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Topic Review
Label-Free Multiphoton Microscopy
Label-free microscopy methods rely on photophysical processes to generate signals through specific interactions with biological molecules and offer great potential for basic research and clinical applications.
  • 619
  • 28 Apr 2021
Topic Review
Ultrafast Fiber Technologies for Compact Laser Wake Field
Technologies, performances and maturity of ultrafast fiber lasers and fiber delivery of ultrafast pulses are used for the medical deployment of laser-wake-field acceleration (LWFA). The compact ultrafast fiber lasers produce intense laser pulses with flexible hollow-core fiber delivery to facilitate electron acceleration in the laser-stimulated wake field near treatment site, empowering endoscopic LWFA brachytherapy. With coherent beam combination of multiple fiber amplifiers, the advantages of ultrafast fiber lasers are further extended to bring in more capabilities in compact LWFA applications.
  • 619
  • 08 Jul 2022
Topic Review
Coronagraph
A coronagraph is a telescopic attachment designed to block out the direct light from a star so that nearby objects – which otherwise would be hidden in the star's bright glare – can be resolved. Most coronagraphs are intended to view the corona of the Sun, but a new class of conceptually similar instruments (called stellar coronagraphs to distinguish them from solar coronagraphs) are being used to find extrasolar planets and circumstellar disks around nearby stars as well as host galaxies in quasars and other similar objects with active galactic nuclei (AGN).
  • 616
  • 23 Nov 2022
Topic Review
Perovskite Quantum Dots
The excellent luminescence properties of perovskite quantum dots (PQDs), including wide excitation wavelength range, adjustable emission wavelength, narrow full width at half maximum (FWHM), and high photoluminescence quantum yield (PLQY), highly match the application requirements in emerging displays.
  • 609
  • 14 Jul 2022
Topic Review
Central High-Order Aberrations and Accommodation
High-order aberrations (HOAs) are optical defects that degrade the image quality. They change with factors such as pupil diameter, age, and accommodation. The changes in optical aberrations during accommodation are mainly due to lens shape and position changes. Primary spherical aberration (Z(4.0)) is closely related to accommodation and some studies suggested that it plays an important role in the control of accommodation. Furthermore, central and peripheral HOAs vary with refractive error and seem to influence eye growth and the onset and progression of myopia. The variations of central and peripheral HOAs during accommodation also appear to be different depending on the refractive error. Central and peripheral high-order aberrations are closely related to accommodation and influence the accuracy of the accommodative response and the progression of refractive errors, especially myopia. 
  • 609
  • 31 Mar 2023
Topic Review
Metasurface Photodetectors
Photodetectors are the essential building blocks of a wide range of optical systems. Typical photodetectors only convert the intensity of light electrical output signals, leaving other electromagnetic parameters, such as the frequencies, phases, and polarization states unresolved. 
  • 603
  • 26 Jan 2022
Topic Review
Liquid Crystal-Tuned Planar Optics in Terahertz Range
Terahertz waves of higher frequencies compared to microwave and radio frequency have shown great potential in radar detection and high-speed wireless communication. To spatially control the wavefront of terahertz beams, various novel components, such as terahertz filters, polarization converters and lenses, have been investigated. Metamaterials and metasurfaces have become the most promising technique for the free manipulation of terahertz waves. Metadevices integrated with liquid crystals have been widely used in active terahertz devices.
  • 599
  • 17 Feb 2023
Topic Review
Enchroma
EnChroma lenses are glasses designed to improve and modify some aspects of color vision deficiency for color blind people. The glasses were invented by Dr. Donald McPherson in 2002. Wearing the glasses results in subtle differences when color blind people look longer and more carefully.
  • 599
  • 17 Nov 2022
Topic Review
Polymer Waveguide-Based Sensors
The optical waveguide (WG) is one of the fundamental components of integrated photonics. Polymer WGs can operate in either single-mode (with core diameters between 2 μm and 5 μm) or multimode (with core dimensions generally between 30 μm and 500 μm) regimes. They are both entirely consistent with the matching optical fiber type due to the similar mode field diameter. A WG is simply utilized as a light link to connect external instruments to a sampling point or an optical sensing element in an extrinsic sensor. In biomedicine, environmental monitoring, process control, and safety, extrinsic sensors are already widely employed.
  • 587
  • 08 Mar 2023
Topic Review
SERS-Based Plasmonic Sensors for Biosensing Applications
Surface-enhanced Raman spectroscopy/scattering (SERS) has evolved into a popular tool for applications in biology and medicine owing to its ease-of-use, non-destructive, and label-free approach. Advances in plasmonics and instrumentation have enabled the realization of SERS’s full potential for the trace detection of biomolecules, disease diagnostics, and monitoring.
  • 578
  • 07 Mar 2023
Biography
John Desmond Bernal
John Desmond Bernal FRS (/bərˈnɑːl/; 10 May 1901 – 15 September 1971) was an Irish scientist who pioneered the use of X-ray crystallography in molecular biology. He published extensively on the history of science. In addition, Bernal was a political supporter of communism and wrote popular books on science and society. His family was Irish, of mixed Italian and Spanish/Portuguese[1] Se
  • 571
  • 08 Dec 2022
Biography
Mikhail Mikhaylovich Rusinov
Mikhail Mikhaylovich Rusinov (Russian: Михаи́л Миха́йлович Руси́нов, 11 February 1909 – 29 September 2004) was an outstanding Russian scientist, specialising in optics. Mikhail Rusinov co-founded the USSR Science School of Computational Optics and discovered several optical phenomena, including aberration vignetting (1938), projection centre distortion (1957), and exi
  • 570
  • 27 Dec 2022
Topic Review
High-Performance Silicon Optoelectronic Devices Based on Graphene
Graphene—a two-dimensional allotrope of carbon in a single-layer honeycomb lattice nanostructure—has several distinctive optoelectronic properties that are highly desirable in advanced optical communication systems. Meanwhile, silicon photonics is a promising solution for the next-generation integrated photonics, owing to its low cost, low propagation loss and compatibility with CMOS fabrication processes.
  • 554
  • 19 Jan 2022
Topic Review
Waveguide-Enhanced Raman Spectroscopy
Photonic chip-based methods for spectroscopy are of considerable interest due to their applicability to compact, low-power devices for the detection of small molecules. Waveguide-enhanced Raman spectroscopy (WERS) has emerged over the past decade as a particularly interesting approach. WERS utilizes the evanescent field of a waveguide to generate Raman scattering from nearby analyte molecules, and then collects the scattered photons back into the waveguide. The large interacting area and strong electromagnetic field provided by the waveguide allow for significant enhancements in Raman signal over conventional approaches.
  • 551
  • 29 Dec 2022
Topic Review
Advancement in UV-Visible-IR Camouflage Textiles & Camouflage Physics
Optical theory of Camouflage engineering has been invented for defence protection. This optical theory can be implemented by defence scientists to explore camouflage products and multidimensional branches of optical technologies. Advancement in ultraviolet-visible-near infrared (UV-Vis-IR) camouflage engineering has been designed for defence protection. Camouflage physics has been explained through camouflage textiles and camouflage materials. This technique of camouflage engineering can be explored to defence technology for the design and manufacturing of combat product against multidimensional combat backgrounds such as dry leaves, green leaves, tree bark-woodland combat background; water-marine combat background; sand-desertland combat background; stone-stoneland combat background; snow-snowland combat background; sky combat background; ice-iceland combat background and concrete-concreteland combat background (DGTWSICB). This is a novel addition of camouflage technology for the engineering progress of camouflage product design. Hence, camouflage engineering has been briefly reported by “Anowar Hossain’s invention of camouflage physics at PhD School, first version submitted to Nobel committee for Nobel nomination in 2023 under affiliation of RMIT University”. http://dx.doi.org/10.13140/RG.2.2.29936.23048, https://doi.org/10.5281/zenodo.8286832
  • 551
  • 06 Oct 2023
Topic Review
Nano-grating Assisted Light Absorption and MSM-PDs Performance
The nano-grating assisted MSM-PDs are preordained to be decorous for many emerging and existing communication device applications. There have been a significant number of research works conducted on the implementation of nano-gratings, and still, more researches are ongoing to raise the performance of MSM-PDs particularly, in terms of enhancing the light absorption potentialities.
  • 547
  • 15 Dec 2021
Topic Review
GaN-Based Resonant-Cavity Light-Emitting Diodes Grown on Si
GaN-on-Si resonant-cavity light-emitting diodes (RCLEDs) have been successfully fabricated through wafer bonding and Si substrate removal. 
  • 544
  • 17 Jan 2022
Topic Review
Liquid Mirror Telescope
Liquid mirror telescopes are telescopes with mirrors made with a reflective liquid. The most common liquid used is mercury, but other liquids will work as well (for example, low melting alloys of gallium). The liquid and its container are rotated at a constant speed around a vertical axis, which causes the surface of the liquid to assume a paraboloidal shape, suitable for use as the primary mirror of a reflecting telescope. The rotating liquid assumes the paraboloidal shape regardless of the container's shape. To reduce the amount of liquid metal needed, and thus weight, a rotating mercury mirror uses a container that is as close to the necessary parabolic shape as possible. Liquid mirrors can be a low cost alternative to conventional large telescopes. Compared to a solid glass mirror that must be cast, ground, and polished, a rotating liquid metal mirror is much less expensive to manufacture. Isaac Newton noted that the free surface of a rotating liquid forms a circular paraboloid and can therefore be used as a telescope, but he could not actually build one because he had no way to stabilize the speed of rotation. The concept was further developed by Ernesto Capocci of the Naples Observatory (1850), but it was not until 1872 that Henry Skey of Dunedin, New Zealand constructed the first working laboratory liquid mirror telescope. Another difficulty is that a liquid metal mirror can only be used in zenith telescopes, i.e., that look straight up, so it is not suitable for investigations where the telescope must remain pointing at the same location of inertial space (a possible exception to this rule may exist for a mercury mirror space telescope, where the effect of Earth's gravity is replaced by artificial gravity, perhaps by rotating the telescope on a very long tether, or propelling it gently forward with rockets). Only a telescope located at the North Pole or South Pole would offer a relatively static view of the sky, although the freezing point of mercury and the remoteness of the location would need to be considered. A very large telescope already exists at the South Pole, but the North Pole is located in the Arctic Ocean. The mercury mirror of the Large Zenith Telescope in Canada was the largest liquid metal mirror ever built. It had a diameter of six meters, and rotated at a rate of about 8.5 revolutions per minute. It is now decommissioned. This mirror was a test, built for $1 million but it was not suitable for astronomy because of the test site's weather. They are now planning to build a larger 8 meter liquid mirror telescope ALPACA for astronomical use and a larger project called LAMA with 66 individual 6.15 meter telescopes with a total collecting power equal to a 55 meter telescope, resolving power of a 70 meter scope.
  • 543
  • 08 Oct 2022
Topic Review
The Role of Probiotics in Skin Health
By regulating skin health and gut–skin axis interactions, probiotics can be used as potential management tools to suppress and improve skin diseases in multiple ways, including decreasing oxidative stress, suppressing inflammatory responses, and keeping immune effects.
  • 541
  • 24 Jul 2023
Topic Review
An introduction to the Recent Advances in Nanophotonics
Nanophotonics is an emerging multidisciplinary frontier of science and engineering. Its high potential in contributing to the development of many areas of technology makes nanophotonics a focus of interest for many researchers from different fields.
  • 539
  • 09 Feb 2022
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