The present invention relates to an optical fiber for use in a system for detection of one or more compounds in a fluid. The optical fiber (100, 101, 202) comprising at least two binding portions (102, 104, 118, 210, 211, 212) separated from each other along the longitudinal direction (106) of the optical fiber (100, 101, 202), wherein each of the at least two binding portions (102, 104, 118, 210, 211, 212) comprises a plasmonic structure (120) and/or a SERS structure (121), and a binding material (126) for binding of one or more compounds, wherein at least two binding portions (102, 104, 118, 210, 211, 212) are arranged for binding the same compound or compounds, wherein the optical fiber (100, 101, 202) is arranged for receiving light and transmitting light to each of the at least two binding portions, wherein each of the at least two binding portions (102, 104, 118, 210, 211, 212) is arranged such that light transmitted through that binding portion (102, 104, 118, 210, 211, 212) without bound compound is different compared to light transmitted through that binding portion (102, 104, 118, 210, 211, 212) with bound compound, or light reflected back from that binding portion (102, 104, 118, 210, 211, 212) without bound compound is different compared to light reflected back from that binding portion (102, 104, 118, 210, 211, 212) with bound compound. The present invention further relates to a system (200) for detection of one or more compounds in a fluid (103) and an optical fiber (100, 101, 202) for use in such a system (200) and a method (400) using the system (200).

The disclosure relates to a method for H.sub.2 sensing in a gas stream utilizing a hydrogen sensing material. The hydrogen sensing material is comprised of Pd-based or Pt-based nanoparticles having an average nanoparticle diameter of less than about 100 nanometers dispersed in an inert matrix having a bandgap greater than or equal to 5 eV, and an oxygen ion conductivity less than approximately 10.sup.7 S/cm at a temperature of 700 C. Exemplary inert matrix materials include SiO.sub.2, Al.sub.2O.sub.3, and Si.sub.3N.sub.4 as well as modifications to modify the effective refractive indices through combinations and/or doping of such materials. Additional exemplary matrix materials consist of zeolitic and zeolite-derivative structures which are microporous and/or nanoporous such as the alumino-silicates and the dealuminated zeolite NaA structures. Additional sensing layers may be comprised of (1) a single nanocomposite layer comprised of Pd- or Pt-based particles dispersed within an inert matrix, (2) multi-layered sensing layers comprised of a nanocomposite layer with a filter overlayer, (3) core-shell layers comprised of matrix materials surrounding a core of Pd-based or Pt-based nanoparticles, and any combinations of the above.

Some embodiments of the present disclosure provide an optical sensor. The optical sensor includes a semiconductive block having a front side and a back side, a wave guide region, and a light sensing region. The wave guide region is positioned over the back side of the semiconductive block and having a core layer. The wave guide region is configured to guide an incident light. The light sensing region is positioned in the semiconductive block, having a multi-junction photodiode. The light sensing region is configured to sense emission lights from the wave guide region.

The present disclosure relates to optical fiber-based devices, and more particularly to light-absorbing optical fiber-based systems and methods.

The present invention relates to an optical fibre for use in a system for detection of one or more compounds in a fluid. The optical fibre (100, 101, 202) comprising at least two binding portions (102, 104, 118, 210, 211, 212) separated from each other along the longitudinal direction (106) of the optical fibre (100, 101, 202), wherein each of the at least two binding portions (102, 104, 118, 210, 211, 212) comprises a plasmonic structure (120) and/or a SERS structure (121), and a binding material (126) for binding of one or more compounds, wherein at least two binding portions (102, 104, 118, 210, 211, 212) are arranged for binding the same compound or compounds, wherein the optical fibre (100, 101, 202) is arranged for receiving light and transmitting light to each of the at least two binding portions, wherein each of the at least two binding portions (102, 104, 118, 210, 211, 212) is arranged such that light transmitted through that binding portion (102, 104, 118, 210, 211, 212) without bound compound is different compared to light transmitted through that binding portion (102, 104, 118, 210, 211, 212) with bound compound, or light reflected back from that binding portion (102, 104, 118, 210, 211, 212) without bound compound is different compared to light reflected back from that binding portion (102, 104, 118, 210, 211, 212) with bound compound. The present invention further relates to a system (200) for detection of one or more compounds in a fluid (103) and an optical fibre (100, 101, 202) for use in such a system (200) and a method (400) using the system (200).

The present invention relates to a reusable optical fiber aptasensor using a photo-thermal effect, and more particularly, to a reusable optical fiber aptasensor using white light and a laser. The aptasensor includes a light emitting unit for selectively emitting one of white light and a laser, a sensor unit including a plurality of aptamers, a plurality of gold nanorods, and a silver mirror, a detector for analyzing a wavelength of inputted light, and an optical fiber for connecting the light emitting unit with the sensor unit, and connecting the detector with the sensor unit, wherein the light emitted from the light emitting unit is totally reflected in the optical fiber and irradiated to the sensor unit, and light reflected from the silver mirror of the sensor unit is irradiated to the detector. Accordingly, the aptasensor easily measures concentration of a target material in a sample using the optical fiber.

Disclosed is a design for distributed optic fiber sensors and a corresponding method for sensing chemical concentrations with distributed fiber optic sensors, which utilizes segments of optical fiber which incorporate multiple sensing locations along the fiber. The distributed sensors incorporated into the optic fiber generate signals which are simultaneously detected and combined to produce a resultant signal with the effective optic fiber sensor length equal to that of the corresponding fiber segment.

A multi-path interferometric sensor for sensing small changes in the refractive index of sensing arms thereof, such as caused by the presence of an analyte or changes in analyte concentration, is disclosed. The sensor includes a single light source, a single detector, and a plurality of interferometers or a single multi-path interferometer. The various sensing branches within the multi-path interferometric sensor each include a delay having a different length. This results in a different modulation frequency for each interferometer, each of carriers include phase information that correlates to a change in refractive index and, ultimately, analyte concentration. The plural carrier frequencies enable simultaneous detection of multiple samples.

The present disclosure relates to structures, systems, and methods for characterizing one or more fluorescent particles. At least one embodiment relates to an integrated waveguide structure. The integrated waveguide structure includes a substrate. The integrated waveguide structure also includes a waveguide layer arranged on top of the substrate. The waveguide layer includes one or more excitation waveguides, one or more emission waveguides, and a particle radiation coupler, which includes a resonator element. In addition, the integrated waveguide structure includes one or more sensing sites configured with respect to the one or more excitation waveguides and the one or more emission waveguides such that a fluorescent particle at one of the sensing sites is activated by an excitation radiation transmitted via the one or more excitation waveguides and radiation emitted by the fluorescent particle is coupled into at least one of the emission waveguides by the particle radiation coupler.

A method is described of manufacturing an optical sensing element for detecting a presence and/or determining a concentration of an analyte in a fluid medium, in particular in an aqueous medium. The optical sensing element includes an optical waveguide (e.g. an optical fiber) comprising an optically transparent material for guiding light through the sensing element along a flightpath. The optical sensing element further includes an inorganic coating for adsorbing the analyte from the fluid medium and an adhesion promotion layer formed between the optical waveguide and the inorganic coating. The adhesion promotion layer includes an adhesion promotion material for promoting adhesion of the inorganic material.