Trace of evanescent wave polarization by atomic vapor spectroscopy
M. Mosleh1, M. Ranjbaran2, S. M. Hamidi1,*
Various efforts have been made to determine the polarization state of evanescent waves in different structures. The present study shows the reliability of magneto-optical spectroscopy of D1 and D2 lines of rubidium metal and polarization-dependent transitions to investigate and trace the changes in the polarization state of evanescent fields during total internal reflection over different angles. For this purpose, we design and fabricate atomic- evanescent Rb vapor cells and examine the effect of polarization changes of evanescent waves, depending on the propagation direction of evanescent waves in anisotropic rubidium vapor media under different external magnetic field configurations theoretically and experimentally. The results confirm the dependency of allowed transitions on the magneto optical configuration as a tool to determine changes in the polarization of evanescent waves in more complicated wave states in anisotropic media.
Control over the interaction between photons with atoms promises quantum systems to serve as transmitters, receivers, and memory elements for information in a future quantum network.
How can information encoded in atoms or molecules be exchanged with single photons without corruption or loss? That is the key problem with which laser physicist Professor Gerhard Rempe, a director of the Max Planck Institute for Quantum Optics (MPQ; Garching, Germany), and his research group are concerned. In their efforts to solve it, they have designed optical resonators made up of pairs of mirrors placed in diametrically opposite positions in an ultrahigh-vacuum chamber (see Fig. 1). The volume enclosed by such an optical cavity is much less than a cubic millimeter, but the reflectivity of the mirrors is extremely high. Once inside a resonator, a photon will be reflected on the order of 100,000X before it is transmitted through one of the mirrors.
In their experiments, the researchers prepared a single atom, which has been cooled to a temperature of much less than 1 mK and place it in a resonator or at the center of two crossed resonators positioned orthogonally to each other (see Fig. 2). If a photon were to interact with the atom only once, the interaction would be very weak. However, because each photon makes the round trip between the cavity’s mirrors many times, the interaction is correspondingly amplified.
Rempe and his team have used this configuration as the basis for the construction of novel light sources that generate a stream of single-photon bits, and even quantum mechanically entangled photons, on demand.1 In addition, the setup can be used to transfer quantum information encoded in a single photon to the atom in a controlled manner.2 Furthermore, the group has shown that the presence or absence of a single photon can be nondestructively measured without altering the information encoded in the particle. That’s roughly analogous to checking whether there is a letter in the post office box without reading the content of that letter. However, it’s much more difficult to verify the arrival of a quantum letter without reading the quantum content.3 Experiments such as these are being performed in several of the group’s laboratories.
Rempe is one of the initiators in the field of cavity quantum electrodynamics. In 1987, he was the first person to demonstrate the repeated absorption and re-emission of a single microwave photon by a single atom. He went on to study how optical photons behaved when introduced into cavities formed by highly reflective mirrors. With this work, he became one of the pioneers of cavity quantum electrodynamics in the optical frequency range.
One-dimensional optomagnonic microcavities for selective excitation of perpendicular standing spin waves
V.A.Ozerov, D.A.Sylgacheva, M.A.Kozhaev, T. Mikhailova, V.N.Berzhansky, Mehri Hamidi, A.K. Zvezdin, V.I. Belotelov
Here we propose a method of the excitation of perpendicular standing spin waves (PSSWs) of different orders in an optomagnonic microcavity by ultrashort laser pulses. The microcavity is formed by a magnetic dielectric film surrounded by dielectric non-magnetic Bragg mirrors. Optical cavity modes in the magnetic layer provide concentration and strongly non-uniform distribution of the optical power over the layer thickness and therefore induce the effective field of the inverse Faraday effect also spatially non-uniform. It results in excitation of PSSWs. PSSWs whose wavevector is closest to the wavevector characterizing distribution of the inverse Faraday effect field are excited most efficiently. Consequently, a key advantage of this approach is a selectivity of the PSSW excitation which allows to launch PSSWs of required orders only. All-optical operation of the optomagnonic cavities opens new possibilities for their applications for quantum technologies.
Flat and Flexible 2D Plasmonic Crystal for Color Production
Neda Roostaei, S. M. Hamidi
Abstract— Recently, color production by using plasmonic structures has widely been studied. In this research, a flat and flexible two-dimensional Kapton-copper plasmonic crystal with very low thickness has been fabricated in a new and optimal way. Color production is performed using our proposed plasmonic structure and different colors are achieved by changing the incidence angle of light. Also, the plasmonic resonance response of the fabricated structure has been recorded at the incidence angle of 58 degrees. Advantages of our proposed structure are low cost, easy fabrication, and very small dimensions, and thus this research can be useful due to the increasing needs for the integration and miniaturizing of optical devices in modern nanophotonic systems.
The journal of Nano Letters published a paper entitled as “Magnesium Nanoparticle Plasmonics”
Nanoparticles of some metals (Cu/Ag/Au) sustain oscillations of their electron cloud called localized surface plasmon resonances (LSPRs). These resonances can occur at optical frequencies and be driven by light, generating enhanced electric fields and spectacular photon scattering. However, current plasmonic metals are rare, expensive, and have a limited resonant frequency range. Recently, much attention has been focused on earth-abundant Al, but Al nanoparticles cannot resonate in the IR. The earth-abundant Mg nanoparticles reported here surmount this limitation. A colloidal synthesis forms hexagonal nanoplates, reflecting Mg’s simple hexagonal lattice. The NPs form a thin self-limiting oxide layer that renders them stable suspended in 2-propanol solution for months and dry in air for at least two week. They sustain LSPRs observable in the far-field by optical scattering spectroscopy. Electron energy loss spectroscopy experiments and simulations reveal multiple size-dependent resonances with energies across the UV, visible, and IR. The symmetry of the modes and their interaction with the underlying substrate are studied using numerical methods. Colloidally synthesized Mg thus offers a route to inexpensive, stable nanoparticles with novel shapes and resonances spanning the entire UV-vis-NIR spectrum, making them a flexible addition to the nanoplasmonics toolbox.
In this days, the journal of arXiv preprint arXiv:2110 publishes a new paper entitled as “Magnetophotonics for sensing and magnetometry towards industrial applications”
Magnetic nanostructures sustaining different kinds of optical modes have been used for magnetometry and label-free ultrasensitive refractive index probing, where the main challenge is the realization of compact devices able to transfer this technology from research laboratories to smart industry. This Perspective discusses the state-of-the-art and emerging trends in realizing innovative sensors containing new architectures and materials exploiting the unique ability to actively manipulate their optical properties using an externally applied magnetic field. In addition to the well-established use of propagating and localized plasmonic fields, in the so-called magnetoplasmonics, we identified a new potential of the all-dielectric platforms for sensing to overcome losses inherent to metallic components. In describing recent advances, emphasis is placed on several feasible industrial applications, trying to give our vision on the future of this promising field of research merging optics, magnetism, and nanotechnology.
