You're using an outdated browser. Please upgrade to a modern browser for the best experience.
Subject:
All Disciplines Arts & Humanities Biology & Life Sciences Business & Economics Chemistry & Materials Science Computer Science & Mathematics Engineering Environmental & Earth Sciences Medicine & Pharmacology Physical Sciences Public Health & Healthcare Social Sciences
Sort by:
Most Viewed Latest Alphabetical (A-Z) Alphabetical (Z-A)
Filter:
All Topic Review Biography Peer Reviewed Entry Video Entry
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.
  • 1.2K
  • 08 Jul 2022
Topic Review
Extinction-Coefficient Modulation of MoO3 Films
This entry focused on the application of the effective medium theory to describe the extinction coefficient (Qext) in molybdenum trioxide (MoO3) doped with different kinds of plasmonic nanoparticles, such as silver (Ag), gold (Au), and copper (Cu). Usually, in studies of these materials, it is normal to analyze the transmission or absorption spectra. However, the effect of this type or size of nanoparticles on the spectra is not as remarkable as the effect that is found by analyzing the Qext of MoO3. It was shown that the β-phase of MoO3 enhanced the intensity response of the Qext when compared to the α-phase of MoO3. With a nanoparticle size of 5 nm, the Ag-doped MoO3 was the configuration that presents the best response in Qext. On the other hand, Cu nanoparticles with a radius of 20 nm embedded in MoO3 was the configuration that presented intensities in Qext similar to the cases of Au and Ag nanoparticles. Therefore, implementing the effective medium theory can serve as a guide for experimental researchers for the application of these materials as an absorbing layer in photovoltaic cells. 
  • 1.2K
  • 20 Aug 2021
Topic Review
Optical-Coherence Tomography Angiography in AMD
Optical coherence tomography angiography (OCTA) is a non-invasive diagnostic instrument that has become indispensable for the management of age-related macular degeneration (AMD). OCTA allows quickly visualizing retinal and choroidal microvasculature, and in the last years, its use has increased in clinical practice as well as for research into the pathophysiology of AMD.
  • 1.2K
  • 22 Sep 2021
Topic Review
Lead Halide Perovskites Opto-Electronic Devices
In Lead Halide Perovskites Opto-Electronic Devices, we will discuss the development in the LHP-based functional devices in recent years. After a brief presentation of the LHP's properties, we will focus on the functional devices including lasers, photodetectors, and modulators. Then the fabrication of the LHP-based devices will be presented, which is followed by the summary and outlook.
  • 1.2K
  • 29 Apr 2021
Topic Review
On Ghost Imaging Studies for Information Optical Imaging
To understand, study, and optimize optical imaging systems from the information-theoretic viewpoint has been an important research subfield. However, the "direct point-to-point" image information acquisition mode of traditional optical imaging is lacking in "Coding-decoding" operation on the image information, and limits the development of further imaging capabilities. On the other hand, ghost imaging (GI) systems, combined with modern light-field modulation and digital photoelectric detection technologies, behave more in line with the modulation–demodulation information transmission mode compared to traditional optical imaging. This puts forward imperative demands and challenges for understanding and optimizing ghost imaging systems from the viewpoint of information theory, as well as bringing more development opportunities for the research field of information optical imaging. Here, several specific GI systems and studies with various extended imaging capabilities will be briefly reviewed. 
  • 1.2K
  • 14 Nov 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
  • 1.1K
  • 27 Dec 2022
Topic Review
Optical Parametric Oscillators and Raman Lasers
Optical parametric oscillators (OPOs) and Raman lasers are two nonlinear-based laser technologies that extend the spectral range of conventional inversion lasers. Power and brightness scaling of lasers are significant for many applications in industry, medicine, and defense. Considerable advances have been made to enhance the power and brightness of inversion lasers.
  • 1.1K
  • 30 Jan 2022
Topic Review
Mechanism of Surface-Enhanced Raman Spectroscopy
Raman spectroscopy is an analytical technique discovered by the Indian scientist C.V. Raman. It can be applied to analyze the molecular structure based on the molecular vibration and rotation information of scattering spectra. Benefiting from the recent advancements in material science, nanotechnology and optical technology, surface-enhanced Raman scattering (SERS) was developed and widely used in bioanalysis, clinical diagnosis and biomedical research. In SERS, Raman signals of molecules can be enhanced by six to ten orders of magnitude, owing to the electromagnetic field enhancement and chemical enhancement effects generated by nanostructures. The detection limit of SERS is even as low as the single-molecule level, so SERS is regarded as an ultrasensitive technique.
  • 1.1K
  • 21 Mar 2023
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
  • 1.1K
  • 06 Oct 2023
Topic Review
Precise Optical Modulation
Optoelectronic devices which play important roles in high-speed optical fiber networks can offer effective measurement methods for optoelectronic devices including optical modulators and photodetectors. Precise optical signal modulation is required for measurement applications.
  • 1.1K
  • 19 May 2021
Topic Review
Astrophotonic Spectrographs
Astrophotonics is the application of photonic technologies to channel, manipulate, and disperse light from one or more telescopes to achieve scientific objectives in astronomy in an efficient and cost-effective way. Utilizing photonic advantage for astronomical spectroscopy is a promising approach to miniaturizing the next generation of spectrometers for large telescopes. 
  • 1.1K
  • 23 Jun 2021
Topic Review
American Education
The landscape of education in the United States is in a state of flux, marked by ongoing debates about how best to reform the system to meet the needs of a diverse and changing society.
  • 1.1K
  • 31 Oct 2024
Topic Review
Challenges and Perspective for Lead-Free Double Perovskite-Based PDs
Lead halide perovskite has become a promising candidate for high-performance photodetectors (PDs) due to its attractive optical and electrical properties, such as high optical absorption coefficient, high carrier mobility, and long carrier diffusion length. However, the presence of highly toxic lead in these devices has limited their practical applications and even hindered their progress toward commercialization.
  • 1.1K
  • 06 Jul 2023
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. 
  • 1.1K
  • 31 Mar 2023
Topic Review
Mesoscale Dielectric Particles: Unusual Optical Effects
Mesoscale dielectric particles are mesostructures comprising both wavelength-scaled (i.e. dimensions comparable to wavelength) particles and particle chains or arrays. These particles are made of low loss dielectric materials having relatively low refractive index, namely the refractive index less than two. The main unusual optical effects in such structures are discussed below.
  • 1.1K
  • 01 Jan 2022
Topic Review
OCT Applications in GI Tract
Optical coherence tomography (OCT) is uniquely poised for advanced imaging in the gastrointestinal (GI) tract as it allows real-time, subsurface and wide-field evaluation at near-microscopic resolution, which may improve the current limitations or even obviate the need of superficial random biopsies in the surveillance of early neoplasias in the near future. OCT’s greatest impact so far in the GI tract has been in the study of the tubular esophagus owing to its accessibility, less bends and folds and allowance of balloon employment with optimal contact to aid circumferential imaging. Moreover, given the alarming rise in the incidence of Barrett's esophagus and its progression to adenocarcinoma in the U.S., OCT has helped identify pathological features that may guide future therapy and follow-up strategy. This review will explore the current uses of OCT in the gastrointestinal tract and future directions, particularly with non-endoscopic office-based capsule OCT and the use of artificial intelligence to aid in diagnoses.
  • 1.1K
  • 06 Nov 2020
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.
  • 1.1K
  • 17 Feb 2023
Topic Review
Fabrication of Semiconductor Optical Fibers
Because of their thermal and mechanical mismatch with typical glass materials, the fabrication of optical fibers from semiconductors is a considerable challenge for the field of materials science. As a result, the platform for optical fibers has been restricted to materials that are consistent with the typical fiber drawing techniques for an extended period. In 2006, a chemical deposition approach was used to create the initial example of a crystalline semiconductor optical fiber. As a result of this endeavor, different methods have been utilized in the fabrication of semiconductor optical fibers. Each of these methods has its own set of benefits and drawbacks. Since there have been no standardized techniques for fabricating these fibers, their production is relatively costly.
  • 1.1K
  • 31 Oct 2022
Topic Review
Applications of Droplet Microsystems in Optics and Photonics
The micro- and nano-machining techniques applied to solid materials have yielded remarkable success in the semiconductor industry by integrating complex functionalities into microscale devices, thus spearheading the modern electronics revolution. Extending similar miniaturization strategies to process and assemble soft matter for creating multileveled functional structures over various length scales presents significant scientific and practical potential. Soft matter, including liquid crystals (LC), colloids, polymers, and biological substances, exhibits widespread influence across nature, living organisms, daily life, and industry. The biomimetic properties, responsiveness to stimuli, and efficacy in controlled release and sensing make soft matter extensively applicable in biology and chemistry.
  • 1.1K
  • 18 Mar 2024
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.
  • 1.0K
  • 28 Apr 2021
  • Page
  • of
  • 7
Featured Entry Collections
>>

Featured Books

>>
Encyclopedia of COVID-19
Encyclopedia of Engineering
Encyclopedia of Social Sciences
Encyclopedia of Digital Society, Industry 5.0 and Smart City
Academic Video Service
Feedback