Science Daily February 15, 2018 Researchers at the University of Maryland created a photonic chip that both generates single photons and steers them around. In the new chip, they etched out thousands of triangular holes in an array that resembled a bee’s honeycomb. Along the center of the device they shifted the spacing of the holes, which opens a different kind of travel lane for the light. The team tested the capabilities of the chip by first changing a quantum emitter from its lowest energy state to one of its two higher energy states. When they used photons from the […]
Category Archives: Communications technology
Palmreaders? Japan team builds second skin message display
Physorg February 18, 2018 Researchers in Japan have invented a band-aid-like stretchable device which is one millimetre thick and can monitor important health data as well as send and receive messages, including emojis. The display consists of a 16-by-24 array of micro LEDs and stretchable wiring mounted on a rubber sheet and a lightweight sensor composed of a breathable “nanomesh” electrode, and a wireless communication module. It can be placed on the human body for a week without causing skin inflammation. It has medical applications and wearable displays… read more.
Physicists create new form of light
MIT News February 15, 2018 A team of researchers in the US (MIT, Harvard University, Princeton University, NITS, University of Chicago) has observed groups of three photons interacting and, in effect, sticking together to form a completely new kind of photonic matter. In controlled experiments, the researchers found that when they shone a very weak laser beam through a dense cloud of ultracold rubidium atoms, rather than exiting the cloud as single, randomly spaced photons, the photons bound together in pairs or triplets, suggesting some kind of interaction — in this case, attraction — taking place among them. According to […]
Taking terahertz data links around the bend
Science Daily February 6, 2018 Unlike microwaves, terahertz waves are entirely blocked by most solid objects. The assumption has been that it’s not possible to bounce a terahertz beam around — say, off a wall or two — to find a clear path around an object. A team of researchers in the US (Brown University, New Jersey Institute of Technology) bounced terahertz waves at four different frequencies off a variety of objects and showed that acceptable bit-error-rates were achievable with modest increases in signal power… read more. Open Access TECHNICAL ARTICLE
A Beam-Steering Antenna for 5G Mobile Phones
IEEE Spectrum January 28, 2018 An international team of researchers (China, Taiwan) has developed a 28 GHz beam-steering antenna array that can be integrated into the metallic casing of 5G mobile phones. The array antenna has 16 cavity-backed slot antenna elements that are implemented via the metallic back casing of the mobile device, in which two eight-element phased arrays are built on the left- and right-side edges of the mobile device. Each eight-element phased array can yield beam steering at broadside and gain of >15 dBi can be achieved at boresight. The measured 10 dB return loss bandwidth of the […]
DARPA Seeks to Improve Military Communications with Digital Phased-Arrays at Millimeter Wave
DARPA News January 24, 2018 DARPA is launching the Millimeter-Wave Digital Arrays (MIDAS) program which aims to develop element-level digital phased-array technology that will enable next generation DoD millimeter wave systems. Research efforts will focus on reducing the size and power of digital millimeter wave transceivers, enabling phased-array technology for mobile platforms and elevating mobile communications to the less crowded millimeter wave frequencies. MIDAS is focused on two key technical areas. The first is the development of the silicon chips to form the core transceiver for the array tile. The second area is focused on the development of wide-band antennas, […]
Scientists realize strong indirect coupling in distant graphene-based nanomechanical resonators
Nanowerk January 28, 2018 The main problem using nanomechanical resonators as information carriers is the realization of tunable phonon interaction at long distance. An international team of researchers (China, USA) reports the experimental observation of strong indirect coupling between separated mechanical resonators in a graphene-based electromechanical system. The coupling is mediated by a far-off-resonant phonon cavity through virtual excitations via a Raman-like process. By controlling the resonant frequency of the phonon cavity, the indirect coupling can be tuned in a wide range. The results may lead to the development of gate-controlled all-mechanical devices and open the possibility of long-distance quantum […]
Researchers use sound waves to advance optical communication
Physorg January 22, 2018 There are several problems with using magnetically responsive materials to achieve the one-way flow of light in a photonic chip. Researchers at University of Illinois at Urbana-Champaign, produced a non-reciprocal modulator by means of indirect interband scattering. They broke the time-reversal symmetry using a two-dimensional acoustic pump that simultaneously provides a non-zero overlap integral for light–sound interaction and satisfies the necessary phase-matching. Their device is 200 by 100 microns in size, made of aluminum nitride. Sound waves, produced using tiny electrodes written directly onto the aluminum nitride, compel light within the device to travel only in […]
Scientists create high-speed coding system
Physorg January 23, 2018 Researchers in Russia have proposed and demonstrated a scheme for optical encoding of information based on the formation of wave fronts that works with spatially incoherent illumination. They used a liquid-crystal phase light modulator as the encoding element, where pre-synthesized diffraction optical elements are displayed. The camera’s image sensor detects the optical convolution of the image that is produced by the amplitude modulator with the pulse response of the diffractive element, derived on the phase modulator. They successfully encoded and decoded the images of QR codes with a size up to 129×129 elements. The percentage of […]
Pulses of light to encrypt data and protect security of cryptocurrencies
Physorg January 11, 2018 An international team of researchers (USA – University of Southern California, Mexico) report a new strategy to fabricate near-infrared frequency combs based on combining high-Q microcavities with monomolecular layers of highly nonlinear small molecules. The functionalized microcavities demonstrate high-efficiency parametric oscillation in the near-IR and generate primary frequency combs with 0.88-mW thresholds, improving optical parametric oscillation generation over nonfunctionalized devices by three orders of magnitude. This organic-inorganic approach enables otherwise unattainable performance and will inspire the next generation of integrated photonic device platforms… read more. Open Access TECHNICAL ARTICLE