Science Daily August 27, 2019 Researchers at UCLA have made systematic improvements to their earlier work on diffractive optical neural networks, based on a differential measurement technique that mitigates the strict nonnegativity constraint of light intensity. In this differential detection scheme, each class is assigned to a separate pair of detectors, behind a diffractive optical network, and the class inference is made by maximizing the normalized signal difference between the photodetector pairs. Using this differential detection scheme, they numerically achieved blind testing accuracies of 98.54%, 90.54%, and 48.51% for MNIST, Fashion-MNIST, and grayscale CIFAR-10 datasets, respectively. They reduced the crosstalk […]
Tag Archives: Light-matter interaction
Coupled exploration of light and matter
Science Daily July 15, 2019 Polaritonics is based on the strong coupling of photons to atomic or electronic excitations in an optical resonator. An international team of researchers (Switzerland, France) describes experiments which indicate that, in addition to strong correlations in the electronic ground state, exciton–electron interactions leading to the formation of polaron-polaritons have a key role in enhancing the nonlinear optical response of the system. The research opened fresh perspectives for exploring both ingredients of the polariton, novel functionalities for photonic devices and fundamental insight into exotic states of matter…read more. TECHNICAL ARTICLE
Better microring sensors for optical applications
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 […]
Bowtie-funnel combo best for conducting light; team found answer in simple equation
Phys.org August 24, 2018 An international team of researchers (USA – Vanderbilt University, IBM, France) developed a structure that’s part bowtie, part funnel that concentrates light powerfully and nearly indefinitely, as measured by a scanning near field optical microscope. Only 12 nanometers connect the points of the bowtie. What is special about their research is that the use of the bowtie shape concentrates the light so that a small amount of input light becomes highly amplified in a small region. We can potentially use that for low power manipulation of information on computer chips. Their approach opens the door to […]