagating’. We show that the same photonic (plasmonic) system can support both these disjoint solutions.

Do Pulses in Negative Group Velocity Material Carry Negative Electromagnetic Energy

Negative dispersion can be exhibited in resonant materials with gain (or loss). The resulting causal pulses exhibiting

Nonlinear compression towards few-cycle pulses in two-photon semiconductor amplifiers

Ultra broadband nonlinear two-photon gain is proposed for pulse compression down to few optical cycles. Recent experimental report on two photon gain in semiconductor is exploited for analysis of pulse compression under realistic semiconductor parameters.

Semiconductor Two-Photon Laser: Ultra-Short Pulses and Wide Tuneability

Nonlinear two-photon gain in semiconductor is shown to compress pulses from hundreds of femto-seconds down to several optical cycles. Contentious-wave two-photon laser central wavelength can be adjusted over an ultra-wide spectrum by tuneable cavities.

Negative Electromagnetic Energy Interpretation of Negative Group Velocities in Metamaterials

Negative dispersion can be tailored in metamaterials with gain. Causal pulses in this medium are exhibiting

Semiconductor Devices Based on Two-Photon Emission

The first experimental observation of two-photon emission from semiconductors provides efficient compact room-temperature entangled photons sources for quantum information and spectroscopy, whereas the measured two-photon gain may lead to novel lasers emitting ultrashort optical pulses.