119 results about "Fibre optic sensors" patented technology

This invention provides a method for controlling production operations using fiber optic devices. An optical fiber carrying fiber-optic sensors is deployed downhole to provide information about downhole conditions. Parameters related to the chemicals being used for surface treatments are measured in real time and on-line, and these measured parameters are used to control the dosage of chemicals into the surface treatment system. The information is also used to control downhole devices that may be a packer, choke, sliding sleeve, perforating device, flow control valve, completion device, an anchor or any other device. Provision is also made for control of secondary recovery operations online using the downhole sensors to monitor the reservoir conditions. The present invention also provides a method of generating motive power in a wellbore utilizing optical energy. This can be done directly or indirectly, e.g., by first producing electrical energy that is then converted to another form of energy.

A fiber optic sensor has a hollow tube bonded to the endface of an optical fiber, and a diaphragm bonded to the hollow tube. The fiber endface and diaphragm comprise an etalon cavity. The length of the etalon cavity changes when applied pressure or acceleration flexes the diaphragm. The entire structure can be made of fused silica. The fiber, tube, and diaphragm can be bonded with a fusion splice. The present sensor is particularly well suited for measuring pressure or acceleration in high temperature, high pressure and corrosive environments (e.g., oil well downholes and jet engines). The present sensors are also suitable for use in biological and medical applications.

Methods for calibrating and making measurements using fiber optic sensors are disclosed using backscattered wavelengths and independent sensors. The disclosure sets outs methods applicable with fiber optic sensors either in a deployed in a loop and in a linear configuration and useful for measurements including temperature.

A fiber optic sensor is provided. The fiber optic sensor includes a fiber core having a plurality of grating elements wherein, the grating elements comprise a periodic or a quasiperiodic modulated microcrystalline and silicon dioxide tetrahedral structure and a cladding disposed about the fiber core.

A method 2 of determining the location of deposits in a flowline comprises providing 4 a distributed vibration sensor along the flowline, measuring 6 vibrations along the flowline with the sensor and analysing 8 the measured vibrations to determine the location of any deposits. The vibration measurements are made using a distributed fibre optic sensor provided on the flowline. The measurements are analysed in real time to identify deposit formation and location within the flowline.

A method and an apparatus are disclosed for the measurement of the aridity, temperature, flow rate, total pressure, still pressure, and kinetic pressure of steam at a downhole location within a well through which wet steam is flowing. The apparatus comprises a series of fiber optic sensors that are mounted on sections of a shell assembly. The apparatus is lowered into a well to different downhole locations, and measures the multiple parameters of steam at different locations and heights. The data can be stored on board for subsequent analysis at the surface when the apparatus is retrieved from the well. The apparatus is very reliable, accurate, and of long-life in harsh environments.

The invention discloses a polarization maintaining optical fiber with a small bending radius and a manufacture method of the polarization maintaining optical fiber and relates to the field of optical fiber manufacture. The polarization maintaining optical fiber comprises a silica cladding, a core layer, a second silica cladding ring, a third fluorine-doped silica cladding ring and two stress cat eyes are sequentially arranged in the silica cladding from inside to outside, and the two stress cat eyes are in central symmetry with the core layer. By means of the manufacture method, the bending radius of the manufactured polarization maintaining optical fiber is smaller than 5mm, operating wavelength of the polarization maintaining optical fiber is 1550nm, and supplementary deterioration of the polarization maintaining optical fiber is under 0.4dB / km. According to the polarization maintaining optical fiber, under the condition that the bending radius is small, low-loss information transmission of the polarization maintaining optical fiber is achieved, low supplementary deterioration and good crosstalk characteristics of the polarization maintaining optical fiber are guaranteed, fiber optic sensors with small sizes can be manufactured by means of the polarization maintaining optical fiber, and requirements of users are satisfied.

A fiber-optic sensor can have a Michelson sensor portion and a Mach-Zehnder sensor portion. A first splitter-coupler can be configured to split incoming light between a first fiber portion and a second fiber portion. A first polarization-phase conjugation device can be configured to conjugate a polarization phase of incident light corresponding to the first fiber portion, and a second polarization-phase conjugation device can be configured to conjugate a polarization phase of incident light corresponding to the second fiber portion. Each of the first and second polarization-phase conjugation devices can be configured to reflect light toward a detector and through the respective first and second fiber portions. A coupler can be configured to join light in the first fiber portion with light in the second fiber portion, and a third fiber portion can be configured to receive light from the coupler and to illuminate a second detector.

The invention provides a phase generator carrier (PGC) digital demodulation method for an interferometric fiber optic sensor and a device thereof. The PGC digital demodulation method for the interferometric fiber optic sensor comprises the following steps: outputting interference light intensity signals including sensing signals phi(t), and carrier signals by adopting the PGC technique; performing discrete sampling on the interference light intensity signals in the whole observation time T to obtain time domain sequence signals of the interference light intensity signals; by taking a carrier fundamental frequency cycle Tc as a unit, dividing the T into a plurality of time slots, and performing discrete Fourier transformation (DFT) on the time domain sequence signals in all the slots Tc to obtain the frequency spectrums of the time domain sequence signals; performing inverse discrete Fourier transformation (IDFT) on the frequency spectrums to reconstruct corresponding time domain signals; and according to the relation between the harmonic amplitudes of the reconstructed signals and the harmonic amplitudes of continuous signals, calculating the in-phase components cosphi(t) and the quadrature components sinphi(t) of the sensing signals phi(t) in all carrier cycles Tc, and performing the calculation slot by slot until the cosphi(t), sinphi(t) and the sensing signals phi(t) in the whole observation time T are obtained, and signal PGC demodulation is realized by the digital technology. A mixing system is not adopted, a local oscillation signal is not needed, and the problems, such as carrier signal synchronization and the like do not exist, and the overall performance is better.

The general field of the invention is that of fiber-optic sensors comprising at least one measurement optical fiber having an optically pumped doped amplifying medium, the optical characteristics of which are sensitive to a physical quantity, the fiber having at least one Bragg grating. The fiber is designed so as to generate, in the amplifying medium, two optical waves having different optical frequencies that propagate in the same direction after reflection on the Bragg grating and are emitted by the amplifying medium, the two optical frequencies depending on the physical quantity. The two waves may be generated using either a birefringent polarization-maintaining fiber or a DBR (Distributed Bragg Reflector) laser cavity. Notably, this sensor may be used as a hydrophone.

The invention relates to a mobile phone audio interface-based visible light close communication system and method. The system comprises a transmitting terminal of a mobile phone with an external LED (light emitting diode) module and an installed encoding module, and a receiving terminal with a light ray sensor, a decoding module and application software, wherein the LED module is connected to the audio interface of the smart mobile phone; the encoding module packages and encodes original data, modulates an audio signal by using the encoded data and transmits to the LED module, and the audio signal is changed into a visible light signal to be sent; the light ray sensor receives the visible light signal and transforms the visible light signal into an electric signal, and data packets are acquired by decoding via the decoding module; whether data in each data packet can pass CRC (cyclic redundancy check) or not is judged, and if so, the decoded data are transmitted to the application software to be processed. Transforming hardware of mobile equipment is not needed, visible light close communication can be realized by the external LED module, and the system and the method can be widely applied in near field communication application scenes such as mobile payment, equipment pairing and data exchange between mobile phone users.

Fiber optic sensors employ a high brightness light source such as a fiber optic supercontinuum source, multiplexed superluminescent light emitting diodes, or a broadband tunable laser diode. Light is delivered to the measurement location via fiber optics and sensor optics directs infrared radiation onto material the being monitored that is located in a hostile environment. A disperse element is positioned in the detection beam path in order to separate the wavelengths and to perform spectral analysis. A spectral analysis of the radiation that emerges from the sheet yields information on a plurality of parameters for the material. For papermaking applications, the moisture level, temperature and cellulose content in the paper can be obtained.

A fiber optic sensor includes at least two Fabry-Perot (FP cavities) defined by at least three partially reflecting surfaces which individually and together are capable of generating different interference spectra which are affected by temperature. One of the FP cavities is formed at an end of the sensor and includes a surface which is capable of supporting a thin film, the optical thickness of which is to be measured. The other FP cavity between the lead-in fiber and the first FP cavity thus does not include the film and can thus independently provide highly accurate temperature information for calibrating the optical length of the second FP cavity and compensation for temperature effects on measurement of the thin film supported thereon, preferably by subtraction of a calibrated temperature-dependent change in optical length of the second FP cavity from the measurement made.

In order to solve the problem of low sensitivity of existing fiber optic SPR biosensors, the invention provides a sensitized fiber optic SPR sensor based on graphene oxide and gold nanorods. Accordingto the sensitized fiber optic SPR sensor based on the graphene oxide and the gold nanorods, the plasmon coupling effect between a plasma wave on the surface of a gold film and a local surface plasmawave on the surface of the gold nanorods is utilized to enhance the electric field strength. At the same time, the charge transfer between the gold film and the gold nanorods can be promoted by the graphene oxide, so that interactions between a surface plasma wave and a substance to be detected is enhanced, and the detection sensitivity is improved. In addition, the graphene oxide has excellent bio-sensing characteristics, biocompatibility, and a large specific surface area, can better measure biomass and chemical quantities. Compared to an ordinary fiber optic SPR sensor, the sensitized fiberoptic SPR sensor based on the graphene oxide and the gold nanorods has higher sensing sensitivity and chemical stability, real-time monitoring can be performed, the structure of the sensor is compact, thereby being able to widely applied in the fields of physics, chemistry, biology, medical care, food safety and the like.

Exemplary practice of the present invention provides an air vehicle and at least one interferometric double-path fiber optic sensor connected with the air vehicle. Each fiber optic sensor includes a pair of optical fibers, viz., an optical sensing fiber and an optical reference fiber, in a parallel and propinquus relationship. The paired optical fibers of each fiber optic sensor are attached to the air vehicle either (i) circumferentially around the fuselage or (ii) lengthwise along the fuselage or (iii) span-wise along the wings and across the fuselage, and are configured whereby the sensing fiber is exposed to the atmosphere and the reference fiber is not. Each fiber optic sensor senses atmospheric infrasound but does not sense atmospheric wind noise, which is negated by incoherency associated with design lengthiness of the optical fiber pair. Noise and strain due to temperature, vibration, and propulsion are neutralized via interferometric common mode rejection.

A fiber optic sensing system. The fiber optic sensing includes an optical source and a lead cable for receiving an optical signal from the optical source. The fiber optic sensing system also includes a sensor array for receiving the optical signal from the lead cable. The sensor array includes a plurality of fiber optic sensors, each of the plurality of fiber optic sensors including an interferometer having two legs. The plurality of fiber optic sensors includes a noise compensation sensor. Each of the legs of the interferometer of the noise compensation sensor is configured to sense vibration in substantially the same manner.

The invention relates to a dual-channel optical fiber SPR sensor. The dual-channel SPR sensor comprises a reference channel and a sensing channel; the reference channel serves as a blank control reference channel and detects a wavelength shift quantity caused by non-specific adsorption; and the sensing channel improves the detection sensitivity of the sensor by enhancing the intensity of a local electric field through utilizing a coupling effect between a gold film and gold nanoparticles, and improves the immobilization efficiency of an antibody by utilizing a graphene oxide thin film. The twochannels in the dual-channel optical fiber SPR sensor use different metal films respectively, so that two resonance valleys are generated, double-channel sensing is realized, and the unique advantages of eliminating a measuring error caused by the non-specific adsorption and being insensitive to the temperature are achieved; and the two SPR resonance valleys of the two channels are separated fromeach other, so that the SPR resonance valleys are prevented from generating the adverse effects mutually in the detection process, and biological sensing is better facilitated. According to the sensor, the problems that the sensor is low in sensitivity and easy to influence by liquid refractive index change and temperature fluctuation in the prior art are effectively solved.

In an embodiment according to the present invention, a coronagraph for detecting reflective bodies external to a light source is provided. A first mirror for directing a beam of light onto an occulting mask is adjusted based on a data from a fiber optic sensor or a second sensor. An occulting mask for separating the beam into a first and second portion directs the first portion onto a fiber optic sensor and the second portion onto a Lyot stop. The occulting mask is adjustable based on data from the second sensor. The Lyot stop separates the second portion of the beam into a third and fourth portion. The Lyot stop also directs the third portion of the beam onto the second sensor and the fourth portion of the beam onto a camera for detecting one or more reflective bodies external to a light source.

The invention discloses automatic lead seal feeding equipment for an intelligent ammeter and a work method adopting the automatic lead seal feeding equipment. The automatic lead seal feeding equipmentfor the intelligent ammeter comprises a vibrating material disc, a conveying table, a lead seal feeding device, a lead seal pressing device, stop devices, optical cable sensors used for detecting theintelligent ammeter and a controller. A discharging opening of the vibrating material disc is connected with a conveying groove. A conveying belt used for conveying the intelligent ammeter is arranged on the conveying table. The lead seal feeding device and the lead seal pressing device are sequentially arranged on the conveying table in the conveying direction of the intelligent ammeter. The stop devices are arranged at the positions, corresponding to the lead seal feeding device and the lead seal pressing device, of the conveying table. The corresponding optical cable sensor is arranged atthe position, corresponding to each stop device, of the conveying table. The optical cable sensors are connected with the signal input end of the controller. The signal input end of the lead seal feeding device and the signal input end of the lead seal pressing device are connected with the signal output end of the controller. The automatic lead seal feeding equipment is high in automation degree,reasonable in design and high in efficiency, and manpower and material resources are saved.

An on-line detection method and an on-line detection system for the supernatant liquid height of a settling tank for liquid-solid separation belong to the interdisciplinary field of mechanics, microelectronics, measurement and the like. The system comprises a PLC (Programmable Logic Controller) control system, an industrial computer, a printer, a windlass, a rotary encoder, a fiber optic sensor and a rotary washing tank; the PLC control system drives the windlass to send the fiber optic sensor into the settling tank; the fiber optic sensor feeds back an outputted direct-current voltage value to the PLC control system in real time; according to whether the direct-current voltage value abruptly drops or not, the PLC control system controls the windlass, and acquires the output value of the rotary encoder in real time to judge the dropping depth of the fiber optic sensor; after measurement is finished, the PLC control system drives the windlass to lift the fiber optic sensor out of the settling tank, and controls the rotary washing tank to wash the fiber optic sensor, cleaning off scale. The invention has the advantages of high measurement precision, high detection speed, convenience in maintenance, continuous detection and full-automatic real-time control.

Refractive index modifications such as e.g. Fiber Bragg gratings in micro-structured Fiber are according to an aspect of the invention fabricated by first filling and / or purging the holes of the micro-structured fiber with inert gas or by evacuation and, optionally subsequently scaling the ends. Alternatively, the ends of the micro-structured fiber may be sealed without a preceding purging or evacuation of the holes. In this way hydrogen or deuterium present in the holes after photosensitizing loading will not react with atmospheric oxygen to form water. Water formed this way would otherwise seriously impair the grating formation process. Bragg gratings and other refractive index structures can thus be fabricated with high quality and predictable specifications in micro-structured fiber. Sealing the fiber ends also prevents in-diffusion of moisture. The invention may e.g. find application in connection with fiber optical sensors, high-power fiber lasers, etc.

A method for performing a rapid, homogenous assays for monitoring the reactions of a binding target, by immobilizing a fluorescent-capable chelate complex that is derivatized so as to posses recognition binding ligands, labeling the complex with a labeled second chelator that is added to the assay thereby forming a fluorescent mixed chelate, and measuring the fluorescent mixed chelate, whereby the measurement of the label enable monitoring of the reaction of the binding target. A rapid assay for performing the above method including a first chelating molecule, a fluorescent-capable ion complexed with the first chelating molecule, a second chelating molecule for reacting with the fluorescent-capable ion complexed with the first chelating molecule, and a measuring device for measuring fluorescent resulting from the second is chelating molecule reacting with the fluorescent-capable ion complexed with the first chelating molecule. A biosensor for monitoring molecular interactions between receptors, including a biosensor having attached thereto a fluorescent-capable ion complexed with a first chelating molecule, whereby upon exposure to a second chelating molecule said complex becomes fluorescent is also provided.

The invention provides a low resonance eccentric fiber optic acoustic sensor based on F-P interference. The device comprises the following contents that the laser emitted by a tunable laser is dividedinto two paths after passing through a fiber optic coupler, one path is directly collected as reference light and the other path enters an eccentric fiber optic acoustic sensor head through a fiber optic circulator and a single-mode fiber optic to eccentric fiber optic module, and the reflected light enters the other photoelectric conversion module through the fiber optic circulator. The eccentric fiber optic acoustic sensor head coats a transparent organic molecular film and two metal films on the eccentric fiber optic end surface by a coating technology to form an F-P resonant cavity, and the F-P interference generated at the front end of the fiber optic through by the light can be used to convert the sound signal into a modulated optical signal. After passing through the photoelectricconversion module and the amplification module, the signal is collected and processed to restore the acoustic signal at the fiber optic end. The design of the eccentric fiber optic greatly reduces resonance and residual vibration noises. The low resonance eccentric fiber optic acoustic sensor based on F-P interference provided by the invention has the advantages of simple structure, good reliability, higher sensitivity and signal-to-noise ratio than the traditional fiber optic sensor, and has wide application prospects.