Spatiotemporal Multiplexed Rydberg Receiver

Rydberg states of alkali atoms, where the outer valence electron is excited to high principal quantum numbers, have large electric dipole moments allowing them to be used as sensitive, wideband, electric field sensors. These sensors use electromagnetically induced transparency (EIT) to measure incident electric fields. The characteristic timescale necessary to establish EIT determines the effective speed at which the atoms respond to time-varying RF radiation. Previous studies have predicted that this EIT relaxation rate causes a performance roll-off in EIT-based sensors beginning at a less than 10 MHz RF data symbol rate. Here, we propose an architecture for increasing the response speed of Rydberg sensors to greater than 100 MHz, through spatio-temporal multiplexing (STM) of the probe laser. We present experimental results validating the architecture's temporal multiplexing component using a pulsed laser. We benchmark a numerical model of the sensor to this experimental data and use the model to predict the STM sensor's performance as an RF communications receiver. For an on-off keyed (OOK) waveform, we use the numerical model to predict bit-error-ratios (BERs) as a function of RF power and data rates demonstrating feasibility of error free communications up to 100 Mbps with an STM Rydberg sensor.Comment: 7 pages, 7 figure

Spread Photon Transceiver for Quantum Secure Communications

Quantum communication protocols provide capabilities for private information exchange despite adversarial access to quantum resources. However, existing protocols can be limited by speed, and considerations around their practical implementation. We report on a novel quantum communications protocol, called the spread photon transceiver, which operates on the physical layer of a communications link with a pair of matched receivers, to achieve quantum security. The sensitivity of the matched receiver architecture to experimental error is evaluated. A security analysis of the protocol is conducted, evaluating the private information rate achievable between the intended sender and receiver, assuming a quantum-powerful adversary, with receiver losses reflective of scenarios which may be encountered in a military field environment.Immediate accessThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Polymer Photonic Crystal Structures

We report on on all-polymer photonic crystals having different dimensionality. One-dimensional photonic crystals i.e. Distributed Bragg Reflectors (DBR) made of cellulose acetate and ZnO-polystyrene (PS) nanocomposites or Poly(p-phenyleneoxide) (PPO) have been prepared. When such structures are exposed to solvent vapors, remarkable photonic band gap spectral shifts can be observed due to free-volume effects (in the case of ZnO:PS nanocomposite) or to the peculiar crystallization properties of PPO.[1, 2] Such findings indicate that polymer DBR can be successfully used as low cost gas sensors. A variation of the 1D DBR structure is provided by the microcavity where a layer breaking the periodicity is inserted in the middle of the DBR structure.[3] When such structural defect is made by photochromic poly[[4-pentyloxy-3\u2019-methyl-4\u2019(6-methacryloxyhexyloxy)]azobenzene], strong photomodulation effects can be observed upon induced photoisomerization. Such microcavities show reversible spectral shifts larger than those so far reported in inorganic systems [4] indicating the quality of both the polymer mirrors and photochromic azo derivative. Monodisperse polymer and silica microspheres with an engineered structure (surface chemistry, core-shell structure, insertion of fluorophore and/or metal nanoparticles) are used to prepare compact monolayers of spheres and artificial opals. The 2D structures, whose optical response is tuned by sphere diameter are used both as template for grazing evaporation of half-moon shaped plasmonic nanostructures as well as for their peculiar light diffraction properties. Artificial opals (3D photonic crystals) made with core-shell microspheres containing fluorescent molecules allows to observe directional enhanced light emission.[5] [1] P. Lova, et al., Phys. Status Solidi C 2014, DOI: 10.1002/pssc.201400209. [2] C. Daniel, et al., Chem. Mater. 2011, 23, 3195. [3] G. Canazza, et al., Laser Phys. Lett. 2014, 11, 035804. [4] R. Piron, et al., Appl. Phys. Lett. 2000, 77, 2461. [5] K. Sparnacci, et al., J. Nanomater. 2012, 2012, 98054