Virginia Tech Intellectual Properties, Inc.

Sentek Instrument LLC

Center for Innovative Technology

Virginia Polytechnic Institute and State University

Senek Instrument LLC

Anbo Wang

Bo Dong

Gary R Pickrell

Daniel Kominsky

Ahmad Safaai-Jazi

Roger Stolen

Jeong I Kim

Kent A Murphy

Richard O Claus

Fabin Shen

Yizheng Zhu

Juncheng Xu

Jun Wang

Ashish M Vengsarkar

Xiaoting Jia

Wei Peng

Bing Qi

Yuhong Duan

Wei Zhao

Jianmin Gong

Hai Xiao

Shari Feth

Yan Zhang

Sridhar Gollapudi

Kristie L Cooper

Haifeng Xuan

Lingmei Ma

Li Yu

Xingwei Wang

In one aspect, the disclosure relates to multi-material fibers capable of distributedly measuring temperature and pressure in which the methods comprise a thermal drawing step, and the methods of fabricating the disclosed fibers. The fibers can be utilized in methods of temperature and pressure mapping or sensing comprising electrical reflectometry for interrogation. Further disclosed are devices comprising a disclosed fiber with the multi-point detection capability with simple one-end connection. Also disclosed are articles, e.g., smart clothing, wound dressing, robotic skin and other industrial products, comprising a disclosed fiber or a fabric comprising a disclosed fiber. This abstract is intended as a scanning tool for purposes of searching in the particular art and is not intended to be limiting of the present disclosure.

Methods and systems for distributed temperature and pressure sensing comprising a polymer fiber

A system for measuring pressure, temperature or both includes a diaphragm that responds to a change in temperature or pressure, and a base connected to the diaphragm that has a sapphire element. Between the diaphragm and the base is a cavity. An optical fiber that conducts light reflected off of a surface of the diaphragm is adjacent the cavity. An interrogator is used for detecting a deflection of the diaphragm based on at least two reflected light signals having similar wavelengths and coherence lengths. A quadrature phase detection unit demodulates signals received by the interrogator.

Sapphire sensor for measuring pressure and temperature with improved stress and temperature variation compensation

Forming a light pulse having a plurality of time-dependent frequency components such as a chirped light pulse or a light pulse group and superposing reflected light from different portions of an optical fiber allows detection of changes in effective optical path differences due to physical parameters in the environment of the optical fiber by sensing the optical interference pattern of each light frequency and wavelength. The development of a plurality of interference patterns from each light pulse provides sufficient information for robust demodulation by known methods to produce signals having good fidelity to variations in the physical parameters of interest, particularly vibrations and acoustic waves. The location of the measured physical parameter along the optical fiber can be determined from the time difference between injecting the light pulse and detection of a reflection or Rayleigh backscattering and diffraction index of the optical fiber.

Method and apparatus for distributed sensing

A sensor apparatus and system for measuring pressure, temperature or both with a single interrogator includes a sensor having a cavity, a diaphragm and an optical element or base for conducting energy to and from the cavity and diaphragm. The two surfaces of the diaphragm and a surface of optical element and either surface of the diaphragm are partially reflecting surfaces and respectively define two optical path distances (OPDs) that produce preferential reflections and interference patterns at different optical frequencies or wavelengths that are respectively affected by pressure or temperature. Arranging the OPDs such that the fundamental frequency and harmonics of preferential reflections one OPD do not coincide with the fundamental frequency or harmonics of another OPD provides for both temperature and pressure measurement with a single interrogator and without complex spectral analysis.

Sapphire sensor apparatus including an optical fiber for measuring pressure and temperature

Method for creating an optical sensing fiber having a reflective structure integrally disposed therein, comprising: providing an optical fiber having a core and a cladding layer disposed in optical contact with the core, and having a polymer coating layer disposed in contact with and surrounding the cladding layer, the coating layer at least partially transparent in the wavelengths of 390-600 nm; providing a source of electromagnetic radiation having a wavelength in the range of 390-600 nm; and delivering a selected wavelength of the electromagnetic radiation through the coating layer to a selected location within the fiber core or cladding such that the delivered electromagnetic radiation alters the core or cladding to create at least one reflective structure in the core or cladding at the selected location.

Optical sensing fiber

A serial weak FBG interrogator is disclosed. The serial weak FBG interrogator may include a CW tunable laser or pulsed laser utilized as a laser source and an EDFA. The serial weak FBG interrogator may also be an interrogation of a single sensor system by utilization of a DFB laser which utilizes a single sensor, which may be an interferometer sensor, an extrinsic Fabry-Perot interferometer or a wavelength-modulated sensor. The serial weak FBG interrogator may also include a computer system or CSPU.

Serial weak FBG interrogator using pulses of differing wavelengths

A sensor for measuring pressure, temperature or both may be provided. The sensor may include a diaphragm that may respond to a change in temperature or pressure, a base connected to the diaphragm, a cavity, and an optical fiber that may conduct light reflected off of a surface of the diaphragm. The diaphragm and base may be sapphire elements. An interrogator may be provided for detecting a deflection of the diaphragm.

Sapphire sensor for measuring pressure and temperature

Serial fiber Bragg grating interrogator with a pulsed laser for reflection spectrum measurement

A random array of holes is created in an optical fiber by gas generated during fiber drawing. The gas forms bubbles which are drawn into long, microscopic holes. The gas is created by a gas generating material such as silicon nitride. Silicon nitride oxidizes to produce nitrogen oxides when heated. The gas generating material can alternatively be silicon carbide or other nitrides or carbides. The random holes can provide cladding for optical confinement when located around a fiber core. The random holes can also be present in the fiber core. The fibers can be made of silica. The present random hole fibers are particularly useful as pressure sensors since they experience a large wavelength dependant increase in optical loss when pressure or force is applied.

Holey optical fiber with random pattern of holes and method for making same

An inspection probe for directly measuring a transmission spectrum of a solvent oil in a transformer includes a tube having a plurality of apertures spaced along a side of the tube to allow oil to pass therethrough, and first and second optical collimators disposed at opposing ends of the tube. The first and second collimators are aligned by the tube such that incident light is transmitted through the first collimator, the tube, and the second collimator to a spectrometer.

Apparatus and method for on-line, real-time analysis of chemical gases dissolved in transformer oil

A method of coupling a silica fiber and a sapphire fiber includes providing a silica fiber having a doped core and a cladding layer, with the doped core having a prescribed diameter, providing a sapphire fiber having a diameter less than the doped core, placing an end of the sapphire fiber in close proximity to an end of the silica fiber, applying a heat source to the end of silica fiber and introducing the end of sapphire fiber into the heated doped core of the silica fiber to produce a coupling between the silica and sapphire fibers.

Fabrication of miniature fiber-optic temperature sensors

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.

Multi-cavity Fabry-Perot interferometric thin-film sensor with built-in temperature compensation

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Blacksburg, VA, United States of America

Anbo Wang