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 […]
Tag Archives: Optics
Speed of light drops to zero at ‘exceptional points’
Phys org January 31, 2018 An international team of researchers (Israel, Brazil) has theoretically demonstrated a new way to bring light to a standstill at “exceptional points”. Exceptional points can be created in waveguides by varying the gain/loss parameters so that two light modes coalesce. The loss of light can be fixed by using waveguides with parity-time symmetry, as this symmetry ensures that the gain and loss are always balanced. To release the stopped light and accelerate it back up to normal speed, the gain/loss parameters can be reversed. Unlike most other methods that are used to stop light, the […]
Carbon nanotube as ultrafast emitter with narrow energy spread at optical frequency
Nanowerk January 2, 2018 An international team of researchers (China, Finland) used carbon nanotubes to achieve energy spreads as low as 0.25 eV to demonstrate field-driven ultrafast photo electron emission, in a system capable of much higher phase synchronization than its photon-driven counterpart. According to the researchers, their work will help reshape our understanding of strong field physics, and may very well light the way for entirely new types of electron emission systems. Read more. TECHNICAL ARTICLE