Optical planar waveguide for cell counting.
Ontology highlight
ABSTRACT:
SUBMITTER: Leblanc J
PROVIDER: S-EPMC3277603 | biostudies-other | 2012 Jan
REPOSITORIES: biostudies-other
Similar Datasets
Project description:Optical planar waveguide sensors, able to detect and process information from the environment in a fast, cost-effective, and remote fashion, are of great interest currently in different application areas including security, metrology, automotive, aerospace, consumer electronics, energy, environment, or health. Integration of networks of these systems together with other optical elements, such as light sources, readout, or detection systems, in a planar waveguide geometry is greatly demanded towards more compact, portable, and versatile sensing platforms. Herein, we report an optical temperature sensor with a planar waveguide architecture integrating inkjet-printed luminescent light coupling-in and readout elements with matched emission and excitation. The first luminescent element, when illuminated with light in its absorption band, emits light that is partially coupled into the propagation modes of the planar waveguide. Remote excitation of this element can be performed without the need for special alignment of the light source. A thermoresponsive liquid crystal-based film regulates the amount of light coupled out from the planar waveguide at the sensing location. The second luminescent element partly absorbs the waveguided light that reaches its location and emits at longer wavelengths, serving as a temperature readout element through luminescence intensity measurements. Overall, the ability of inkjet technology to digitally print luminescent elements demonstrates great potential for the integration and miniaturization of light coupling-in and readout elements in optical planar waveguide sensing platforms.
| S-EPMC6651219 | biostudies-literature
Project description:In this paper, a general method for analyzing arbitrary planar negative-refractive-index (NRI) multilayer slab optical waveguide structures was proposed. Some degenerated examples were introduced to prove the accuracy of the proposed method. The analytical and numerical results show excellent agreement. The method can also be degenerated to analyze arbitrary planar conventional optical waveguide structures. Based on this general method, the analysis and calculation of any kinds of planar NRI slab optical waveguide structures and planar conventional optical waveguide structures can be achieved easily.
| S-EPMC7486898 | biostudies-literature
Project description:This work reports on further development of an optical biosensor for the in vitro detection of mycotoxins (in particular, aflatoxin B1) using a highly sensitive planar waveguide transducer in combination with a highly specific aptamer bioreceptor. This sensor is built on a SiO2-Si3N4-SiO2 optical planar waveguide (OPW) operating as a polarization interferometer (PI), which detects a phase shift between p- and s-components of polarized light propagating through the waveguide caused by the molecular adsorption. The refractive index sensitivity (RIS) of the recently upgraded PI experimental setup has been improved and reached values of around 9600 rad per refractive index unity (RIU), the highest RIS values reported, which enables the detection of low molecular weight analytes such as mycotoxins in very low concentrations. The biosensing tests yielded remarkable results for the detection of aflatoxin B1 in a wide range of concentrations from 1 pg/mL to 1 ?g/mL in direct assay with specific DNA-based aptamers. Graphical abstract Optical planar waveguide polarization interferometry biosensor for detection of aflatoxin B1 using specific aptamer.
| S-EPMC6881424 | biostudies-literature
Project description:High index optical waveguide devices such as slab waveguides, strip waveguides and fibers play extremely important roles in a wide range of modern applications including telecommunications, sensing, lasing, interferometry, and resonant amplification. Yet, transposing these advantageous applications from optics to acoustics remains a fundamental practical challenge, since most materials exhibit refractive indices lower than that of air for sound waves. Here, we demonstrate the relevance of acoustic metamaterials for tackling this pivotal problem. More specifically, we consider a metamaterial built from subwavelength air-filled acoustic pipes engineered to effectively exhibit a higher refractive index than homogenous air. We show that such medium can be employed to realize acoustic equivalents of dielectric slab or strip waveguides, and optical fibers. Unlike conventional acoustic pipes, our guiding approach allows the waveguide to remain open to the external medium, which opens an abundance of new opportunities in noise management, medical imaging, underwater communication systems, and sensing.
| S-EPMC6039535 | biostudies-literature
Project description:Harnessing artificial optical magnetism has previously required complex two- and three-dimensional structures, such as nanoparticle arrays and split-ring metamaterials. By contrast, planar structures, and in particular dielectric/metal multilayer metamaterials, have been generally considered non-magnetic. Although the hyperbolic and plasmonic properties of these systems have been extensively investigated, their assumed non-magnetic response limits their performance to transverse magnetic (TM) polarization. We propose and experimentally validate a mechanism for artificial magnetism in planar multilayer metamaterials. We also demonstrate that the magnetic properties of high-index dielectric/metal hyperbolic metamaterials can be anisotropic, leading to magnetic hyperbolic dispersion in certain frequency regimes. We show that such systems can support transverse electric polarized interface-bound waves, analogous to their TM counterparts, surface plasmon polaritons. Our results open a route for tailoring optical artificial magnetism in lithography-free layered systems and enable us to generalize the plasmonic and hyperbolic properties to encompass both linear polarizations.
| S-EPMC5773539 | biostudies-literature
Project description:The capability to count cells from biofluids at low cost has important diagnostic implications in resource-poor settings. Many approaches have been developed to address this important need, and while most envision a low per-test cost, the detector instrument can be quite expensive. In this report, we present a novel device that enables low-cost and rapid counting of cells from a drop of blood. We demonstrate a shallow, buried, planar waveguide fabricated by ion exchange in glass that underlies a microfluidic structure for capturing cells. Laser light transmitted through the waveguide was attenuated by the number of metal nanoparticles tagged to the cells because of the interaction of the metal particles with the evanescent field of the waveguide. Calibration of the sensor using bead-tagged lymphocytes captured from human blood showed that the sensor could semi-quantitatively count as few as 100 cells/µL of blood. This technology enables the enumeration of specifically captured cells, allowing for a point-of-care, hand-held device for fast and affordable cell counting in screening, remote, or resource-poor settings.
| S-EPMC3313547 | biostudies-other
Project description:Physical unclonable functions are the physical equivalent of one-way mathematical transformations that, upon external excitation, can generate irreversible responses. Exceeding their mathematical counterparts, their inherent physical complexity renders them resilient to cloning and reverse engineering. When these features are combined with their time-invariant and deterministic operation, the necessity to store the responses (keys) in non-volatile means can be alleviated. This pivotal feature, makes them critical components for a wide range of cryptographic-authentication applications, where sensitive data storage is restricted. In this work, a physical unclonable function based on a single optical waveguide is experimentally and numerically validated. The system's responses consist of speckle-like images that stem from mode-mixing and scattering events of multiple guided transverse modes. The proposed configuration enables the system's response to be simultaneously governed by multiple physical scrambling mechanisms, thus offering a radical performance enhancement in terms of physical unclonability compared to conventional optical implementations. Additional features like physical re-configurability, render our scheme suitable for demanding authentication applications.
| S-EPMC6018550 | biostudies-literature
Project description:High quality-factor (Q) optical resonators are a key component for ultra-narrow linewidth lasers, frequency stabilization, precision spectroscopy and quantum applications. Integration in a photonic waveguide platform is key to reducing cost, size, power and sensitivity to environmental disturbances. However, to date, the Q of all-waveguide resonators has been relegated to below 260 Million. Here, we report a Si3N4 resonator with 422 Million intrinsic and 3.4 Billion absorption-limited Qs. The resonator has 453 kHz intrinsic, 906 kHz loaded, and 57 kHz absorption-limited linewidths and the corresponding 0.060 dB m-1 loss is the lowest reported to date for waveguides with deposited oxide upper cladding. These results are achieved through a careful reduction of scattering and absorption losses that we simulate, quantify and correlate to measurements. This advancement in waveguide resonator technology paves the way to all-waveguide Billion Q cavities for applications including nonlinear optics, atomic clocks, quantum photonics and high-capacity fiber communications.
| S-EPMC7876138 | biostudies-literature
Project description:Quantum engineering using photonic structures offer new capabilities for atom-photon interactions for quantum optics and atomic physics, which could eventually lead to integrated quantum devices. Despite the rapid progress in the variety of structures, coherent excitation of the motional states of atoms in a photonic waveguide using guided modes has yet to be demonstrated. Here, we use the waveguide mode of a hollow-core photonic crystal fibre to manipulate the mechanical Fock states of single atoms in a harmonic potential inside the fibre. We create a large array of Schrödinger cat states, a quintessential feature of quantum physics and a key element in quantum information processing and metrology, of approximately 15000 atoms along the fibre by entangling the electronic state with the coherent harmonic oscillator state of each individual atom. Our results provide a useful step for quantum information and simulation with a wide range of photonic waveguide systems.
| S-EPMC7575543 | biostudies-literature
Project description:At present, most of the reported planar pentacoordinate clusters are similar to the isoelectronic substitution of CAl5+, with 18 counting electrons. Meanwhile, the regular planar pentacoordinate boron systems are rarely reported. Hereby, a sulphur-bridged BAl5S5+ system with a five-pointed star configuration and 17 counting electrons is identified at the global energy minimum through the particle-swarm optimization method, based on the previous recognition on bridged sulphur as the peripheral tactics to the stable planar tetracoordinate carbon and boron. Its outstanding stability has been demonstrated by thermodynamic analysis at 900 K, electronic properties and chemical bonding analysis. This study provides adequately theoretical basis and referable data for its experimental capture and testing.
| S-EPMC8433653 | biostudies-literature