46 results about "Sapphire fiber" patented technology

In accordance with one exemplary embodiment the invention provides a multi-parameter fiber optic sensing system with an aperiodic sapphire fiber grating as sensing element for simultaneous temperature, strain, NOx, CO, O2 and H2 gas detection. The exemplary sensing system includes an aperiodic fiber grating with an alternative refractive index modulation for such multi-function sensing and determination. Fabrication of such quasiperiodic grating structures can be made with point-by-point UV laser inscribing, diamond saw micromachining, and phase mask-based coating and chemical etching methods. In the exemplary embodiment, simultaneous detections on multi-parameter can be distributed, but not limited, in gas / steam turbine exhaust, in combustion and compressor, and in coal fired boilers etc. Advantageously, the mapping of multiple parameters such as temperature, strain, and gas using sapphire aperiodic gratings improves control and optimization of such systems directed to improve efficiency and output and reduce emissions.

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.

In accordance with one exemplary embodiment the invention provides a multi-parameter fiber optic sensing system with an aperiodic sapphire fiber grating as sensing element for simultaneous temperature, strain, NOx, CO, O2 and H2 gas detection. The exemplary sensing system includes an aperiodic fiber grating with an alternative refractive index modulation for such multi-function sensing and determination. Fabrication of such quasiperiodic grating structures can be made with point-by-point UV laser inscribing, diamond saw micromachining, and phase mask-based coating and chemical etching methods. In the exemplary embodiment, simultaneous detections on multi-parameter can be distributed, but not limited, in gas / steam turbine exhaust, in combustion and compressor, and in coal fired boilers etc. Advantageously, the mapping of multiple parameters such as temperature, strain, and gas using sapphire aperiodic gratings improves control and optimization of such systems directed to improve efficiency and output and reduce emissions.

The invention discloses a U-shaped structure sapphire fiber grating temperature and stress sensor and a manufacturing method thereof. According to the U-shaped structure sapphire fiber grating temperature and stress sensor, the end face of a section of sapphire fiber is of a micropore structure, and a low-refractive-index cladding structure similar to photonic crystal fiber is formed; a section of long-period fiber grating enables MgO to be doped on the side face of the fiber by the adoption of an electromagnetic sputtering method so as to form MgAl2O4 crystals through reaction, the mechanical strength of the section of the fiber is changed, after grating is written into the fiber, two sections of grating are different in stress response, and the effect that temperature and stress are measured at the same time can be achieved. The U-shaped structure sapphire fiber grating temperature and stress sensor has the advantages of being simple in structure, wide in temperature measuring range, high in measuring accuracy and the like, and can be applied to temperature and stress measurement of rocket engines, optical cowlings and ultra-high temperature environments.

A method and apparatus for eliminating voids and improving crystal quality in shaped ceramic product, e.g. sapphire fiber or silicon sheet, from a melt by using a sloped die tip. The sloped die tip or array thereof comprises an outer sidewall which is sloped outwardly at an angle of 5° to 40° from the vertical.

The invention discloses a femtosecond laser etching based sapphire fiber Fabry-Perot sensor and a manufacturing method thereof. The sensor structure comprises a sapphire fiber (1), a quartz fiber (5)and a heterogeneous fiber fusion splice point (6) connecting the two fibers. The tail end of the sapphire fiber (1) has a Fabry-Perot microcavity (2) processed by femtosecond laser etching. Two reflected lights generated by a first reflecting surface (3) and a second reflecting surface (4) of the Fabry-Perot microcavity (2) interfere and generate an interference signal (11). When the ambient temperature changes, the cavity length of the Fabry-Perot microcavity (2) and the refractive index of a material change, and the optical path difference between the two reflected light changes accordingly,thus causing a change of the interference signal (11). The Fabry-Perot optical path difference is obtained by demodulating the interference signal, thereby obtaining a measured temperature. The invention has the characteristics of theoretical innovation, small size and strong environmental adaptability, which can be used for high temperature precision sensing in a narrow measurement environment.

A method for fabricating a sensor includes coating an end-polished sapphire fiber with aluminum to produce a sapphire fiber having an aluminum coating, anodizing the aluminum coating to produce an aluminum oxide coating, and removing the aluminum oxide coating from a distal end of the sapphire fiber.

The invention relates to a sapphire fiber-reinforced ceramic-matrix multi-phase composite as well as a preparation method and an application thereof. The preparation method comprises the steps as follows: a first component and a dispersing agent are mixed and are dried after being ball-milled under the protection of argon; the first component comprises iron oxide powder, aluminum powder and aluminum oxide powder; a dried product and a second component are evenly mixed, mixed powder is obtained, a sapphire fiber preform is arranged in the mixed powder, and hot-pressing sintering is performed under the vacuum condition; the second component comprises chromium powder; and a product obtained through hot-pressing sintering is pre-oxidized in the oxygen atmosphere, and the three-phase ceramic composite is obtained. With the three-phase ceramic composite, the mechanical strength of a heat shield prepared from the composite can be improved, the high-temperature resistance and the corrosion resistance of the heat shield can be improved, the service life can be prolonged, the thermal conductivity is reduced, and multi-cycle stable and reliable working can be realized at the high temperature of 1,900 K or above.

The invention provides a temperature detecting system and method based on a sapphire fiber grating sensor. The system of the invention comprises a broadband light source, a sapphire fiber grating sensor, a fiber circulator, a F-P filter, a photoelectric conversion module, an A / D conversion module, an acquisition control module, a D / A conversion module and a computer module. The method of the invention comprises the following steps: detecting reflected light wavelengths of the sapphire fiber grating sensor at each temperature by using a spectrometer; obtaining a fitting model of the reflected light wavelengths and the temperatures by a least square method; placing the sapphire fiber grating sensor on a target to be tested, and outputting a beam emitted by the broadband light source to the F-P filter through the fiber circulator; periodically changing the length of a F-P cavity according to a driving voltage digital signal sent by the acquisition control module; obtaining and storing themaximum value of the voltage of transmitted light of the F-P filter in the acquisition control module; and obtaining the temperature information according to the fitting model of the reflected lightwavelengths and the temperatures, and displaying the result.

The invention discloses a broadband colorimetric filtering sapphire fiber blackbody temperature sensor demodulation device. According to the device, a broadband high-pass and low-pass wavelength filter combination is adopted to perform filtering on a sapphire fiber blackbody radiation optical signal to obtain a short-wave optical signal and a long-wave optical signal, intensity detection is performed on the short-wave optical signal and the long-wave optical signal through a photoelectric detector, temperature signal demodulation can be realized according to the corresponding relation betweenthe intensity ratio of the short-wave optical signal to the long-wave optical signal and sensor detection temperature, the slope of the intensity ratio, changing along with a temperature signal, of the short-wave optical signal to the long-wave optical signal can be improved by adjusting the filtering effect of the broadband high-pass and low-pass wavelength filter combination on the sapphire fiber blackbody radiation optical signal, and therefore temperature demodulation sensitivity is improved.

The invention discloses a detection system based on an ED-MFKL (Er<3+>-doped microfiber knot laser) and a method. The laser is the ED-MFKL with Er<3+>-doped microfibers as an active medium and a knot as a resonant cavity; the Er<3+>-doped microfibers are formed by drawing a piece of Er<3+>-doped block glass by the aid of sapphire fibers with a direct drawing method; the knot is prepared from the Er<3+>-doped microfibers; the strong evanescent wave field of the microfibers is placed in the resonant cavity of the fiber laser, the detection sensitivity can be improved by multiple orders of magnitudes, and integration of output and sensing of laser is realized.

The invention discloses a ceramic sheath of a fiber high temperature detector, and belongs to the technical field of temperature detection. A sapphire fiber in which a temperature sensitive blackbody cavity is sputtered at the end portion and a ceramic sheath are included, the sapphire fiber penetrates into a fiber hole of the ceramic sheath, the diameter of the fiber hole matches that of the sapphire fiber, one end of the ceramic sheath is provided with a protective chamber, and one end of the blackbody cavity of the sapphire fiber is placed in the protective chamber. According to the invention, the blackbody cavity of the sapphire fiber is arranged in the protective cavity of the ceramic sheath, protection requirements are met, the blackbody cavity of the sapphire fiber makes full contact with a measured medium, and the instantaneity and accuracy of measurement are ensured; a fiber butt-joint structure is arranged in the sheath to reduce the utilization amount of the sapphire fiber and the manufacture cost; and the ceramic sheath is simple in structure, easy to prepare and suitable for batch production.

A high temperature-resistant doped fiber temperature sensor provided by the invention includes a light source, a light path splitter, a reference light path, a sensitive light path, a light power meter, and a data processing and storage device. The reference light path and the sensitive light path are connected in parallel. One end of the reference light path is connected with the light path splitter and the light source in turn and the other end of the reference light path is connected with the light power meter and the data processing and storage device in turn. The reference light path andthe sensitive light path are sensitive optical fibers. The high temperature-resistant doped fiber temperature sensor applies a doped sapphire crystal material as a sensitive optical fiber which includes an optical fiber core and a cladding material which covers the optical fiber core. The optical fiber core is prepared by a simple process, and has an excellent absorption behavior and high up-conversion strength, thus the application range of a sapphire fiber is greatly improved; the cladding material applies multi-component phosphate glass in which polycrystal alumina and Er<3+> are doped, thus the cladding material is low in cost and is able to meet the requirement of total reflection. The sensor has high detection sensitivity and can achieve an accurate result.

The invention discloses a system and a method for detecting a laser based on a micro-nano Er-doped fiber. The laser is a distributed Bragg reflector-micro-nanofiber laser and comprises an Er-doped micro-nanofiber serving as an active medium and SMF (single mode fiber)-engraved Bragg gratings serving as resonant cavities; the Er-doped micro-nanofiber is formed by drawing a piece of Er-doped block glass with a direct drawing method by the aid of sapphire fibers; two sections of selected SMFs are written with a method for irradiating a phase mask plate through ultraviolet light, Bragg gratings are formed respectively, and the lengths of tail fibers of two ends of each Bragg grating are not equal. The strong evanescent field of the micro-nanofiber is placed in a resonant cavity of the fiber laser, the detection sensitivity can be improved by several orders of magnitudes, and integration of laser output and sensing is realized.

The invention discloses a strain sensor able to withstand large deformation in a high temperature environment. The sensor relates to the technical field of mechanical sensors and is able to sense and measure largely deformed structures in a high temperature environment at low cost. The strain sensor comprises a protection box, springs and two sapphire fibers. The springs are cylindrical helical springs; the two sapphire fibers are integrated into different springs respectively. The protection box is formed by two oppositely arranged moveable boxes. The two sapphire fibers are sealed in the protection box, connected to the two boxes forming the protection box through one end of their own and closely attached to the surfaces of the structures at two sides of the protection box through high temperature withstanding adhesive agent. The springs integrated by one sapphire fiber and the protection box are in fixed arrangement to measure strains. The springs integrated by the other sapphire fiber and the protection box are not in fixed arrangement so as to measure the deformation caused by an environment to the sapphire fiber. The invention finds applications for large deformation measurement in a high temperature environment.

The invention relates to a preparation method of a single-mode sapphire fiber grating. The preparation method comprises the following steps: clamping and fixing a sapphire fiber on a displacement platform; adjusting the displacement platform so that laser transmitted by a femtosecond laser device is vertically shot into the sapphire fiber; adjusting the femtosecond laser device so that a first focusing light spot and a second focusing light spot are formed by laser on two sides of the center of the sapphire fiber in sequence, wherein the displacement platform drives the sapphire fiber to move along the axial direction at a constant speed so as to prepare a single-mode sapphire fiber; and writing a grating into the single-mode sapphire fiber so as to obtain the single-mode sapphire fiber grating. According to the preparation method of the single-mode sapphire fiber grating, the single-mode sapphire fiber grating with small insertion loss, narrow bandwidth and high precision can be obtained.

The invention discloses sapphire temperature sensor and a manufacturing method thereof and a temperature measuring system. The sapphire temperature sensor comprises a heat protection device, a sapphire fiber-optics probe and an optical fiber coupler. One end of the sapphire fiber-optics probe is a sensing head, and the other end of the sapphire fiber-optics probe is connected with the optical fiber coupler. The heat protection device surrounds the outside of a sapphire optical fiber. The sensing head is arranged at one end of the heat protection device, and the other end of the heat protectiondevice is connected with the optical fiber coupler. The sensing head is formed by wrapping the outer surface of one end of the sapphire optical fiber by a blackbody cavity, and the blackbody cavity is formed by heating multiple kinds of temperature sensing material particles to a molten state through plasma electric arcs and evenly spraying the temperature sensing material particles to the outersurface of one end of the sapphire optical fiber. The sapphire optical fiber temperature sensor manufactured through a plasma spraying method has the advantages of being wide in temperature measuringrange, high in heat response speed, high in precision, long in service life, low in cost and essentially insulated, the advantages are more prominent than those of a traditional thermometer, and the corrosion resistance and the electromagnetic interference resisting capacity are high.

The invention provides a high temperature resistant doped fiber temperature sensor, which comprises an optical source, an optical splitter, a reference optical path, a sensitive optical path, an optical power meter, and a data processing and storing device. The reference optical path and the sensitive optical path are connected in parallel, one end thereof is connected with the optical splitter and the optical source in sequence, and the other end thereof is connected with the optical power meter and the data processing and storing device in sequence. The reference optical path and the sensitive optical path are both sensitive fibers. The high temperature resistant doped fiber temperature sensor adopts a doped sapphire crystal material as a sensitive fiber. The material comprises a fiber core and a cladding material coated outside the fiber core. The preparation process of the fiber core is simple, and has excellent absorption characteristics and up-conversion intensity, thereby greatly improving the application range of the sapphire fiber. The cladding material uses multi-component phosphate glass doped with polycrystalline alumina and Er3+, is low in cost, and can meet requirements of total reflection. The sensor is high in detection sensitivity and accurate in result.

The invention discloses an extreme environment resistant sapphire fiber bragg grating sensor and a temperature detection method thereof. In view of the problem of application of a temperature sensor under extreme conditions, the extreme environment resistant sapphire fiber bragg grating sensor comprises: performing fusion splicing on a sapphire crystal fiber with a flat section and a flatly cut single mode fiber, as well as engraving a grating at a single mode near field position on the sapphire crystal fiber close to a fusion splicing point, and coating a protective material at the outside ofthe grated sapphire crystal fiber and the single mode fiber to obtain a sapphire crystal fiber bragg grating temperature sensor; performing mode selection on the light transmitted to a sapphire crystal fiber bragg grating area through the single mode fiber, so that the light of only a few modes or a single mode is transmitted into the sapphire crystal fiber bragg grating area; and when the external temperature changes, the effective refractive index and the grating period of the sapphire crystal fiber bragg grating change, so that the center wavelength changes, and the external temperature change is obtained by demodulation by recording the center wavelength of the sapphire crystal fiber bragg grating.

The invention discloses a mode controller improving the interference spectrum of a sapphire fiber FP sensor. A shaping filter is used to optically filter a light beam so as to remove most high light fields of a high order mode and obtain a light field matching the fundamental mode of the sapphire fiber FP sensor, and further the light filed input to the sapphire fiber FP sensor matches the fundamental mode of the sapphire fiber FP sensor, and the number of modes spread in sapphire fiber is controlled. The invention also provides a processing method of the shaping filter. Thus, the visibility of the interference spectrum of the sapphire fiber FP sensor can be effectively improved, the range of the sapphire fiber FP sensor is widened, and the measuring precision of the sapphire fiber FP sensor is improved.

A method for fabricating a sensor includes coating an end-polished sapphire fiber with aluminum to produce a sapphire fiber having an aluminum coating, anodizing the aluminum coating to produce an aluminum oxide coating, and removing the aluminum oxide coating from a distal end of the sapphire fiber.

The invention discloses a spiral sapphire fiber bragg grating and a preparation method and application thereof, and belongs to the technical field of optical fiber sensing. Preparation of a true three-dimensional spiral bragg grating is realized in a sapphire fiber by using a femtosecond laser processing system; and femtosecond laser has ultrahigh peak power and ultrashort pulse duration, laser additive and subtractive manufacturing is carried out on different materials, and preparation of three-dimensional structures and devices is achieved. When the peak power of the laser exceeds a nonlinear absorption threshold value of the material, a multi-photon absorption nonlinear effect can occur, and permanent refractive index change in the transparent material is induced in a laser focusing area. The femtosecond laser processing technology can realize permanent refractive index modulation inside the sapphire optical fiber, and the optical fiber high-temperature sensor is prepared. The prepared spiral grating has good structural symmetry and a large refractive index modulation area, a high-reflectivity and high-quality spectrum is obtained, the influence of external disturbance on the spectrum is reduced, and the spiral grating has good stability.

The invention provides a sapphire fiber Fabry-Perot (F-P) high temperature sensor provided with an inclination reflection surface as well as a preparation method and a temperature sensing system thereof, solving the problems that interference spectral quality of an existing sapphire fiber F-P high temperature sensor can be easily polluted by high temperature glue and dust and the interference spectral quality is influenced by other reflection surfaces except an F-P reflection surface, and having important research significance in high temperature detection fields such as aeroengine turbine blades, high temperature tail gas and metallurgical industry. The high temperature sensor provided by the invention comprises a sapphire fiber 1, a sapphire fiber 5 provided with the inclination reflection surface at the tail end and a ceramic ferrule 3; the sapphire fiber 1 and the sapphire fiber 5 provided with the inclination reflection surface are inserted into the ceramic ferrule 3, an air-filled cavity which can produce F-P interference is reserved between the end surfaces of the sapphire fibers 1 and 5 which are inserted into the ceramic ferrule 3, and high temperature cermica glue 2 is utilized for fixing respectively among the ceramic ferrule 3, the sapphire fiber 1 and the sapphire fiber 5 provided with the inclination reflection surface.

Provided is a cladded single crystal sapphire optical fiber. In one embodiment, the innovation provides a method for forming a cladding in a single crystal sapphire optical fiber by reactor irradiation. The reactor irradiation creates ions external to the fiber that enter the fiber, displace atoms in the fiber, and are implanted in the fiber, thus modifying the index of refraction of the fiber near the surface of the fiber and creating a cladding in the sapphire fiber.

The invention discloses a sapphire optical fiber F-P cavity cascade SFBG high-temperature strain sensor which comprises a gold-plated high-temperature-resistant single-mode optical fiber, one end of the gold-plated high-temperature-resistant single-mode optical fiber is provided with a single-mode optical fiber conical area, and the gold-plated high-temperature-resistant single-mode optical fiber is connected with a sapphire optical fiber through the single-mode optical fiber conical area. The end face, away from the gold-plated high-temperature-resistant single-mode fiber, of the sapphire fiber is a dip angle reflecting face. A trapezoidal air F-P cavity is formed in the sapphire optical fiber, a sapphire optical fiber Bragg grating is arranged in the sapphire optical fiber, and the trapezoidal air F-P cavity is located between the single-mode optical fiber conical area and the sapphire optical fiber Bragg grating; a stainless steel tube fixedly sleeves the outer side of the single-mode optical fiber conical area, an alundum tube fixedly sleeves the outer side of the sapphire optical fiber, and the alundum tube and the sapphire optical fiber Bragg grating are correspondingly arranged. According to the invention, a large-range measurement effect of a temperature range from room temperature to 1800 DEG C and a strain range of 0-1500 [mu] epsilon can be achieved, and the sensor is high in measurement sensitivity and high in precision.

The invention provides a sapphire optical fiber temperature sensor using a separate probe, which is manufactured according to the following steps: design and manufacture the sensor's probe temperature-sensing black body cavity, heat-insulating protective sleeve and related installation accessories according to the specific conditions of the temperature-measured medium; assemble Probes; design and manufacture converters, which include optical filters, photoelectric conversion circuits, preamplifier circuits, two-stage amplifier circuits, analog signal conditioning circuits, voltage output circuits, power supply voltage stabilization circuits, and voltage conversion circuits; finally, use quartz transmission A fiber optic bundle connects the probe to the transducer. In the present invention, the blackbody cavity is separated from the sapphire optical fiber, and the sapphire optical fiber is not in direct contact with the temperature-sensitive blackbody cavity. During temperature measurement, the sapphire optical fiber is relatively far away from the high-temperature environment. The temperature is lower than its degradation temperature and still can transmit the blackbody radiation signal normally, so that the upper limit of the temperature measurement of the sensor reaches 2600 ℃.

The invention discloses a sapphire reinforced aluminum alloy motor shell for an electric vehicle and a preparation method, aluminum alloy is doped with a multi-scale sapphire material, and the multi-scale sapphire material mainly comprises sapphire whiskers, sapphire fibers and sapphire nano powder. The sapphire reinforced aluminum alloy motor shell for the electric automobile is directly prepared by fully utilizing vacuum coating and additive manufacturing technologies; the surface of the sapphire is modified, so that good metallurgical bonding is formed between the sapphire and the aluminum alloy, obvious gaps and defects do not exist, the problems of poor interface bonding force and the like of the aluminum alloy enhanced by a single ceramic material at present can be well solved, and the service life and the adaptability of the aluminum alloy motor shell are greatly prolonged and improved.