Research Lines

Quantum Optics:
The foundation of modern Optics has provided a challenge to our perception since the introduction of quantum theory of light. The development of technology has moved us closer to limits set by nature rather than by our skills. This means that understanding the foundation of quantum optics is becoming more important. In recent years, there was a lot of attention to the field of quantum optics and the related phenomena. We are interested in developing the quantum information and communication as well as quantum coherence and interference.

A. Quantum Coherence and Interference (QCI)

Atomic coherence and interference are the basic mechanism for the new interesting phenomena such as electromagnetically induced transparency (EIT), coherent population trapping (CPT), lasing without inversion (LWI). Quenching the spontaneous emission, reduction of absorption and controlling the group velocity of a light pulse in a dispersive medium can be realized by the quantum coherence and interference. We are interested in the quantum coherence phenomena and strongly study the response of an atomic system to the applied fields. We are involved in the theoretical investigation of:

1. Controlling the spontaneous emission

2. Transient and steady state behavior of the absorption and the dispersion in a dispersive media

3. Controlling the light propagation subluminal to superluminal

4. Atom localization via absorption

B. Quantum Information Processing and Communication (QIPC)

The paper of Einstein, Podolsky, and Rosen led Schrodinger to introduce the term entanglement for a superposition of states of subsystems that may be far apart. Entanglement is one of the most fascinating and puzzling aspects of quantum Physics. The main resource in quantum information technology is unquestionably quantum entanglement. It has been used for teleportation, quantum cryptograph, and it is the main ingredient of quantum parallel computation. We are carrying out theoretical analyses to study this problem.

Cavity Soliton (CS)
Cavity solitons (CSs) are stationary bright/dark 1-peak localized structures over a homogeneous background in the section of broad radiation beams. The possibility of switching them on/off, controlling their location and their motion makes them interesting as pixels for reconfigurable arrays or all-optical processing units.

Most interesting the practical viewpoint, for miniaturization purposes, is the case in which the active medium is a semiconductor: the standard configuration on which we will focus our attention is that of an optical cavity containing a semiconductor medium and driven by a stationary holding beam (HB); both the material sample and the holding beam have a large section. In our group, we intend to introduce a decisive advancement in the understanding and the control of the behavior of Cavity Solitons in Semiconductor microresonators. Very recent experiments have shown that thermal effects play a dominant role in these phenomena. We used models that include these effects and defined the appropriate procedures to control the behavior of Cavity Solitons in presence of such effects, as it is necessary for the prospective applications of these phenomena.

We are involved in the theoretical investigation of:

1) Motion of Cavity Solitons induced by the presence of phase/amplitude gradients in the holding beam.

2) Spontaneous motion of CSs induced by the slow thermal effects.

3) Controlling of cavity solitons spontaneous motion.

4) Cavity Soliton above laser threshold.

Photonic Band-Gap Crystals (PBC)
Photonic Crystals are wavelength scale, periodic, dielectric microstructures. Their periodic patterning creates photonic band gaps which forbid the propagation of light through the structure. The periodicity couples forwards and backwards waves inside the Photonic Crystal (PhC), causing a net cancellation of the optical field. PhCs therefore insulate photons in a manner similar to which electrons are insulated in a semiconductor crystal. We are also interested in the Coherent phenomena in PhCs.

Controlling the spontaneous emission in PhCs
Steady state and transient properties of absorption and dispersion in PhCs
Controlling the light propagation subluminal to superluminal in PhCs