Abstract: A method for forming an optical fiber having at least one of a microresonator and a coupler integrated therein is described. The method includes providing an optical fiber having a light guiding core. modifying at least one region of the optical fiber using a laser, immersing the optical fiber having the at least one region as modified inside an etchant that selectively etches the at least one region as modified to generate at least one of a microresonator and a coupler integrated in the optical fiber, and removing the optical fiber from the etchant. The optical fiber as removed from the etchant may include the at least one of the microresonator and the coupler. The method may further include heating the optical fiber using, for example, a CO2 laser or other heating apparatus, to smoothen surface irregularities of at least one of the microresonator and the coupler.

Abstract: Aspects of triboelectric fibers and methods of manufacture of the fibers are described. In one example, a method of manufacture of a fiber for generating energy using the triboelectric effect includes forming a preform tube, heating the preform tube in a furnace, feeding a wire through the preform tube and the furnace during the heating, and pulling the wire through the furnace to form a fiber. The methods described herein can be relied upon to manufacture fibers long enough for industrial-scale textile manufacturing, including for use with industrial-scale looms. In one example, forming the preform tube can include providing a polypropylene tube and wrapping the polypropylene tube with a housing layer of amorphous film, such as acrylic film. The acrylic film can be relied upon to maintain the form and integrity of the polypropylene as the wire is pulled, and the acrylic film can be easily removed after the pulling.

Abstract: A thermal measurement system enables high-resolution sub-surface temperature monitoring during additive manufacturing processes through machine learning demodulation of chirped fiber Bragg grating (C-FBG) sensors. An optical sensing subsystem includes a C-FBG sensor that encodes spatial temperature information in wavelength for high-temperature operation. A neural network model transforms complex reflection spectra into spatial temperature profiles with micrometer-scale resolution, overcoming limitations of traditional demodulation methods. A calibration subsystem generates synchronized spectral and thermal imaging data for training the neural network using controlled thermal profiles. The system captures steep thermal gradients and rapid cooling rates during laser powder bed fusion operations. A fiber embedding technique maintains the sensor in a strain-free condition at controlled sub-surface depths.

Abstract: Flexible and scalable miniature capacitive and inductive strain sensors, as well as methods for fabricating such strain sensors are described herein. According to an example, a flexible capacitive strain sensor can include a stretchable center core and two parallel wires wound about the stretchable center core, forming a double helix structure. Each of the two parallel wires can be embodied as an insulated or an uninsulated copper wire and the stretchable center core can be embodied as a polyester elastic string. The two parallel wires can be wrapped around the stretchable center core in a gapless fashion and with a winding angle of less than 45 degrees with respect to the stretchable center core.

Abstract: A method for forming an optical fiber having at least one of a microresonator and a coupler integrated therein is described. The method includes providing an optical fiber having a light guiding core. modifying at least one region of the optical fiber using a laser, immersing the optical fiber having the at least one region as modified inside an etchant that selectively etches the at least one region as modified to generate at least one of a microresonator and a coupler integrated in the optical fiber, and removing the optical fiber from the etchant. The optical fiber as removed from the etchant may include the at least one of the microresonator and the coupler. The method may further include heating the optical fiber using, for example, a CO2 laser or other heating apparatus, to smoothen surface irregularities of at least one of the microresonator and the coupler.

Abstract: 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.

Abstract: Aspects of triboelectric fibers and methods of manufacture of the fibers are described. In one example, a method of manufacture of a fiber for generating energy using the triboelectric effect includes forming a preform tube, heating the preform tube in a furnace, feeding a wire through the preform tube and the furnace during the heating, and pulling the wire through the furnace to form a fiber. The methods described herein can be relied upon to manufacture fibers long enough for industrial-scale textile manufacturing, including for use with industrial-scale looms. In one example, forming the preform tube can include providing a polypropylene tube and wrapping the polypropylene tube with a housing layer of amorphous film, such as acrylic film. The acrylic film can be relied upon to maintain the form and integrity of the polypropylene as the wire is pulled, and the acrylic film can be easily removed after the pulling.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.