Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userNonspreading Light Pulses in Photonic Crystals
101
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
We investigate propagation of light pulses in photonic crystals in the vicinity of the zero-diffraction point. We show that Gaussian pulses due to nonzero width of their spectrum spread weakly in space and time during the propagation. We also find the family of nonspreading pulses, propagating invariantly in the vicinity of the zero diffraction point of photonic crystals.
rate research
Read More
The integration of nanophotonics and atomic physics has been a long-sought goal that would open new frontiers for optical physics. Here, we report the development of the first integrated optical circuit with a photonic crystal capable of both localizing and interfacing atoms with guided photons in the device. By aligning the optical bands of a photonic crystal waveguide (PCW) with selected atomic transitions, our platform provides new opportunities for novel quantum transport and many-body phenomena by way of photon-mediated atomic interactions along the PCW. From reflection spectra measured with average atom number N = 1.1$pm$0.4, we infer that atoms are localized within the PCW by Casimir-Polder and optical dipole forces. The fraction of single-atom radiative decay into the PCW is $Gamma_{rm 1D}/Gamma$ = 0.32$pm$0.08, where $Gamma_{1D}$ is the rate of emission into the guided mode and $Gamma$ is the decay rate into all other channels. $Gamma_{rm 1D}/Gamma$ is quoted without enhancement due to an external cavity and is unprecedented in all current atom-photon interfaces.
We describe a smooth transition from (fully ordered) photonic crystal to (fully disordered) photonic glass that enables us to make an accurate measurement of the scattering mean free path in nanostructured media and, in turn, establishes the dominant role of the density of states. We have found one order of magnitude chromatic variation in the scattering mean free path in photonic crystals for just $sim 3%$ shift around the band-gap ($sim 27$ nm in wavelength).
We show that it is possible to confine light in a volume of order 10^-3 cubic wavelengths using only dielectric material. Low-index (air) cavities are simulated in high index rod-connected diamond (RCD) photonic crystals. These cavities show long storage times (Q-factors >10^6) even at the lowest volumes. Fabrication of such structures could open up a new field of photon level interactions.
We propose an efficient method for spatial filtering of light beams by propagating them through 2D (also 3D) longitudinally chirped photonic crystals, i.e. through the photonic structures with fixed transverse lattice period and with the longitudinal lattice period varying along the direction of the beam propagation. We prove the proposed idea by numerically solving the paraxial propagation equation in refraction index-modulated media, and we evaluate the efficiency of the process by plane-wave-expansion analysis. The technique can be applied to filter (to clean) the packages of atomic waves (Bose condensates), as well improve the directionality of acoustic and mechanical waves.
Slow-light enhanced optical detection in liquid-infiltrated photonic crystals is theoretically studied. Using a scattering-matrix approach and the Wigner-Smith delay time concept, we show that optical absorbance benefits both from slow-light phenomena as well as a high filling factor of the energy residing in the liquid. Utilizing strongly dispersive photonic crystal structures, we numerically demonstrate how liquid-infiltrated photonic crystals facilitate enhanced light-matter interactions, by potentially up to an order of magnitude. The proposed concept provides strong opportunities for improving existing miniaturized absorbance cells for optical detection in lab-on-a-chip systems.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
