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Nature Communications Dec 2019Constructing colloidal particles into functional nanostructures, materials, and devices is a promising yet challenging direction. Many optical techniques have been...
Constructing colloidal particles into functional nanostructures, materials, and devices is a promising yet challenging direction. Many optical techniques have been developed to trap, manipulate, assemble, and print colloidal particles from aqueous solutions into desired configurations on solid substrates. However, these techniques operated in liquid environments generally suffer from pattern collapses, Brownian motion, and challenges that come with reconfigurable assembly. Here, we develop an all-optical technique, termed optothermally-gated photon nudging (OPN), for the versatile manipulation and dynamic patterning of a variety of colloidal particles on a solid substrate at nanoscale accuracy. OPN takes advantage of a thin surfactant layer to optothermally modulate the particle-substrate interaction, which enables the manipulation of colloidal particles on solid substrates with optical scattering force. Along with in situ optical spectroscopy, our non-invasive and contactless nanomanipulation technique will find various applications in nanofabrication, nanophotonics, nanoelectronics, and colloidal sciences.
Topics: Biophysical Phenomena; Colloids; Motion; Nanostructures; Optics and Photonics; Particle Size; Photons; Surface-Active Agents; Temperature
PubMed: 31831746
DOI: 10.1038/s41467-019-13676-3 -
Small (Weinheim An Der Bergstrasse,... Jun 2021Crystalline porous materials have been extensively explored for wide applications in many fields including nonlinear optics (NLO) for frequency doubling, two-photon... (Review)
Review
Crystalline porous materials have been extensively explored for wide applications in many fields including nonlinear optics (NLO) for frequency doubling, two-photon absorption/emission, optical limiting effect, photoelectric conversion, and biological imaging. The structural diversity and flexibility of the crystalline porous materials such as the metal-organic frameworks, covalent organic frameworks, and polyoxometalates provide numerous opportunities to orderly organize the dipolar chromophores and to systemically modify the type and concentration of these dipolar chromophores in the confined spaces, which are highly desirable for NLO. Here, the recent advances in the crystalline porous NLO materials are discussed. The second-order NLO of crystalline porous materials have been mainly devoted to the chiral and achiral structures, while the third-order NLO crystalline porous materials have been categorized into pure organic and hybrid organic/inorganic materials. Some representative properties and applications of these crystalline porous materials in the NLO regime are highlighted. The future perspective of challenges as well as the potential research directions of crystalline porous materials have been also proposed.
Topics: Metal-Organic Frameworks; Optics and Photonics; Photons; Porosity
PubMed: 33734577
DOI: 10.1002/smll.202006416 -
Sensors (Basel, Switzerland) Jan 2022In recent years, the biosensor research community has made rapid progress in the development of nanostructured materials capable of amplifying the interaction between... (Review)
Review
In recent years, the biosensor research community has made rapid progress in the development of nanostructured materials capable of amplifying the interaction between light and biological matter. A common objective is to concentrate the electromagnetic energy associated with light into nanometer-scale volumes that, in many cases, can extend below the conventional Abbé diffraction limit. Dating back to the first application of surface plasmon resonance (SPR) for label-free detection of biomolecular interactions, resonant optical structures, including waveguides, ring resonators, and photonic crystals, have proven to be effective conduits for a wide range of optical enhancement effects that include enhanced excitation of photon emitters (such as quantum dots, organic dyes, and fluorescent proteins), enhanced extraction from photon emitters, enhanced optical absorption, and enhanced optical scattering (such as from Raman-scatterers and nanoparticles). The application of photonic metamaterials as a means for enhancing contrast in microscopy is a recent technological development. Through their ability to generate surface-localized and resonantly enhanced electromagnetic fields, photonic metamaterials are an effective surface for magnifying absorption, photon emission, and scattering associated with biological materials while an imaging system records spatial and temporal patterns. By replacing the conventional glass microscope slide with a photonic metamaterial, new forms of contrast and enhanced signal-to-noise are obtained for applications that include cancer diagnostics, infectious disease diagnostics, cell membrane imaging, biomolecular interaction analysis, and drug discovery. This paper will review the current state of the art in which photonic metamaterial surfaces are utilized in the context of microscopy.
Topics: Biosensing Techniques; Microscopy; Optics and Photonics; Photons; Surface Plasmon Resonance
PubMed: 35161831
DOI: 10.3390/s22031086 -
Journal of Biomedical Optics Jul 2021Diffuse light is ubiquitous in biomedical optics and imaging. Understanding the process of migration of an initial photon population entering tissue to a completely...
SIGNIFICANCE
Diffuse light is ubiquitous in biomedical optics and imaging. Understanding the process of migration of an initial photon population entering tissue to a completely randomized, diffusely scattered population provides valuable insight to the interpretation and design of optical measurements.
AIM
The goal of this perspective is to present a brief, unifying analytical framework to describe how properties of light transition from an initial state to a distributed state as light diffusion occurs.
APPROACH
First, measurement parameters of light are introduced, and Monte Carlo simulations along with a simple analytical expression are used to explore how these individual parameters might exhibit diffusive behavior. Second, techniques to perform optical measurements are considered, highlighting how various measurement parameters can be leveraged to subsample photon populations.
RESULTS
Simulation results reinforce the fact that light undergoes a transition from a non-diffuse population to one that is first subdiffuse and then fully diffuse. Myriad experimental methods exist to isolate subpopulations of photons, which can be broadly categorized as source- and/or detector-encoded techniques, as well as methods of tagging the tissue of interest.
CONCLUSIONS
Characteristic properties of light progressing to diffusion can be described by some form of Gaussian distribution that grows in space, time, angle, wavelength, polarization, and coherence. In some cases, these features can be approximated by simpler exponential behavior. Experimental methods to subsample features of the photon distribution can be achieved or theoretical methods can be used to better interpret the data with this framework.
Topics: Computer Simulation; Diffusion; Monte Carlo Method; Optics and Photonics; Photons
PubMed: 34216136
DOI: 10.1117/1.JBO.26.7.070601 -
Journal of Biomedical Optics Jul 2002A method for the prediction of the average photon pathlength in turbid media has been developed. The method is based on spatially resolved diffuse reflectance with...
A method for the prediction of the average photon pathlength in turbid media has been developed. The method is based on spatially resolved diffuse reflectance with discrete source detector distances up to 2 mm. Light reflectance was simulated using a Monte Carlo technique with a one-layer model utilizing a wide range of optical properties, relevant to human skin. At a source detector separation of 2 mm, the pathlength can vary sixfold due to differences in optical properties. By applying various preprocessing and prediction techniques, the pathlength can be predicted with a root-mean-square error of approximately 5%. Estimation of the photon pathlength can be used, e.g., to remove the influence of optical properties on laser Doppler flowmetry perfusion readings, which are almost linearly related to the average photon pathlength.
Topics: Biophysical Phenomena; Biophysics; Humans; Laser-Doppler Flowmetry; Models, Theoretical; Monte Carlo Method; Nephelometry and Turbidimetry; Optics and Photonics; Photons; Skin
PubMed: 12175300
DOI: 10.1117/1.1482378 -
Sensors (Basel, Switzerland) Oct 2018Thanks to advanced semiconductor microfabrication technology, chip-scale integration and miniaturization of lab-on-a-chip components, silicon-based optical biosensors... (Review)
Review
Thanks to advanced semiconductor microfabrication technology, chip-scale integration and miniaturization of lab-on-a-chip components, silicon-based optical biosensors have made significant progress for the purpose of point-of-care diagnosis. In this review, we provide an overview of the state-of-the-art in evanescent field biosensing technologies including interferometer, microcavity, photonic crystal, and Bragg grating waveguide-based sensors. Their sensing mechanisms and sensor performances, as well as real biomarkers for label-free detection, are exhibited and compared. We also review the development of chip-level integration for lab-on-a-chip photonic sensing platforms, which consist of the optical sensing device, flow delivery system, optical input and readout equipment. At last, some advanced system-level complementary metal-oxide semiconductor (CMOS) chip packaging examples are presented, indicating the commercialization potential for the low cost, high yield, portable biosensing platform leveraging CMOS processes.
Topics: Biosensing Techniques; Equipment Design; Interferometry; Lab-On-A-Chip Devices; Miniaturization; Optics and Photonics; Photons; Silicon
PubMed: 30340405
DOI: 10.3390/s18103519 -
Likars'ka Sprava 2013Analyzed are the literature in the field of development and use nanobiophotonic technologies for laser and personalized medicine. Arguably, the origins of... (Review)
Review
Analyzed are the literature in the field of development and use nanobiophotonic technologies for laser and personalized medicine. Arguably, the origins of nanobiophotonic are closely tied in the first experimental realization of near-field optics, which enabled optical imaging beyond the diffraction limit. The information about the gist of nanobiophotonics and other photon-associations technologies (photonics, nanophotonics, biophotonics, nanooptics, plasmonics, nanospectroscopy, laser and personalized medicine) is summarized. Nanobiophotonics is the use of light to image, probe and manipulate biological materials. The particular strength of nanobiophotonics is thet in ideal case it retains of the light for permits live cell sensing. The area of nanobiophotonics technologies is too broad to possible capture all aspects nano-analitic directions and biomedical research within the last years.
Topics: Biotechnology; Laser Therapy; Nanotechnology; Optics and Photonics; Photons; Precision Medicine
PubMed: 23951906
DOI: No ID Found -
Journal of Synchrotron Radiation Sep 2019X-ray photon beam diagnostic imagers are located at 24 positions in the European XFEL beam transport system to characterize the X-ray beam properties, and to give...
X-ray photon beam diagnostic imagers are located at 24 positions in the European XFEL beam transport system to characterize the X-ray beam properties, and to give feedback for tuning and optimization of the electron acceleration and orbit, the undulators, and the X-ray optics. One year of commissioning allowed experience to be gained with these imagers, which will be reported here. The sensitive Spontaneous Radiation imager is useful for various investigations in spontaneous radiation mode: for undulator adjustments and for low-signal imaging applications. The high-resolution Free-Electron Laser imager, 10 µm spatial resolution, is extensively used for the monitoring of beam position, spot size and shape, gain curve measurements, and also for beam-intensity monitoring. The wide field-of-view pop-in monitors (up to 200 mm) are regularly used for alignment and tuning of the various X-ray optical components like mirrors, slits and monochromators, and also for on-line beam control of a stable beam position at the instruments. The Exit Slit imager after the soft X-ray monochromator provides spectral information of the beam together with multi-channel plate based single-pulse gating. For particular use cases, these special features of the imagers are described. Some radiation-induced degradation of scintillators took place in this initial commissioning phase, providing useful information for better understanding of damage thresholds. Visible-light radiation in the beam pipe generated by upstream bending magnets caused spurious reflections in the optical system of some of the imagers which can be suppressed by aluminium-coated scintillating screens.
Topics: Artifacts; Equipment Design; Europe; Lasers; Optics and Photonics; Photons; Radiation Monitoring; X-Rays
PubMed: 31490136
DOI: 10.1107/S1600577519008737 -
Optics Letters Sep 2003A major obstacle in the race to develop two-photon fluorescence endoscopy is the use of complicated bulk optics to transmit an ultrashort-pulsed laser beam and return...
A major obstacle in the race to develop two-photon fluorescence endoscopy is the use of complicated bulk optics to transmit an ultrashort-pulsed laser beam and return the emitted fluorescence signal. We describe an all-fiber two-photon fluorescence microendoscope based on a single-mode optical fiber coupler, a microprism, and a gradient-index rod lens. It is found that the new endoscope exhibits an axial resolution of 3.2 microm and is capable of imaging transverse cross sections of internal cylindrical structures as small as approximately 3.0 mm in diameter. This device demonstrates the potential for developing a real-time diagnostic tool for biomedical research without the need for surgical biopsy and may find applications in photodynamic therapy, microsurgery, and early cancer detection.
Topics: Endoscopy; Equipment Design; Microscopy, Fluorescence; Optics and Photonics; Photons
PubMed: 12956376
DOI: 10.1364/ol.28.001552 -
Nature Communications Sep 2022Inspired by insect compound eyes (CEs) that feature unique optical schemes for imaging, there has recently been growing interest in developing optoelectronic CE cameras...
Inspired by insect compound eyes (CEs) that feature unique optical schemes for imaging, there has recently been growing interest in developing optoelectronic CE cameras with comparable size and functions. However, considering the mismatch between the complex 3D configuration of CEs and the planar nature of available imaging sensors, it is currently challenging to reach this end. Here, we report a paradigm in miniature optoelectronic integrated CE camera by manufacturing polymer CEs with 19~160 logarithmic profile ommatidia via femtosecond laser two-photon polymerization. In contrast to μ-CEs with spherical ommatidia that suffer from defocusing problems, the as-obtained μ-CEs with logarithmic ommatidia permit direct integration with a commercial CMOS detector, because the depth-of-field and focus range of all the logarithmic ommatidia are significantly increased. The optoelectronic integrated μ-CE camera enables large field-of-view imaging (90°), spatial position identification and sensitive trajectory monitoring of moving targets. Moreover, the miniature μ-CE camera can be integrated with a microfluidic chip and serves as an on-chip camera for real-time microorganisms monitoring. The insect-scale optoelectronic μ-CE camera provides a practical route for integrating well-developed planar imaging sensors with complex micro-optics elements, holding great promise for cutting-edge applications in endoscopy and robot vision.
Topics: Animals; Insecta; Lasers; Optics and Photonics; Photons; Polymers
PubMed: 36163128
DOI: 10.1038/s41467-022-33072-8