Fiber Bragg gratings in bogie frame

FBGs for bogie frameThe application of fiber optic technology as temperature and strain gauges is quite surprising in bogie frames. To be more precise, these fiber optic sensors are applied for examining the carbon fiber bogie, in addition to standard surface-mounted electrical-resistance fiber optic strain gauges.

Optical fibers of 125 micrometers in diameter or 250 micrometers with a coating layer are perfect for this aim. The thing is that the optical fiber is improved to produce fiber Bragg gratings (FBG) in the fiber, efficiently producing a number of semi-reflective mirrors over short but equal intervals.

The operating principle of the FBG system is based on the reflection of the signal (a small amount of the signal at each semi-reflective mirror) when the light is transmitted through a fiber Bragg grating. Herewith, “the originally reflected wavelengths (without the influence of strain) from each Bragg grating are compared to the reflected wavelengths when the structure is loaded.”

It should be noted that in the case of FBG deformation by strain, the spacing between the semi-reflective mirrors is either enlarged (tension) or decreased (compression). Therefore, the change combined with the efficient refractive index and the period of the fiber Bragg gratings leads to a shift in the reflected central Bragg wavelength.

The thing is that the wavelength size demonstrates the strain magnitude. Nevertheless, there is the same effect that happened with temperature change, while the temperature effect is over 10 times the strain effect that is why the fiber optic technology needs to correct for temperature.

The researchers present the techniques applied to compensate for temperature where the fiber Bragg grating is placed close to the end-face of a cleaved optical fiber. The fact is the optical fiber with FBG is put in a capillary tube where one end is fused to the fiber, well away from the grating, and the opposite end is sealed. Finally, the FBG system responds only to temperature.

Nonetheless, it is not enough only to install several strain gauges into the bogie and link them to the instrumentation either. Ir is required to choose the proper fiber, for instance, bend-insensitive optical fibers are suitable. These are optical fibers where the diameter of the core includes 9.5-micrometer fibers with 4.5 mm long fiber Bragg gratings.

Additionally, it is necessary to properly install FBG systems to the bogie so as to act as a homogeneous part of the structure. Fiber Bragg gratings provide such benefits as efficient strain gauge transfer, capable to accommodate localized variations in the surface topology of the composite.

Optromix is a manufacturer of innovative fiber optic products for the global market. The company provides the most technologically advanced fiber optic solutions for the clients. Optromix produces a wide range of fiber optic devices, including cutting-edge customized fiber optic Bragg grating product line and fiber Bragg grating sensor systems. Moreover, Optromix is a top choice among the manufacturers of fiber Bragg grating monitoring systems. If you have any questions, please contact us at info@optromix.com

New concept of distributed fiber optic sensors

distributed FBG sensorsFiber optic technology promotes a new era of the Internet because optical fibers transmit huge amounts of data information all around the world. Herewith, fibers are regarded as an excellent platform for fiber optic sensors. It is possible to spread fiber sensors over hundreds of kilometers, simply install within structures, and even in a severe environment where the application of electricity is forbidden. Nevertheless,  optical fiber sensors have some inevitable problems as well.

The operating principle of an optical measurement is based on the light that touches the medium under test but conventional optical fibers are developed to perform the exact opposite. To be more precise, the design of optical fibers includes a glass cladding, with a much thinner, inner core. Herewith, the light is sent at the inner core, and every effort is made to keep light from leaking outside. “A substance under test, in most cases, lies outside the much larger cladding. Unfortunately, guided light does not touch upon much of the outside world.”

The only solution to the problem is coupling to the cladding modes that need for the inscription of permanent, periodic perturbations in the optical fiber medium (fiber Bragg gratings). FBGs are written at specific, discrete locations. Fiber optic sensor has limits to point-measurements only because their erasement or movement are prohibited. Optical fiber sensors are perfect in spatially-distributed analysis, in which every fiber optic segment operates as an independent measurement node. Additionally, it is possible to use two strong optical waves into the optical fiber instead as an alternative to the fiber Bragg gratings.

Also, there are Brillouin dynamic gratings, which can be switched on and off at will compared to standard FBGs. It is possible to short segments of arbitrary locations, and scan along with the optical fiber. The thing is that the developed distributed fiber optic sensor is considered to be a first of its kind. Researchers have overcome some challenges: they succeeded to demonstrate the accurate measurement of refractive index outside the cladding boundary of traditional, unmodified optical fiber resulting in an 8cm spatial resolution. Herewith, the analysis demonstrates proper identification of short fiber optic sections immersed in water and ethanol, and clearly distinguished between the two. 

The researchers claim that it is a new concept of distributed fiber optic sensors. Such fiber sensors allow overcoming a decades-long challenge: fiber optic sensors perform the distributed mapping of refractive index outside the cladding of conventional optical fiber, where light does not achieve. The applications of distributed fiber optic sensors include leak detection in critical infrastructure, and process monitoring in the petrochemical industry, desalination plants, food and beverage production, and more.

Optromix is a manufacturer of innovative fiber optic products for the global market. The company provides the most technologically advanced fiber optic solutions for the clients. Optromix produces a wide range of fiber optic devices, including cutting-edge customized fiber optic Bragg grating product line and fiber Bragg grating sensor systems. Moreover, Optromix is a top choice among the manufacturers of fiber Bragg grating monitoring systems. If you have any questions, please contact us at info@optromix.com

FBG sensors prevent tunnel fire

FBG sensors for fire detectionTunnel fires are not regarded as usual, however, they also can perform great damage to lives and properties if they take place. The process of fire detection inside the lengthy and curved tunnel is challenging. Nevertheless, fiber optic sensors based on fiber Bragg grating or FBG technology allows detecting tunnel fires and FBG sensors are considered to be a novel methodology that determines not only the presence but also locates the fire inside the tunnel.

To be more precise, FBG sensors are installed across the inner sides of the tunnel where they control it by the optical spectrum analyzer or wavelength division multiplexing sensor interrogator at the exit. “The change in the center wavelength from the original spectrum at the output denotes the temperature change (fire occurrence) inside the tunnel.” FBG fiber optic sensors offer output with more precision, herewith, fiber Bragg gratings can hold very high-temperature values.

It should be noted that it is possible to detect fires applying various ways, for instance, installing temperature sensors inside the tunnel or controlling the tunnel through the camera. Temperature sensors enable to sense of tunnel fires but their location presents difficulties. Moreover, such a temperature sensor as a thermistor can not stand very high temperatures (1000˚C) as well as there is a problem of self-healing.

FBG sensors, in their turn, provide a highly efficient process of sensing and locating. The thing is that fiber Bragg gratings in fiber optic sensors lead to a narrow range of wavelengths to shift and the rest of it to transmit through it. The center of the reflected wavelength is Bragg’s Wavelength. The features of FBG sensors allow measuring temperature or strain changes in the structures. Additionally, FBG fiber optic sensors have a greater temperature steadiness ability, more immune to electromagnetic interferences, longer lifetime, explosion safe and it is possible to be multiplexed.

Fiber Bragg grating is a short part of optical fibers that reflects a specific light wavelength and transmits all other wavelengths. FBGs operate as an optical notch filter. The operating principle is based on the Bragg grating patterns inside the fiber that perform the reflection. The design of fiber Bragg gratings includes holographic interference or a phase mask to undergo a short length of optical fiber to a periodic distribution of light intensity. 

The developed FBG sensors have been already tested and demonstrated the following results: the sensitivity value of the fiber optic sensor achieves 20 pm/˚C. Also, it is possible to increase the accuracy of fire location inside the tunnel by increasing the number of FBG fiber optic sensors for the considered tunnel length of 4 km. Thus, FBG technology can help to perform operations very fast and can save many lives and properties.

Optromix is a manufacturer of innovative fiber optic products for the global market. The company provides the most technologically advanced fiber optic solutions for the clients. Optromix produces a wide range of fiber optic devices, including cutting-edge customized fiber optic Bragg grating product line and fiber Bragg grating sensor systems. Moreover, Optromix is a top choice among the manufacturers of fiber Bragg grating monitoring systems. If you have any questions, please contact us at info@optromix.com

Extremely precise FBG sensors promote smaller chips

FBG sensors for chip developmentAn electrical engineer from the Netherlands has developed a fiber optic sensor based on fiber Bragg grating technology (FBG)with a super-precision of less than the size of an atom. Such FBG sensors favor the production of smaller chips, which in turn are required to develop faster computers.

The developed fiber sensor allows measuring deformations less than the width of an atom is possible to be measured. Thus, these fiber optic sensors offer a highly promising application that enables to improve the accuracy of current machines. It should be noted that even the slightest deformation of the wafers in machines may result in serious problems.

“These wafers are actually quite stiff, but because they are moved about at such great speed, they are subject to g-forces that slightly deform them. Measuring this deformation by FBG sensors gives the opportunity to compensate for it in some or other way, and opens up the possibility of producing even smaller chips.”

This is the main reason why the engineer began developing a fiber sensor based on FBG technology, enabling sensing these deformations of roughly one nanometer per meter. The operating principle of this extremely precise FBG sensor is that it is possible to measure the deviations in the frequency of laser beam light with high precision, as well as the principle used by fiber Bragg grating – an optical fiber of sorts treated in such a way that it becomes opaque for a very specific color of light.

Herewith, such a resonance frequency is dependant on the extent to which the optical fiber is stretched. Therefore, fiber Bragg gratings can be employed here to the moving parts as a way to measure the wafer’s deformation. The fiber optic sensing system based on FBG technology has been already tested in the lab. Although modern machines require dozens of such fiber sensors, it is not a challenge because FBG sensors are not expensive and light-weight.

The engineer claims that it succeeded in achieving the accuracy of 5 nanometers per meter, thus, the fiber optic sensor of a few centimeters in length allows measuring the deformation of a couple of dozen picometers, herein, that is less than the diameter of an atom. Nevertheless, several challenges have to be overcome before this incredible level of precision could be reached due to fiber Bragg gratings.

The first challenge is a need for sophisticated stabilization techniques to provide that the laser beam light has the right frequency. However, the main problem is considered to be the resonance frequency of the FBG sensor that depends on not only the deformation but also the temperature. 

Optromix is a manufacturer of innovative fiber optic products for the global market. The company provides the most technologically advanced fiber optic solutions for the clients. Optromix produces a wide range of fiber optic devices, including cutting-edge customized fiber optic Bragg grating product line and fiber Bragg grating sensor systems. Moreover, Optromix is a top choice among the manufacturers of fiber Bragg grating monitoring systems. If you have any questions, please contact us at info@optromix.com

FBG sensors measure pH to study tissue growth

FBG sensors for pH measurementA team of researchers from the U.S. continues developing a fiber optic sensor based on fiber Bragg grating or FBG technology that helps to study tissue growth in the lab. The operating principle of the FBG sensor is based on a light-based signal to measure pH that is considered to be a highly important quality in cell-growth studies.

It should be noted that compared to traditional sensing systems, it is possible to use the fiber sensor to control the environment in cell culture for weeks at a time without the necessity to bother the cell-growth environment. For several years, the researchers have designed photonic sensors that apply optical fibers etched with a fiber Bragg grating (FBG). Temperature or pressure changes lead to transform the wavelengths that are able to get through the fiber Bragg grating.

Such a sensing system has been already tested and shows that fiber sensors with Bragg gratings can be easily adapted to pH measurement. The application of a fiber optic-based platform featuring FBGs promotes the development of a fiber optic sensor that “measures the heat released by pH-sensitive chromophores upon absorption of light”.

Thus, due to this fiber sensing system, the researchers have succeeded to compare visible light absorption by the chromophores to the heat released and changes in the fiber Bragg grating signal over a pH range of 2.5 to 10. To be more precise, firstly, the team fills a petri dish with a solution made with red cabbage juice powder that transforms color in response to changes in pH.  Then the researchers put one optical fiber above the dish, connecting the optical fiber to a laser pointer, and shine the laser beam into the sample. 

Additionally, they install a second optical fiber with FBGs as the temperature sensor in the cabbage juice solution. Herewith, the team controls manually the pH levels in the solution. Shining the solution above, it absorbs the laser beam to different degrees depending on its pH level. The fiber optic sensor operates as a thermometer and detects these tiny changes in the juice’s heat.

A second color into the solution added by the researchers demonstrates that the fiber sensor offers its operation over a wide range. Moreover, further researchers show that the pH measurements by the FBG sensor are precise to plus or minus 0.13 pH units and are stable for at least three weeks.

Finally, it is planned to perform tests on “how cell cultures are affected by the slight, temporary temperature changes (about 1 to 2 kelvins) in localized areas of the sample that occur as a result of this measurement technique” by applying the developed fiber sensing system. Also, the temperature changes are required to reduce in the future as much as possible because over time the fiber sensors could be developed to control the growth of tissue in the human body

Optromix is a manufacturer of innovative fiber optic products for the global market. The company provides the most technologically advanced fiber optic solutions for the clients. Optromix produces a wide range of fiber optic devices, including cutting-edge customized fiber optic Bragg grating product line and fiber Bragg grating sensor systems. Moreover, Optromix is a top choice among the manufacturers of fiber Bragg grating monitoring systems. If you have any questions, please contact us at info@optromix.com

Compact FBG sensors control traffic density

FBG sensors for traffic controlA new compact sensing system based on fiber Bragg grating technology has been designed to control urban traffic density up to 80 kph. The sensing technology includes a 2.5-m-long and a 2-cm-high fiber optic sensor made from a combination of silicone addition rubber and fiber Bragg grating put inside a carbon tube.

The design of the compact FBG sensors allows monitoring and detecting the traffic density and car crossing in a single lane. It should be noted that such a sensing system has been already tested in real traffic and demonstrated quite a high detection rate of 98.946% based on the control of 1518 vehicles of various types and sizes.

To be more precise, traffic sensing systems are considered to be special devices that determine input data and information for other transport infrastructure systems. It is possible to install traffic sensors next to, above, into, or onto a road’s surface. The fiber optic sensors control “the presence of a vehicle, vehicle speed, vehicle classification, wheelbase and number of axles, total vehicle weight, road axle load, and occupancy, all of which indicate the traffic flow quality”.

The thing is that sensing systems based on optical fibers provide the following benefits: robustness, precision, high sensitivity, electromagnetic and chemical resistance, electrical passivity, and a broad temperature operating range. Additionally, it is possible to use fiber optic sensors in hybrid systems. The operating principle of fiber sensors is based on transmitting and receiving a laser or infrared beam from an emitter to a receiver.

Another type of fiber optic sensor is distinguished which is a micro-motion one. Such a fiber sensor operates using the increasing of optical fiber attenuation. Herewith, these optical fibers have special protective coatings and they are installed into a roadway. Nevertheless, their application is experimental, and these fiber sensors are not employed in general practice.

Also, the DAS technology (Distributed Acoustic Sensor) can be used for the same purposes. For instance, DAS systems apply a single optical fiber to control multiple traffic parameters, such as detecting a car, its direction, its speed, etc. However, FBG sensors require proper protection in order to avoid damage to the sensors. The use of composite fiber protection to the FBG sensors enables us to successfully solve the current problem.

The high sensitivity of portable FBG sensors and success rates in determination vehicles are regarded as a good supposition for expanding research and future developments for monitoring automotive traffic. Nowadays researchers plan to improve the design of fiber sensors to provide a more stable sensitivity, as well as to expand the determination capabilities of the sensing system, and to produce the sensor for year-round application.

Optromix is a manufacturer of innovative fiber optic products for the global market. The company provides the most technologically advanced fiber optic solutions for the clients. Optromix produces a wide range of fiber optic devices, including cutting-edge customized fiber optic Bragg grating product line and fiber Bragg grating sensor systems. Moreover, Optromix is a top choice among the manufacturers of fiber Bragg grating monitoring systems. If you have any questions, please contact us at info@optromix.com

A new application of FBG sensors

new FBG sensorsA team of researchers offers a new application of fiber Bragg grating sensors (FBG sensors) in the construction and characterization of Micro Pattern Gaseous Detector. Such a FBG sensing system includes 144 gas electron multiplier chambers of about 0.5 m2 active area each. It should be noted that FBG technology has been applied in high energy physics only for high precision positioning and re-positioning fiber sensors due to their benefits (low cost, easy installation, low space consumption). Nowadays the most common application of fiber Bragg gratings remains the use for very accurate strain measurements in material studies.

Now FBG technology is used as flatness and mechanical tensioning sensors employed to the wide GEM foils of the GE1/1 chambers. FBG sensor array allows detecting the optimal mechanical tension applied and characterizing the mechanical tension that should be applied to the foils. A new application of FBG sensors has been already tested and demonstrated great results that can determine a standard assembly procedure and possible future developments.

Fiber Bragg gratings are considered to be a type of distributed Bragg reflector, developed by a short segment of optical fiber that enables one to reflect certain wavelengths of light and transmit all others. The operating principle of FBG sensors is based on “the creation of a periodic variation in the refractive index of the fiber core, which generates a wavelength-specific dielectric mirror”. Thus, the FBG sensing system can be applied as a strain measurement device because changes in fiber Bragg gratings lead to various light frequency responses.

One more application of FBG sensors in GEM chamber construction includes the opportunity to be applied as a load gauge for accurate measurement of the tensile load employed to the foils, of the various layers, at the same moment. The thing is that this FBG application plays a crucial role in the case of the GE1/1 chambers because the foils are stretched through screwing nuts with a dynamometric screwdriver during their assembly procedure, therefore, it is necessary to know accurately how much to strain the foils to escape to stretch them too much.

The testing of fiber Bragg grating sensors consist of proper stretching of the GE1/1 GEM stack, then the researchers removed a single stretching screw from the chamber and replaced it with an eyelet screw with installed stainless steel wire applied to set various weights. Additionally, it was necessary to add weights in different steps until they applied load achieves in the fiber Bragg gratings facing the eyelet the same response as when stretching of the GEMs occurs by the traditional screw.

Finally, the technology of FBG sensors is regarded as a highly reliable glue-less technique that offers the correct tensioning of the three GEM foils. The correct tension across the GEM stack leads to uniform gaps resulting in the required performance of the detector. Moreover, FBG sensors operate successfully as load gauges for accurate detection of the used stretching force to GEM foils.

Optromix is a manufacturer of innovative fiber optic products for the global market. The company provides the most technologically advanced fiber optic solutions for the clients. Optromix produces a wide range of fiber optic devices, including cutting-edge customized fiber optic Bragg grating product line and fiber Bragg grating sensor systems. Moreover, Optromix is a top choice among the manufacturers of fiber Bragg grating monitoring systems. If you have any questions, please contact us at info@optromix.com

FBG sensors for measuring human body temperature

FBG sensors for temperature measurementThe opportunity to measure body temperature plays a crucial role in both physiological studies and clinical investigations. New wearable sensors based on fiber Bragg grating or FBG technology offer such an opportunity in intelligent clothing for human body temperature measurement.

The main purpose of the development is the integration of FBG sensors into functional textiles to enhance the abilities of wearable fiber optic solutions for body temperature monitoring. Thus, the FBG sensing system provides a temperature sensitivity of 150 pm/°C, which is almost 15 times higher than that of a bare fiber Bragg grating.

It should be noted that fiber Bragg grating is regarded as a type of distributed FBG reflector installed in a short segment of optical fiber that reflects particular wavelengths of light and transmits all the others. The FBG technology is used here as an inline optical filter to block specific wavelengths, or as a wavelength-specific reflector.

Additionally,  FBG sensors offer great benefit over electronic sensing systems for the use in intelligent structures, civil engineering, harsh environmental conditions, built structural health monitoring system and other. Distributed temperature sensors based on fiber Bragg gratings measure human body temperature at fiver places: left chest, right chest, left armpit, right armpit, and at the center of the upper back. Herewith, the data information provided by these FBG sensors at five places is not the same because different parts of the human body have different temperatures.

The application of distributed temperature sensors based on FBG technology allows developing a sample of intelligent clothing and testing the heat transmission mechanism from numerous aspects. A new mathematical model of heat transmission for the human skin, the air and clothing has been created. Therefore, FBG sensors provide the theoretical basis of human temperature measurement applying intelligent clothing with distributed temperature sensors and demonstrate the implementation of optical fiber grating into the clothing. 

Finally, the temperature measured by DTS systems can be useful to represent human body temperature in clinics. Nonetheless, it is planned to enlarge “research in intelligent clothing to cover the measuring and recording of real-time physiological information, such as human respiration, heartbeat, blood pressure, and other physiological signals.”

The biomedical application of wearable FBG sensors, which are non-intrusive, non-invasive, and continuously being monitored, is considered to become a highly potential monitoring and diagnostic devices. Thus, these distributed temperature sensors can determine and process physiological signals, extract signal characterization, transmit data, and have other basic options.

Optromix is a manufacturer of innovative fiber optic products for the global market. The company provides the most technologically advanced fiber optic solutions for the clients. Optromix produces a wide range of fiber optic devices, including cutting-edge customized fiber optic Bragg grating product line and fiber Bragg grating sensor systems. Moreover, Optromix is a top choice among the manufacturers of fiber Bragg grating monitoring systems. If you have any questions, please contact us at info@optromix.com

Spacecraft structural health monitoring by fiber Bragg grating sensors

FBG sensors for spacecraft monitoringFiber Bragg gratings or FBGs are considered to offer a markworthy application in the fastly growing aerospace industry. The FBG benefits such as phenomenal optical multiplexing make them possible to use as smart fiber optic sensors that allow them to perform structural health monitoring of airborne vehicles and maintain and lengthen their lifetime. Thus, FBG technology plays a crucial role in the spacecraft industry where tiny errors and damage can lead to death for the crew aboard.

To be more precise, fiber Bragg grating is regarded as a thin, tubular optical fiber device that includes a physical “grating” area at its core. Herewith, the core of fiber Bragg gratings is not homogeneous, it has a periodic variation in the refractive material index. The principle of FBG technology operation is based on the change in the core refractive index because of which “some light will be reflected and some will be transmitted through the tube.” Additionally, the periodic spacing of the grating influences the reflected vs transmitted wavelength of light.

FBGs demonstrate efficient operation as narrow bandwidth light filters. The FBG application includes a block of specific wavelengths and transmission of others that is similar to the mode selection that appears in laser cavities. Nevertheless, such features as pressure and strain as well as vibration and displacement also influence the wavelengths of fiber Bragg gratings, while the temperature may lead to thermo-optic effects in the silica material that conventional FBG sensors are made from. Therefore, the mentioned FBG properties allow using them as fiber optic sensors to measure various physical effects at the same time.

FBG technology opens an opportunity to use FBG sensors to determine ultrasonic and acoustic wave signals, with a unique application in structural health monitoring of aerospace vehicles. The thing is that acousto-ultrasonic detection by fiber Bragg grating sensors is highly effective in damage detection if the spacecraft is not mobile (on the ground). Herewith, an ultrasonic actuator is required to produce the ultrasonic signals. It should be noted that the damage detection by FBG sensors is very accurate and quantitative because it allows controlling both the waveform function and the repetition of measurements.

Nevertheless, the limitations in resolution and bandwidth of conventional tools applied with fiber Bragg grating sensors, for example, optical spectrum analyzers, do not provide accuracy in high-frequency detection. It is necessary to use a demodulation method to interpret the detected signals for accurate detection of ultrasonic waves. Herewith, the installation technique of the fiber Bragg gratings is also important in ultrasonic detection. The installation of the fiber Bragg grating sensors into an aerospace vehicle or craft requires the use of various techniques. For example, it is possible to place FBGs into composite materials, however, it may cause signal distortion. This is the reason why a better way is gluing FBG sensors on with some adhesive, such as epoxy. 

Optromix is a manufacturer of innovative fiber optic products for the global market. The company provides the most technologically advanced fiber optic solutions for the clients. Optromix produces a wide range of fiber optic devices, including cutting-edge customized fiber optic Bragg grating product line and fiber Bragg grating sensor systems. Moreover, Optromix is a top choice among the manufacturers of fiber Bragg grating monitoring systems. If you have any questions, please contact us at info@optromix.com

The development of fiber Bragg gratings using highly doped aluminosilicate glass optical fibers

FBGs made of doped fibersThe continuous development of high-temperature fiber Bragg grating technology (FBG technology) promotes a significant increase in novel applications. For instance, nowadays FBG applications include such fields as “the temperature profiling of high-temperature manufacturing equipment, monitoring of fuel combustion machinery, temperature regulation of large diesel engines in trains, as well as assessment the structural integrity of a building post-fire”.

Additionally, high-temperature FBG technology is used in oil and gas industries where the resistance to the temperatures higher than 500 °C is totally recommended. To be more precise, the sensors based on fiber Bragg gratings are able to stand temperature conditions below and above 800 °C. Herewith, the thermal stability of FBG sensors depends closely on the intrinsic thermal stability of the core-cladding materials.

This is the reason why the development of fiber optic technology with higher thermal resistance, for example, the molten core technique, is still required. Thus, it was decided to apply a circular core/cladding glass optical fiber containing a yttrium-doped aluminosilicate core and a silica cladding in FBG sensors that may withstand about 900 °C. 

The following types of FBG sensors are based on the nature of refractive index modifications induced by laser irradiation. The following types of FBGs  are distinguished:

  • The type I in fiber Bragg gratings produces a laser irradiation regime that emits an isotropic increase of the refractive index.
  • The type II in FBGs, in its turn, has a connection with the creation of an anisotropic index change upon irradiation, generally emitted by the presence of nanogratings, and leads to the observation of form birefringence.
  •  Ultra-high temperature regenerated fiber Bragg gratings are able to operate above 800 °C in silica optical fibers. Therefore, these FBGs find their application in such areas as the profiling of high-temperature manufacturing equipment, dual pressure/temperature sensing for gas turbines, sodium-cooled nuclear reactors, high-temperature air flow meters for internal combustion engines and train engine temperature regulation.
  • Femtosecond fiber Bragg gratings are made by ultrafast laser systems usually in the NIR spectral range, resulting in their use as temperature sensors for monitoring fluidized bed combustors, as well as for radiation-resistant temperature sensors.
  • Sapphire fiber Bragg gratings allow achieving even higher temperature operation by using materials with higher melting points.

Optromix is a manufacturer of innovative fiber optic products for the global market. The company provides the most technologically advanced fiber optic solutions for the clients. Optromix produces a wide range of fiber optic devices, including cutting-edge customized fiber optic Bragg grating product line and fiber Bragg grating sensor systems. Moreover, Optromix is a top choice among the manufacturers of fiber Bragg grating monitoring systems. If you have any questions, please contact us at info@optromix.com