Nanowerk May 10, 2019 The ability to detect small nano-particles and eventually single molecules remains a challenge. Current attempts focus on microring or microtoroid resonators which enhance the interaction between light and the molecule to be detected. The sensitivity of these devices, however, is limited by their fundamental physics. A team of researchers in the US (Michigan Technological University, University of Central Florida, Pennsylvania State University) propose a type of sensor based on the new notion of exceptional surfaces: surfaces that consist of exceptional points. However, the enhanced sensitivity of exceptional point-based sensors is very sensitive to unavoidable fabrication errors […]
Tag Archives: Sensors
Engineers develop novel techniques to trick object detection systems
Science Daily April 4, 2019 To understand and document vulnerabilities in deep and machine-learning algorithms, researchers at the Southwestern Research Institute have developed patterns when worn or mounted on a vehicle, cause the algorithms in the camera to either misclassify or mislocate objects, creating a vulnerability. Malicious parties could place these patterns near roadways, potentially creating chaos for vehicles equipped with object detectors. The researchers call these patterns ‘perception invariant’ adversarial examples because they don’t need to cover the entire object or be parallel to the camera to trick the algorithm. The algorithms can misclassify the object as long as […]
A direct current (DC) remote cloak to hide arbitrary objects
Phys.org March 27, 2019 An international team of researchers (China, Singapore) used a negative resistor network with active elements to achieve the remote function of the DC cloak. Based on this network, the cloak can remotely generate a hidden region without distorting the currents far from the cloaked region. The experimental results show that any object in the hidden region is invisible to a DC detector. The cloak does not require any knowledge of the hidden object. The cloaking device may find potential applications in medical or geologic research…read more. Open Access TECHNICAL ARTICLE
Waterproof graphene electronic circuits
Science Daily January 30, 2019 Water molecules change the electrical resistance of this carbon material, which introduces a false signal into the sensor. An international team of researchers (Sweden, Germany) discovered that when this two-dimensional material is integrated with the metal of a circuit, contact resistance is not impaired by humidity. They used graphene together with gold metallization and silica substrates in transmission line model test structures, as well as computer simulations to demonstrate their discovery. As part of the European CO2-DETECT project, they are applying this new approach to create the first prototypes of graphene-based sensors to measure carbon […]
New T-wave detector uses waves of the electronic sea in graphene
Nanowerk December 21, 2018 It has proven challenging to implement plasmonic devices operating at terahertz frequencies. An international team of researchers (UK, Russia, Japan) has demonstrated plasmon-assisted resonant detection of terahertz radiation by antenna-coupled graphene transistors that act as both plasmonic Fabry-Perot cavities and rectifying elements. By varying the plasmon velocity using gate voltage, they could tune the detectors between multiple resonant modes. The devices offer a convenient tool for further plasmonic research and promise a viable route for various photonic applications… read more. Open Access TECHNICAL ARTICLE
New technique to make objects invisible proposed
Eurekalert November 26, 2018 Most of the techniques for cloaking harness the extraordinary properties of certain materials to make light circumvent the object to be made invisible. An international team of researchers (Spain, Italy) has developed a technique using the electromagnetic properties of specific materials which can make certain objects invisible when they are introduced as fillers. This plasmonic cloaking makes the object and the filler jointly invisible. The method makes it possible to achieve invisibility from the interior of an object without using any external device and allows the object to interact with its environment without being hampered by […]
Physicists design new antenna for next-generation super-sensitive magnetometers
Phys.org November 6, 2018 Ensembles of nitrogen-vacancy color centers in diamond hold promise for ultra-precise magnetometery, competing with superconducting quantum interference device detectors. By utilizing the advantages of dielectric materials, such as very low losses for electromagnetic field, with the potential for creating high-quality factor resonators with strong concentration of the field within it, researchers in Russia implemented a dielectric resonator antenna for coherent manipulation of a large ensemble of nitrogen-vacancy centers in diamond. Research enables use of large volume low nitrogen-vacancy concentration diamond plates in modern nitrogen-vacancy magnetometers thus improving sensitivity via larger coherence time and higher optical detected […]
Honing quantum sensing
MIT News September 25, 2018 Extreme sensitivity of quantum sensors to their surrounding environment creates the vexing problem of environmental noise in quantum sensor systems. A team of researchers in the US (MIT, Yale University) has developed an approach that is complementary to existing Dynamical decoupling and established error-corrected quantum sensing (ECQS) methods. This approach allows frequency-independent filtering, because it exploits spatial rather than temporal noise correlations. The new ECQS scheme makes use of noise correlations at different positions in a quantum sensor. In this way, the new approach can tell signal from noise even in the common case where […]
Scientists reduced the weight of optics for satellite observation by 100 times
Eurekalert August 8, 2018 Researchers in Russia have created an optical element for reconstructing images taken with diffractive optics on a satellite. It weighs only 5 grams and replaces a complex and massive system of lenses and mirrors similar to the one that is used in telephoto lenses with a focal length of 300 mm and a weight of 500 grams. They proposed to compensate for distortions with the use of digital processing. The computational reconstruction developed by them includes colour correction of the image and elimination of chromatic blurring using convolutional neural networks (CNN). The compact system is particularly […]
A single photon detection system for the spectrum range up to 2300 nm
Arxiv July 11. 2018 An international team of researchers (Russia, Poland) has demonstrated niobium nitride based superconducting single-photon detectors are sensitive in the spectral range 457 nm – 2300 nm. The system performance was tested in a real-life experiment with correlated photons generated by means of spontaneous parametric down conversion, where one of photon was in the visible range and the other was in the infrared range. They measured a signal to noise ratio as high as 4×104 in their detection setting. A photon detection efficiency as high as 64 % at 1550 nm and 15 % at 2300 nm […]