Nanowerk July 16, 2018 Current technology for polarization beam splitters is limited to extinction ratio of around 25 decibels which is high enough to affect high-speed data transmission. Researchers in Singapore conceptualized design for a three-waveguide device and verified its feasibility on computer simulation. They confirmed its vastly improved extinction ratio of 40 decibel, representing a further 30-fold reduction in polarization crosstalk. The research is a breakthrough in improving high-performance data transmission systems, as well as applications in quantum computing… read more. TECHNICAL ARTICLE
Category Archives: Communications technology
A silicon-nanoparticle photonic waveguide
Nanowerk July 16, 2018 To efficiently transport light on small scales, researchers in Singapore have developed a more efficient method that involves a string of cylindrical silicon nanoparticles. The first nanoparticle is excited using light and then measured the light that reaches another nanoparticle further down the line. They found the fall in the light intensity to be low. The nanoparticles are not in direct contact with each other. Instead, light is transferred to the next particle through magnetic-field resonances. Although each particle is a resonant scatterer when they are lined up they work as a single waveguide without leaking […]
100 times faster broadband is coming: 5G passes first test
Science Daily July 6, 2018 With phase one of 5G global industry standards just being completed which focuses on 5G enhanced mobile broadband, research is now moving to address 5G technology to support ultra-reliable and ultra-low-latency connectivity for “vertical industries”. Researchers in the UK focus on the new frontiers of 5G, as well as investigating future deployment by operators, including indoor coverage and spectrum coexistence in newly assigned 5G frequencies in 3.5 Ghz and lower mm-wave bands. They have successfully completed the measurements of the indoor coverage of 5G signals. 5G is expected to be commercially available as early as […]
Fiber-optic transmission of 4,000 km made possible by ultra-low-noise optical amplifiers
Eurekalert July 5, 2018 The capacity and reach of long-haul fiber optical communication systems is limited by in-line amplifier noise and fiber nonlinearities. An international team of researchers (Sweden, Estonia) has demonstrated a multi-channel-compatible and modulation-format-independent long-haul transmission link with in-line phase-sensitive amplifiers with an improvement of 5.6 times at optimal launch powers with the phase-sensitively amplified link operating at a total accumulated nonlinear phase shift of 6.2 rad. The link transmits two data-carrying waves, thus occupying twice the bandwidth and propagating twice the total power compared to the phase-insensitively amplified link… read more. Open Access TECHNICAL ARTICLE
Multiple lasers could be replaced by a single microcomb
Science Daily June 12, 2018 An international team of researchers (Sweden USA – Purdue University) reports the first coherent-transmission experiments using 64-quadrature amplitude modulation encoded onto the frequency lines of a dark-pulse comb. The high conversion efficiency of the comb enables transmitted optical signal-to-noise ratios above 33 dB, while maintaining a laser pump power level compatible with state-of-the-art hybrid silicon lasers. The research helps to better understand the formation of dark pulses in microresonators and their potential use in optical communications. The research could lead to faster and more power-efficient optical communication links in the future… read more. Open Access TECHNICAL […]
Antiferromagnetic materials allow for processing at terahertz speeds
Science Daily May 24, 2018 An international team of researchers (Czech Republic, Germany, UK, Switzerland, USA – Texas A&M, Saudi Arabia) has demonstrated at room temperature that the speed of reversible electrical writing in a memory device can be scaled up to terahertz using an antiferromagnet. A current-induced spin-torque mechanism is responsible for the switching in our memory devices throughout the 12-order-of-magnitude range of writing speeds from hertz to terahertz. The work opens the path toward the development of memory-logic technology reaching the terahertz band… read more. Open Access TECHNICAL ARTICLE 1 , TECHNICAL ARTICLE 2
Towards Quantum Communication from Global Navigation Satellite System
Arxiv April 13, 2018 High-orbit satellites pose a great technological challenge due to the high diffraction losses of the optical channel, and the experimental investigation of quantum channels is still lacking. Researchers in Italy report on the exchange of single photons from Global Navigation Satellite System (GNSS) at a slant distance of 20,000 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 estimated the requirements needed for an active source on a satellite, aiming towards quantum communication from GNSS with state-of-the-art […]
Demonstration of world record: 159 Tb/s transmission over 1,045 km with 3-mode fiber
Eurekalert April 13, 2018 Researchers in Japan have developed a 3-mode optical fiber, capable of wide-band wavelength multiplexing transmission with standard outer diameter (0.125 mm) that can be cabled with existing equipment. They have demonstrated a transmission experiment over 1045 km with a data-rate of 159 Tb/s. Converting the results to the product of data-rate and distance results in 166 Pb/s×km. This is the world record in a standard outer diameter few-mode optical fiber and the largest data-rate over 1000 km for any kind of standard-diameter fiber… read more.
New device modulates light and amplifies tiny signals
Phys.org April 9, 2018 Researchers at NIST have created a plasmomechanical oscillator (PMO) that tightly couples plasmons to the mechanical vibrations of the much larger device in which it is embedded. The device consists of a gold nanoparticle, about 100 nanometers in diameter, embedded in a tiny cantilever made of silicon nitride. An air gap lies sandwiched between these components and an underlying gold plate; the width of the gap is controlled by an electrostatic actuator and bends toward the plate when a voltage is applied. The nanoparticle acts as a single plasmonic structure that has a natural frequency that […]
Thin engineered material perfectly redirects and reflects sound
Science Daily April 10, 2018 Using 3-D printers, an international team of researchers (USA – Duke University, Finland) fabricated a metamaterial made of a series of rows of hollow columns with a narrow opening cut down the middle of one side. The width of the channels between each row of columns and the size of the cavity inside each individual column controls how the sound is manipulated. The program is fed boundary conditions needed to dictate the outgoing and reflected waves’ behavior. They demonstrated redirecting a sound wave coming straight at the metamaterial to a sharp 60-degree outgoing angle with […]