Next Big Future December 24, 2018 Researchers in Italy have reported on the first experimental exchange of single photons from Global Navigation Satellite System at a slant distance of 20000 kilometers, by exploiting the retroreflector array mounted on GLONASS satellites. They observed the predicted temporal spread of the reflected pulses due to the geometrical shape of array. They provide estimated the requirements needed for an active source on a satellite, aiming towards quantum communication from GNSS with state-of-the-art technology… read more. Open Access TECHNICAL ARTICLE
Tag Archives: Communications technology
Discovery of topological LC circuits transporting EM waves without backscattering
Eurekalert December 26, 2018 An international team of researchers (China, Japan) demonstrates that topological propagation of electromagnetic waves can be induced using conventional materials in a simple structure. Because topological electromagnetic wave propagation is immune to backscatter even when pathways turn sharply, designs of compact electromagnetic circuits become possible, leading to miniaturization and high integration of electronics devices. In addition, the direction of vortex and the vorticity associated with topological electromagnetic modes may be used as data carriers in high-density information communications. All these features may contribute to the development of advanced information society represented by IoT and autonomous vehicles… […]
Scientists design new material to harness power of light
Phys.org December 17, 2018 An international team of researchers (USA – MIT, University of Hartford, UK. France) found that several materials with poor nonlinear characteristics can be combined, resulting in a new metamaterial that can be “tuned” to change the color of light. The enhancement comes from the way the metamaterial reshapes the flow of photons. They describe the underlying physics, compare its predictions to the experimental results, and analyze the limits of its applicability. The work opens a new direction in controlling the nonlinear response of materials and may find applications in on-chip optical circuits, drastically improving on-chip communications…read […]
Shape-shifting origami could help antenna systems adapt on the fly
Tech Explore December 10, 2018 Researchers at the Georgia Institute of Technology focused on Miura-Ori, which has the ability to expand and contract like an accordion, to create radio frequency filters that have adjustable dimensions, enabling the devices to change which signals they block throughout a large range of frequencies. They used a special printer that scored paper to allow a sheet to be folded in the origami pattern. An inkjet-type printer was then used to apply lines of silver ink across those perforations, forming the dipole elements that gave the object its radio frequency filtering ability. They found that […]
Changing color of light using a spatiotemporal boundary
Phys.org November 29, 2018 Effective temporal control of the medium is critical for frequency conversion. Researchers in South Korea designed a metasurface for the sudden merging of two distinct metallic meta-atoms into a single one upon ultrafast optical excitation. Sudden merging creates a spectrally designed temporal boundary on the metasurface by which the frequency conversion can be achieved and engineered. The technique provides a spatiotemporal boundary as a platform for freely designing and changing the spectral properties of the medium. Since frequency conversion can be observed even in weak light, this technique could be particularly useful in communication technology…read more. […]
QuTech researchers put forward a roadmap for quantum internet development
Delft University of Technology (the Netherlands) October 18, 2018 Researchers in the Netherlands describe six phases, starting with simple networks of qubits that could already enable secure quantum communications – a phase that could be reality in the near future. The development ends with networks of fully quantum-connected quantum computers. In each phase, new applications become available such as extremely accurate clock synchronization or integrating different telescopes on Earth in one virtual ‘supertelescope’. This work creates a common language that unites the highly interdisciplinary field of quantum networking towards achieving the dream of a world-wide quantum internet… read more. TECHNICAL […]
Bursting the clouds for better communication
Phys.org October 18, 2018 Researchers in Switzerland have developed a laser that heats the air over 1,500 degrees Celsius and produces a shock wave to expel the suspended water droplets sideways. This creates a hole a few centimetres wide over the entire thickness of the cloud. The laser beam should be kept on the cloud and the laser that contains the information should be sent at the same time. It then slips into the hole through the cloud and allows the data to be transferred. This “laser cleaner” is currently being tested on artificial clouds that are 50 cm thick […]
Security vulnerabilities in terahertz data links
Science Alert October 15, 2018 Unlike microwaves, which propagate in wide-angle broadcasts, terahertz waves travel in narrow, very directional beams with a cone angle of less than 2 degrees. A team of researchers in the US (Brown University, Rice University, SUNY Buffalo) set up a direct line-of-site terahertz data link between a transmitter and receiver and experimented with devices capable of intercepting signal. They were able show several strategies that could steal signal without being detected by using a flat piece of metal that could redirect a portion of the beam to a secondary receiver operated by an attacker…read more. […]
Measurement-device-independent quantum communication without encryption
Phys.org October 11, 2018 The key problem of practical quantum secure direct communication (QSDC) is that apparatuses used in practical quantum communication systems have some defects, and these imperfections, especially defects in the measurement devices, can lead to leakage of information and affect the security of practical QSDC. Researchers in China proposed a measurement-and-device-independent quantum secure direct communication protocol using Einstein-Podolsky-Rosen pairs. This protocol eliminates all loopholes related to measurement devices, which solves a key obstacle in practical quantum secure direct communication. The protocol has also an extended communication distance, and a high communication capacity…read more. TECHNICAL ARTICLE
Quantum technologies can be applied on a standard telecommunications network
Phys.org October 4, 2018 Researchers in Spain have developed a quantum cryptography network integrated in a commercial optical network through technologies based on software defined networking allowing for the implementation of quantum and classical network services in a flexible, dynamic and scalable manner. The technology has been developed on an existing infrastructure using standard communications systems and allows switching between links connecting points that may be up to 60 kilometers apart. Twenty channels can share the same fiber in the same optical band that uses the quantum channel, allowing the simultaneous transmission of quantum signals with more than two terabytes […]