An apparatus for detecting one or more properties of a downhole fluid includes a housing. The apparatus also includes a location-sensitive optical detector, arranged within a chamber formed by the housing. The apparatus further includes a light source, arranged within the chamber. The apparatus also includes a lens, positioned at an end of the housing, the lens preferably having a flat side and a curved side, the flat side positioned proximate the chamber to position the flat side closer to the light source than the curved side. The apparatus further includes a mirror, arranged outside the housing.

A sensor for determining a liquid type, includes: a plano-convex lens; a lens holder configured to support the plano-convex lens via an edge of the lens; an outputting optical fiber that abuts against a plane surface of the plano-convex lens to output light; a light-receiving optical fiber that abuts against the plane surface of the plano-convex lens to receive light; a light-emitting unit connected to the outputting optical fiber; and a light amount measuring unit connected to the light-receiving optical fiber to measure a light amount. The outputting optical fiber is provided so that an end face of the outputting optical fiber is disposed on the edge of the plano-convex lens, and preferably, a central axis thereof at the end face thereof passes through the plane surface of the plano-convex lens.

The disclosure proposes a portable fiber optic measurement device (100) for physical, chemical, and biological sensing applications that facilitates real-time monitoring. The device (100) includes a fiber optic probe cartridge (120) that is removably attached to a measuring device (110). The device (110) includes a light source, a detector, and the associated electronic measurement and control unit along with a display. The device (100) is configured to measure the real-time changes in the light intensity on the fiber probe cartridge side (130). With a U-bent fiber optic probe cartridge (138) as an example, the device (100) is configured to measure the bulk solution refractive index changes, effective refractive index change, or characteristic optical property of analytes including ions, chemical and bio molecules, polymers, compounds, microorganisms present on the fiber core surface (138). The key facets of this device include high sensitivity, real-time and rapid analysis, handheld, and portable instrumentation at meager operational cost.

Embodiments of the invention comprise apparatus and methods for detecting the presence of a substance in a test material using a plurality of wavelength-specific couplers (e.g. tilted fibre gratings) which provide a spatially distributed multi-node all-optical measurement system. Each node of the measurement system can comprise an optical module that is sensitive to the intensity of a limited band of wavelengths. The node is thus capable of detecting the presence of an absorption peak in a spectrum without having to obtain the full spectrum. By providing a plurality of optical modules that are sensitive to different wavelengths, the spectral signature of different substances may be monitored without having to measure full spectra. The measurement system may be particularly useful in a process control environment where it is desirable to take measurements of one or more substances in different locations.

A device includes a substrate, a pedestal extending from the substrate, and a ring resonator disposed on the pedestal above the substrate. The ring resonator has a resonance wavelength greater than 1.5 μm and includes at least one of silicon and chalcogenide glass. The device can be used as a ring resonator sensor or a light source. The ring resonator is substantially transparent to mid-infrared radiation to reduce optical losses. The pedestal has a narrower width compared to the ring resonator to generate improved interaction between evanescent fields of light in the ring resonator and analytes nearby the ring resonator, thereby increasing sensing sensitivity. In addition, fabrication of the device is compatible with complementary metal-oxide-semiconductor (CMOS) processes and hence is amenable to large scale manufacturing.

An optical device configured to pass an input light signal through a medium under test, for example, a fluid, and to retrieve an output light signal. A comparison of the output light signal to the input light signal is indicative of the medium and can be used to determine if another unknown medium is the same. Another optical device passes an input signal through a known medium and an unknown medium and corresponding output light signals are received. A comparison of the output light signal corresponding to the unknown medium with the output light signal of the known medium can be used to characterize the unknown medium as against other mediums.

The present disclosure embodies a refractometer that includes an embodied fitting to the standardized probe with the optical structure to facilitate refractometer optics to the probe tip.

System and methods for sensing fluid characteristics of peritoneal dialysate infused into and removed from a patient during treatment are provided. The systems and methods can use an optical sensor including a transmitter light source operable to emit light through a fluid flow path and an optical receiver operable to receive at least a portion of the light emitted by the transmitter light source.

An apparatus for detecting one or more properties of a downhole fluid includes a housing. The apparatus also includes a location-sensitive optical detector, arranged within a chamber formed by the housing. The apparatus further includes a light source, arranged within the chamber. The apparatus also includes a lens, positioned at an end of the housing, the lens preferably having a flat side and a curved side, the flat side positioned proximate the chamber to position the flat side closer to the light source than the curved side. The apparatus further includes a mirror, arranged outside the housing.

A method for determining polymer concentration can include synthesizing a polymer in a reactor under a set of parameters, wherein the reactor comprises a solution mixture having a refractive index, and wherein the solution mixture comprises a solvent, a polymer, and optionally a monomer, wherein the solution mixture has a polymer concentration; measuring the refractive index of the solution mixture; comparing the refractive index of the solution mixture with a calibration curve; and identifying the polymer concentration in the solution mixture. A system for determining polymer concentration can include a reactor containing a solution mixture comprising a solvent, a polymer, and optionally a monomer; a flash vessel fluidly coupled to the reactor to receive the solution mixture from the reactor; and a first refractometer fluidly coupled to the reactor, placed between the reactor and the flash vessel, and configured to measure a refractive index of the solution mixture.