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Topic Review
Wavefront shaping concepts in OCT
Optical coherence tomography (OCT) enables three-dimensional imaging with resolution on the micrometer scale. The technique relies on the time-of-flight gated detection of light scattered from a sample and has received enormous interest in applications as versatile as non-destructive testing, metrology and non-invasive medical diagnostics. However, in strongly scattering media such as biological tissue, the penetration depth and imaging resolution are limited. Combining OCT imaging with wavefront shaping approaches significantly leverages the capabilities of the technique by controlling the scattered light field through manipulation of the field incident on the sample.
  • 1.5K
  • 24 Dec 2020
Topic Review
Scanless and Detectorless Imaging System
Optical feedback interferometry is a versatile and robust technology for both sensing and imaging applications, available at all wavelengths were a semiconductor laser exists, from 270 nm to 120 μm. It can be easily adapted to fiber integrated systems and promises to be compatible also to silicon photonics.
  • 1.4K
  • 18 Nov 2020
Topic Review
Liquid Crystal Waveguide Structures
Liquid crystal materials can be used to make either a core, in which light beams can be confined, or a cladding of optical waveguides.
  • 1.4K
  • 02 Nov 2021
Topic Review
Generation/Amplification of Mid-Infrared Few-Cycle Pulse
The mid-infrared (MIR) wavelength is usually defined in the range of 2–20 μm (500–5000 cm−1). With its unique properties and wide application prospects, lasers in this band have attracted a great deal of attention from researchers all over the world.
  • 1.4K
  • 30 Jul 2021
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.
  • 1.4K
  • 24 Jul 2023
Topic Review
Photoacoustic Approach in the Characterization of Nanostructured Materials
The photoacoustic (PA) effect is the generation of pressure perturbations in a medium due to its heating with non-stationary electromagnetic radiation. A new generation of sensors can be engineered based on the sensing of several markers to satisfy the conditions of the multimodal detection principle. From this point of view, photoacoustic-based sensing approaches are essential. The photoacoustic effect relies on the generation of light-induced deformation (pressure) perturbations in media, which is essential for sensing applications since the photoacoustic response is formed due to a contrast in the optical, thermal, and acoustical properties. It is also particularly important to mention that photoacoustic light-based approaches are flexible enough for the measurement of thermal/elastic parameters. Moreover, the photoacoustic approach can be used for imaging and visualization in material research and biomedical applications. The advantages of photoacoustic devices are their compact sizes and the possibility of on-site measurements, enabling the online monitoring of material parameters. The latter has significance for the development of various sensing applications, including biomedical ones, such as monitoring of the biodistribution of biomolecules. To extend sensing abilities and to find reliable measurement conditions, one needs to clearly understand all the phenomena taking place during energy transformation during photoacoustic signal formation. 
  • 1.4K
  • 21 Mar 2022
Topic Review
Direct Ultrafast Laser Processing
Direct ultrafast laser processing is nowadays considered the most flexible technique allowing to generate complex 3D optical functions in bulk glasses. The fact that the built-in optical element is embedded in the material brings several advantages in terms of prototype stability and lifetime, but equally in terms of complexity and number of possible applications, due to the 3D design. The generated optical functions, and in particular the single mode character of the light guiding element alongside the accessibility toward different spectral windows, depend on the refractive index contrast that can be achieved within the material transparency window and on the characteristic dimensions of the optical modification. In particular, the accessibility to the infrared and mid-infrared spectral domains, and to the relevant applications in sensing and imaging, requires increasing the cross-section of the guiding element in order to obtain the desired normalized frequency. Moreover, efficient signal extraction from the transported light requires nanometer size void-like index structures. All this demands a thorough knowledge and an optimal control of the material response within the interaction with the ultrafast laser pulse.
  • 1.4K
  • 25 Jun 2021
Topic Review
Optical Detection of Pathogenic Bacteria
The optical detection of pathogenic bacteria is a growing area of ongoing research for clinically-focused applications. Different modalities, like vibrational spectroscopy, fluorescence, scattering- and polarization-based systems, have the potential to provide information about the biomolecular and morphological characteristics of a species for sample identification and differentiation. Additionally, growth pattern recognition, single-cell versus biofilm formations, cell motility and viability, cell mutation, and antibiotic resistance status can be studied with various optical modalities, providing great potential for rapid characterization of disease-causing pathogens.
  • 1.4K
  • 03 Dec 2020
Topic Review
Nanomaterials for Optical Coherence Tomography in Nanodentistry
There is already a societal awareness of the growing impact of nanoscience and nanotechnology, with nanomaterials (with at least one dimension less than 100 nm) now incorporated in items as diverse as mobile phones, clothes or dentifrices. In the healthcare area, nanoparticles of biocompatible materials have already been used for cancer treatment or bioimaging enhancement. Nanotechnology in dentistry, or nanodentistry, has already found some developments in dental nanomaterials for caries management, restorative dentistry and orthodontic adhesives. 
  • 1.4K
  • 01 Mar 2022
Topic Review
Holographic Optical Tweezers for Biomedical Applications
Holographic optical tweezers (HOT) is a programmable technique used for manipulation of microsized samples. In combination with computer-generation holography (CGH), a spatial light modulator reshapes the light distribution within the focal area of the optical tweezers. HOT can be used to realize real-time multiple-point manipulation in fluid, and this is useful in biological research.
  • 1.4K
  • 27 Oct 2022
Topic Review
Optical Polarization-Based Measurement for Peptides and Amino Acids
Polarization-based optical measurement methods are very useful in the analysis of the molecular orientations of materials, and, thus, these methods are implemented in numerous material-science studies, including into the characterization of amino acids’ (SAPA)  micro- and nanostructures.
  • 1.4K
  • 21 Mar 2022
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
  • 1.4K
  • 08 Dec 2022
Topic Review
Liquid Crystal Lenses
Liquid crystal (LC) lenses may be used by themselves or as a supplement of glass lenses, e.g., to tune up the power of the glass lens within a certain range, with functionality equivalent to commercial progressive lenses, but with improved performance since the power of the whole lens is modified by a sensor providing autofocus, as in digital cameras.
  • 1.3K
  • 29 Dec 2023
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).
  • 1.3K
  • 23 Nov 2022
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.
  • 1.3K
  • 07 Mar 2023
Topic Review Peer Reviewed
High-Power Lasers
High-power lasers play an important role in modern science, industry, and medicine. A significant milestone was reached on 5 December 2022, when Inertial Confinement Nuclear Fusion (ICF) achieved scientific breakeven, releasing more energy than the input laser energy. Additionally, Extreme Ultraviolet Lithography (EUVL) has enabled the development of microchips with 3 nm process nodes, marking a leap in semiconductor technology. These examples, together with the recent achievement of 10 PW (1015 W) laser output, herald remarkable advancements in technology and science. Laser systems are broadly classified based on their operating regimes into two main categories: Continuous Wave (CW) operation, where the laser is continuously pumped and emits a steady beam of light, and the pulsed regime, in which the laser produces single or multiple pulses at various repetition rates. This review will primarily focus on pulsed laser systems, exploring their various types and recent technological advancements.
  • 1.3K
  • 09 Aug 2024
Topic Review
Radiation-Balanced Lasers
Radiation-balanced lasers can provide lasing without detrimental heating of laser medium. This new approach to the design of optically pumped rare-earth (RE)-doped solid-state lasers is provided by balancing the spontaneous and stimulated emission within the laser medium. It is based on the principle of anti-Stokes fluorescence cooling of RE-doped low-phonon solids.
  • 1.3K
  • 13 Sep 2021
Topic Review
3D Live Cell Imaging Challenges
Relevant samples are described and various problems and challenges—including 3D Challenges of 3D imaging by optical sectioning, light scattering and phototoxicity—are addressed. Furthermore, enhanced methods of wide-field or laser scanning microscopy together with some relevant examples and applications are summarized. In the future one may profit from a continuous increase in microscopic resolution, but also from molecular sensing techniques in the nanometer range using e.g., non-radiative energy transfer (FRET).
  • 1.3K
  • 23 Aug 2021
Topic Review
Intensity-Modulated Polymer Optical Fiber-Based Refractive Index Sensor
The simple and highly sensitive measurement of the refractive index (RI) of liquids is critical for designing the optical instruments and important in biochemical sensing applications. Intensity modulation-based polymer optical fiber (POF) RI sensors have a lot of advantages including low cost, easy fabrication and operation, good flexibility, and working in the visible wavelength.
  • 1.3K
  • 25 Apr 2022
Topic Review
Ultrafast Laser in Orthopedic Surgery
The potential of ultrafast lasers (pico- to femtosecond) in orthopedics-related procedures has been studied extensively for clinical adoption. As compared to conventional laser systems with continuous wave or longer wave pulse, ultrafast lasers provide advantages such as higher precision and minimal collateral thermal damages. Translation to surgical applications in the clinic has been restrained by limitations of material removal rate and pulse average power, whereas the use in surface texturing of implants has become more refined to greatly improve bioactivation and osteointegration within bone matrices.
  • 1.2K
  • 07 May 2022
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