The present invention relates to a sensor using a tilted fiber grating to detect physical manifestations occurring in a medium. Such physical manifestations induce measurable changes in the optical property of the tilted fiber grating. The sensor comprises a sensing surface which is to be exposed to the medium, an optical pathway and a tilted grating in the optical pathway. The grating is responsive to electromagnetic radiation propagating in the optical pathway to generate a response conveying information on the physical manifestation.

Embodiments of the present invention include a cuvette (100) for use in determining a refractive index of a sample matter in a spectrophotometer (600), the cuvette comprising a container (102) for holding the sample matter, the container (102) having an entry window (121) that allows input radiation to reach the sample matter, the container furthermore having an exit window (122) that allows a part of the input radiation to exit the container part, the entry window and the exit window defining a radiation path; and comprising a photonic crystal (101) rigidly attached to the container or integrally formed in the container and arranged in the radiation path, the photonic crystal having a grating part (111) causing a reflectance spectrum of the photonic crystal to exhibit a resonance. A spectrophotometer is also provided.

A device for determining a refractive index may be provided. The device including at least one waveguide having a core and a cladding surrounding the core, the cladding being at least partly removed in at least one first longitudinal portion and the core including at least one fiber Bragg grating in at least one second longitudinal portion. A method for determining a refractive index or a pressure change in a fluid may also provided. The method may include at least one waveguide having a core and a cladding surrounding the core, the cladding being at least partly removed in at least one longitudinal portion. A method for producing such a device may also be provided.

A device for use in the detection of binding affinities, the device comprising a planar waveguide (2) arranged on a substrate (3), and further comprising an optical coupler (41) having a predetermined length for coupling coherent light (1) of a predetermined wavelength into the planar waveguide (2) such that a parallel beam of coherent light propagates through the planar waveguide (2) with an evanescent field (11) of the coherent light propagating along an outer surface (21) of the planar waveguide (2). The outer surface (21) of the planar waveguide (2) comprises binding sites thereon capable of binding target samples to the binding sites such that light of the evanescent field (11) is diffracted by target samples bound to the binding sites. The binding sites are arranged along a plurality of predetermined straight lines (7) running parallel to one another with a constant distance between adjacent straight lines.

Optical sensors having one or more soluble coatings thereon are used to detect the presence of a degrading fluid. In a generalized embodiment, the fiber optic sensor includes a fiber optic cable having two strain sensor positioned therein. A soluble layer is positioned over one of the strain sensor. Due to the presence of the soluble layer, the covered strain sensor optically responds differently than the other strain sensor to changes in pressure, strain and temperature. In the presence of a degrading fluid, the soluble layer degrades and ultimately dissolves, thereby changing the optical response of the previously covered strain sensor. When the soluble layer is dissolved, the strain induced by the soluble layer relaxes, thus causing a wavelength shift in the signal of the grating. By monitoring the wavelength shifts of both strain sensors, the fiber optic sensor acts as a detector for the presence of the degrading fluid.

The invention relates to the field of surface waves based optical devices particularly tuneable optical filter, optical biosensors and spatial light modulators. An optical sensor and tuneable filter is disclosed based on high contrast periodic structures deposited on a substrate and using a compact reading method for low detection limit using a one dimensionally diverging quasi-monochromatic beam and a camera.

A system for determining a process variable of a medium arranged in a container is disclosed, including an optical fiber Bragg sensor with an optical waveguide with a fiber Bragg grating, a signal generating unit designed to generate an optical input signal and couple it into the waveguide, a receiving unit designed to receive an optical output signal from the waveguide and converts it into an electrical output signal, and an evaluating unit which determines the process variable using the electrical output signal, wherein a subsection of the optical waveguide is arranged inside or in a wall of the container, the subsection designed such that the fiber Bragg grating is affected by the process variable to be determined of the medium.

An optical sensor device includes an optical waveguide portion having a core, the core having a first refractive index, and a functional material layer coupled to the optical fiber portion, the functional material layer being made of a metal oxide material, the functional material layer being structured to have a second refractive index, the second refractive index being less than the first refractive index. The functional material layer may be a nanostructure material comprising the metal oxide material with a plurality of holes or voids formed therein such that the functional material layer is caused to have the second refractive index.

A scour monitoring system may provide a housing that is separated into multiple segments that are fluidically isolated from each other. The scour monitoring system may be position adjacent to a structure to be monitored for bridge scouring. Each of the segments may provide a water-swellable material positioned near or in contact with a fiber Bragg grating (FBG) cable. If water penetrates a segment, the water-swellable material may expand to deform the FBG cable. The wavelength of the FBG cable may be monitored periodically for changes, thereby providing moisture detection when a change in wavelength is detected.

A system for use with a randomly dispersed chiral organic solution. The system includes: an infrared laser that outputs a light beam having a wavelength in an IR spectrum; a stage that holds the randomly dispersed chiral organic solution, the stage being arranged to receive the light beam from the infrared laser, the stage including a silicon-on-insulator (SOI) resonating cavity structure configured to generate chiral signals in a linear IR regime, the stage being configured to generate a second harmonic optical signal from the light beam, the second harmonic optical signal being in an ultraviolet (UV) spectrum, the stage being configured to output the second harmonic optical signal; a UV detector that can receive the second harmonic optical signal from the stage; and an analyzer being configured to determine a chiroptical signature for the randomly dispersed chiral organic solution based on the received second harmonic optical signal.