Related papers: Pushing the limits of negative group velocity
We propose a scheme to couple short single photon pulses to superconducting qubits. An optical photon is first absorbed into an inhomogeneously broadened rare-earth doped crystal using controlled reversible inhomogeneous broadening. The…
In this letter we experimentally demonstrate that the signal velocity, defined as the earliest time when a signal is detected above the realistic noise floor, may be altered by a region of anomalous dispersion. We encode information in the…
We report experimental investigationd of optical pulse group velocity reduction and probe pulse regeneration using a Raman scheme. The new scheme which does not rely on the on-one-photon resonance electromagnetically induced transparency…
Ultrafast pulses, particularly those with durations under 100 femtoseconds, are crucial in achieving unprecedented precision and control in light-matter interactions. However, conventional on-chip photonic platforms are not inherently…
We present a simple electronic circuit which provides negative group delays for band-limited, base-band pulses. It is shown that large time advancement comparable to the pulse width can be achieved with appropriate cascading of…
In this study, we introduce a design concept that leverages pulse width variation to enable a reconfigurable intelligent surface (RIS) and to autonomously switch reflection properties between two angles without any active control system.…
We show that arrival times for electromagnetic pulses measured through the rate of absorption in an ideal impedance matched detector are equivalent to the arrival times using the average flow of optical energy as proposed by Peatross {\it…
The ability to control the speed and polarisation of light pulses will allow for faster data flow in optical networks of the future. Optical delay and switching have been achieved using slow-light techniques in various media, including…
We experimentally study the group time delay for a light pulse propagating through hot Rb vapor in the presence of a strong coupling field in a $\Lambda$ configuration. We demonstrate that the ultra-slow pulse propagation is transformed…
Transparent materials do not absorb light but have profound influence on the phase evolution of transmitted radiation. One consequence is chromatic dispersion, i.e., light of different frequencies travels at different velocities, causing…
Recently, we have shown that the wave-front of short pulses can be accurately and efficiently reversed by use of simple one-dimensional zero-gap photonic crystals. In this Article, we describe the analytical approach in detail, and discuss…
Anomalous dispersion cannot occur in a transparent passive medium where electromagnetic radiation is being absorbed at all frequencies, as pointed out by Landau and Lifshitz. Here we show, both theoretically and experimentally, that…
The sub-luminal phase velocity of electromagnetic waves in free space is generally unobtainable, being closely linked to forbidden faster than light group velocities. The requirement of effective sub-luminal phase-velocity in laser-driven…
This paper reports the observation of ultra-superluminal pulse propagation in GaAs/AlGaAs multiple contact heterostuctures in a superradiant emission regime, and shows definitively that it is a different class of emission from conventional…
Group delay for a reflected light pulse from a weakly absorbing dielectric slab is theoretically investigated, and large negative group delay is found for weak absorption near a resonance of the slab ($Re(kd)=m\pi$). The group delays for…
Metasurfaces composed of subwavelength unit cells usually require a large number of unit cells which leads to complicated design and optimization. Aggressive discretization in a metasurface can significantly reduce the number of unit cells…
We demonstrate experimentally and theoretically a controllable way of shifting the frequency of an optical pulse by using a combination of spectral hole burning, slow light effect, and linear Stark effect in a rare-earth-ion doped crystal.…
We have characterized a novel photon-echo pulse sequence for a double-$\Lambda$ type energy level system where the input and rephasing transitions are different to the applied $\pi$-pulses. We show that despite having imperfect $\pi$-pulses…
Nondiffracting pulsed beams are well studied nowadays and can be as short as a few femtoseconds. The nondiffracting pulsed beams not only resist diffraction but also propagate without changes due to the dispersion of a linear dispersive…
We have observed the propagation of an approximately 35 ns long light pulse with a negative group velocity through a laser-cooled 85Rb atomic medium. The anomalous dispersion results from linear atom-light interaction, and is unrelated to…