Distributed fiber optic sensors: common applications

FBG sensors and common applicationsCommon communication channels apply fibers in fiber optic sensors where laser beam light passes along haul distances. These fiber sensors allow for determining, controlling, and measuring external parameters in a distributed format. Herewith, the optical fiber in a fiber optic system operates both as a distributed transducer and optical channel.

To be more precise, the fiber optic sensors measure various changes on specific parameters along with the transducer. Such factors as the dynamic range and the spatial resolution play a crucial role in distributed sensing but still have to be improved. The operating principle of fiber optic systems is based on “the incident light wave that produces acoustic waves through the electrostriction effect. It induces a periodic modulation of the refractive index of material that evokes a light-backscattering like a fiber Bragg grating of FBGs.”

It should be noted that a fiber sensor or sensing system is a tool that determines, measures physical or chemical parameters. Herewith, in the case of light use in such systems, this is a photonic or optical sensor. The fiber optic sensors, in turn, consist of optical fibers and the fiber optic technology around them.

Distributed fiber optic sensors detect and measure physical factors by Brillouin scattering of light in optical fibers. Brillouin scattering advances the development of precise distributed fiber optic systems. Additionally, these fiber sensors enable to measure specific variables.

Distributed sensing systems are very promising for structural health monitoring. The following parameters can be detected: strain and temperature, acoustic waves, and others. Moreover, these fiber optic sensors maintain severe environments and offer noise electromagnetic immunity, durability, and reliability.

The most common application of fiber sensors based on the Brillouin sensing technique includes laboratory implementation. Nevertheless, their applications are not limited to labs only. Distributed fiber optic sensors are widely used in such fields as:

  • The civil infrastructure where distributed sensing systems detects variables in bridges, railways, and land monitoring;
  •  Bridges and monitoring where compact fiber sensors promote accurate diagnostic load test;
  • Geotechnical structures monitoring for measuring and controlling of the stress distribution;
  • Pipelines monitoring by distributed fiber optic sensors in real-time for early warning of liquid and gas pipes;
  • Monitoring of some materials and structures, for instance, competition yachts or experimental vehicles.

Optromix is a fast-growing vendor of fiber Bragg grating (FBG) product line such as fiber Bragg grating sensors, for example, fbg strain sensors, FBG interrogators and multiplexers, Distributed Acoustic Sensing (DAS) systems, Distributed Temperature Sensing (DTS) systems. The company creates and supplies a broad variety of fiber optic solutions for monitoring worldwide. If you are interested in structural health monitoring systems and want to learn more, please contact us at info@optromix.com

FBG sensors for temperature and pressure measurement

FBG sensors for temperature and pressureNowadays fiber optic solutions play a crucial role in information technology. Fiber optic technology promotes the development of advanced fiber optic sensors. These fiber sensors offer numerous benefits that make them very attractive. The benefits include “durability, flexibility, biocompatibility, high sensitivity, and electromagnetic interference immunity.”

The applications of fiber optic sensors consist of numerous fields. They are widely used in medicine, environmental protection, industrial production, and structural health monitoring. Herewith, different types of fiber sensors allow for measuring various physical and chemical parameters. For instance, they sense temperature, acoustic, pressure, humidity, and others.

The production of distributed sensing systems requires different types of fibers. The following types are the most popular: photonic crystal, polarization-maintaining, double-core, sapphire optical fibers, etc. It should be noted that various fiber optic sensors use various measurement principles. Additionally, fiber Bragg gratings (FBGs) – the most popular measurement principle.

FBG sensors can also perform multi-parameter measurements to meet the practical demands of scientists. Thus, a team of researchers has demonstrated a cascaded multi-mode FBG sensor that performs the dual-parameter measurement. They apply optical fiber with several modes to create a distributed sensing system. Moreover, the FBG sensors measure the Brillouin frequency shift for temperature and strain sensing.

To be more precise, these FBG sensors have a hybrid structure (FBGs and FPI) with a nano-silica diaphragm on the tip. Besides, the total length of the fiber sensor is less than a human hair. These FBG sensors determine both environmental temperature and pressure. Therefore, such a fiber optic solution is highly promising in specific applications in severe environments.

Finally, the hybrid fiber optic sensor has been already produced and even tested. The distributed sensing system includes an FPI with a silica diaphragm. Also, fiber optic technology applies the femtosecond laser inscription technique and arc discharge methods. These FBG sensors demonstrate a high level of pressure and temperature sensitivity.

Additionally, the fiber optic sensor has an ultra-low level of cross sensitivities. “The temperature-induced error of the pressure measurement was –1.4286 kPa/ and ℃ pressure-induced error of the temperature measurement was ~0℃/MPa.” The mentioned-above benefits of FBG sensors make them perfect for numerous fields of applications.

Optromix is a fast-growing vendor of fiber Bragg grating (FBG) product line such as fiber Bragg grating sensors, for example, fbg strain sensors, FBG interrogators and multiplexers, Distributed Acoustic Sensing (DAS) systems, Distributed Temperature Sensing (DTS) systems. The company creates and supplies a broad variety of fiber optic solutions for monitoring worldwide. If you are interested in structural health monitoring systems and want to learn more, please contact us at info@optromix.com

Fiber optic sensors for plant detection

FBG sensors for plant detectionA novel fiber optic technology developed by researchers from Singapore becomes the basis for a novel fiber sensor for plant detection. The fiber optic sensors perform both detection and real-time monitoring of arsenic levels in underground environments. Such monitoring by distributed sensing systems is very important because it shows the presence and quantity of the metal.

The operating principle of this fiber optic system is based on the plantation of fiber sensors into plant tissue. Thus, fiber optic technology allows for detecting arsenic as low as 0.2 parts per billion. Compact and low-cost electronics records data. To be more precise, the combination of fiber optic sensors and plants operate as a fully functional environmental detection system.

It should be noted that such fiber optic systems can be useful in environmental monitoring and agriculture. The thing is that arsenic is a widespread contaminant in most crops, so its detection is crucial for structural health monitoring. Additionally, it is dangerous for human health because it causes cardiovascular disease and even cancers.

It is possible to tune selectively these fiber optic sensors to detect particular arsenic quantities. Herewith, the nanotubes used in fiber sensors do not photobleach, therefore, they have stable emission over time. These fiber optic systems are safe for plants in which they are installed. The technology has been already tested and demonstrated great improvement in time- and equipment-intensive sampling techniques.

“The newly demonstrated technique benefits from the natural ability of plants to extract analytes from their roots and move them throughout their body.” The fiber optic sensor embedded in the living plant presents perfect operation. The researchers use a camera in the fiber optic system to obtain real-time imaging and analysis. Herewith, this fiber sensor can be controlled with compact low-cost electronics.

The tests have been already carried out on spinach and rice, as well as a species of fern. Some properties of fern species promote optimizing the fiber optic sensors to locate extremely low concentrations of arsenic. Compared to the novel fiber system, conventional sensors have a 10 ppb limit.

Thus, fiber optic technology enables the development of more resistant crops to toxic contaminants. The researchers claim that it is possible to transform any living plants into fiber sensors for arsenic detection. Now it is planned to create a compact, portable fiber optic system to control the fluorescence of the sensors within the plants. Finally, novel fiber optic sensors are highly reliable no only in labs but also under field conditions.

Optromix is a fast-growing vendor of fiber Bragg grating (FBG) product line such as fiber Bragg grating sensors, for example, fbg strain sensors, FBG interrogators and multiplexers, Distributed Acoustic Sensing (DAS) systems, Distributed Temperature Sensing (DTS) systems. The company creates and supplies a broad variety of fiber optic solutions for monitoring worldwide. If you are interested in structural health monitoring systems and want to learn more, please contact us at info@optromix.com

Fiber optic sensors for biological liquids

FBG sensors for biological liquidsA team of scientists from Israel and Russia has developed a novel, straightforward, and low-cost fiber optic technology. It allows for the testing of liquid biological samples. Herewith, the developed fiber optic system is very promising in clinical settings, containing real-time testing during surgery.

To be more precise, fiber optic sensors are widely applied in the healthcare system for real-time diagnostic testing for biological samples. The fiber sensors offer a high level of sensitivity, however, usually “that sensitivity comes at a cost in terms of time and resources.”

Therefore, scientists tend to create simple, inexpensive fiber optic sensors as a more efficient alternative. It should be noted that they pay careful attention to the optical dispersion of the refractive index of a sample. The thing is that this process of the fiber optic system operates as a fingerprint of sorts that controls the changes in its composition.

Thus, the team has presented the concept of multispectral fiber optic sensing for liquid biological samples in both static and real-time modes. Herewith, fiber optic technology is accurate, robust, and highly sensitive to impurities in the sample. These fiber optic sensors will be helpful for diagnostic applications and real-time simulations of different biological processes.

The fiber sensors include hollow-core microstructured optical fibers. It is a specific type of optical fiber that keeps light inside a hollow core of the fiber optic system surrounded by microstructured cladding. Liquid passes through champers of fiber sensors, and the team registers spectral shifts of maxima and minima in the transmission spectrum.

These signals show the chemical composition of the sample. Additionally, the fiber optic sensors do not require an external cavity or interferometer. This is the main reason why fiber optic sensing is straightforward and virtually cheap to create. Such fiber optic technology has been already tested by scientists.

The fiber sensors test the concentration of bovine serum albumin, generally applied in such experiments, dissolved in water and phosphate-buffered saline solution. The fiber optic system demonstrated a resolution similar to the accuracy of standard albumin tests and complied with clinical requirements.

The potential application of these fiber optic sensors includes the analysis of biomarkers of various types. It is necessary to test the fiber sensors on other bioanalytics and then modify them to enhance specificity. The fiber optic technology opens new opportunities ina fast, inexpensive and robust analysis of blood and other bodily liquids in real-time.

Optromix is a fast-growing vendor of fiber Bragg grating (FBG) product line such as fiber Bragg grating sensors, for example, fbg strain sensors, FBG interrogators and multiplexers, Distributed Acoustic Sensing (DAS) systems, Distributed Temperature Sensing (DTS) systems. The company creates and supplies a broad variety of fiber optic solutions for monitoring worldwide. If you are interested in structural health monitoring systems and want to learn more, please contact us at info@optromix.com

Fiber optic sensors for ammonia detection

FBG sensors for ammonia detectionA team of scientists from Denmark in a collaboration with chemical engineers has presented novel accurate fiber optic sensors. They allow for significantly decreasing the level of air pollution. The operating principle of this fiber sensor is based on modern telecom technology. It helps to detect and measure ammonia in the atmosphere by the sensing system, a laser, and hollow-core optical fibers.

To be more precise, the fiber optic system provides continuous ammonia monitoring for agricultural application. Additionally, the fiber optic sensor can be created at a pretty low cost. The benefits of fiber sensors such as compact size, high reliability, and low cost meet the requirements of a portable system for detecting ammonia.

It should be noted that such a fiber optic technology is still under development. The thing is that the sensitivity of the fiber sensor requires improvements, which scientists try to perform. Even though the main purpose of the new sensing system is ammonia detection, it is possible to use fiber optic sensors for the detection of other gases, for instance, greenhouse gases. 

Moreover, fiber optic technology operates as a part of one agricultural project. In this project, scientists develop new techniques and technology to measure and reduce air pollution from the agricultural sector. Nowadays the agricultural sector is considered to be the main contributor to air pollution (mainly caused by ammonia). Therefore, agricultural pollution is the biggest environmental issue that requires efficient fiber sensors.

The thing is that now ammonia emissions are challenging to measure at the farm level. Compared to novel fiber optic sensors, traditional systems for ammonia detection have a high cost. Fiber optic technology is very promising with great prospects for agriculture. “The ability to continuously and cost-effectively track the development in ammonia emissions from agriculture offers completely new opportunities for the industry to experiment on decreasing the emissions.”

Scientists claim that there are already established figures considering air pollution from agriculture. Nevertheless, the future potential of fiber optic sensors may greatly transform the detection way of ammonia caused by agricultural farms. The new fiber optic technology promotes farmers to control their emissions continuously.

Finally, precise monitoring of ammonia emissions provided by sensing systems makes streamline operations far better. Thus, fiber sensors lead to emissions-based regulations that help reduce the environmental impact of agriculture. The development of these fiber optic sensors will continue until the next year.

Optromix is a fast-growing vendor of fiber Bragg grating (FBG) product line such as fiber Bragg grating sensors, for example, fbg strain sensors, FBG interrogators and multiplexers, Distributed Acoustic Sensing (DAS) systems, Distributed Temperature Sensing (DTS) systems. The company creates and supplies a broad variety of fiber optic solutions for monitoring worldwide. If you are interested in structural health monitoring systems and want to learn more, please contact us at info@optromix.com

Fiber optic sensors for metal ions detection

FBG sensor for metal detectionFluorescent fiber optic sensors find their popularity in online and in-situ detection of metal ions. These fiber sensors allow for predicting and preventing the environmental problems caused by the ions. To be more precise, this type of sensor is different from refractometer-based ones. The fluorescent fiber optic sensors have a simple structure and their properties play a crucial role in sensing performance.

It should be noted that metal ions cause heavy metal pollution resulting in significant harm to the environment and people. Nowadays metal pollution is regarded as a serious worldwide problem. Therefore, the problem requires quick and effective sensing systems to determine the level of metal ions pollution. The use of fiber optic sensors is a perfect solution.

Some researchers propose the use of fluorescent materials in the new fiber sensors. They claim that fluorescent optical fibers enable them to transmit valuable data for real-time sensing process. Additionally, these fiber optic sensors offer such advantages as long-life span and immunity to electromagnetic interference. The is the main reason why fluorescence sensing systems are ideal in field and emergency analysis.

The design of the fluorescent fiber sensors includes “an excitation light source, an optical fiber with the sensor probe, a spectrometer, and a computer.” The operating principle is based on the excitation light that expands along the fiber and the fiber optic sensor to obtain a fluorescent response back. Moreover, the researchers confirm that some biomaterials can collect heavy metal ions.

Thus, it is possible to apply their derivatives as fluorescent sensing systems. Recently researchers have created several fiber sensors based on fluorescent materials to detect metal ions that include the following:

  • Protein labeled sensing systems

It is not a novel type of fiber optic sensor, it has appeared almost 20 years ago. Protein labeled sensors do not depend on the fluorescent membrane and only transmit the light.

  • Nucleic acid-based fiber sensors

These sensors provide a high level of sensitivity and specificity. Also, nucleic acid-based sensing systems are very promising for on-site environmental monitoring. 

  • Luminescent nanomaterials-based fiber optic sensors

Even though they have more benefits than other types, these sensors demonstrate high selectivity at a minority of metal ions.

Finally, the mentioned above fiber optic solutions are very potential for the detection of metal ions, for example, in environmental water samples. Nevertheless, the sensing system is not ideal and has some problems to be overcome. 

Optromix is a fast-growing vendor of fiber Bragg grating (FBG) product line such as fiber Bragg grating sensors, for example, fbg strain sensors, FBG interrogators and multiplexers, Distributed Acoustic Sensing (DAS) systems, Distributed Temperature Sensing (DTS) systems. The company creates and supplies a broad variety of fiber optic solutions for monitoring worldwide. If you are interested in structural health monitoring systems and want to learn more, please contact us at info@optromix.com

Fiber optic sensors for deformation detection

Fiber optic sensors for deformation detectionThe development of stretchable fiber optic sensors promotes changing the operation of soft robots and smart systems. Recently, a team of scientists from the U.S. has developed a distributed fiber sensor that uses low-cost LEDs and dyes. The developed fiber optic sensors are stretchable and allow for finding different deformations (strain, pressure, bending).

To be more precise, these distributed sensors can be applied in soft robotic systems and augmented reality technology. The fiber optic sensors offer the opportunity to feel the same tactile sensations as animals use to navigate the natural world. The ability to determine deformations(for instance, strain, pressure, and bending) makes it possible to find exact locations.

The scientists claim that such a fiber optic technology will be useful for applications in sports medicine and physical therapy. The development of fiber sensors is based on previous technology, “in which light was sent through an optical waveguide, and a photodiode detected changes in the beam’s intensity to determine when the material was deformed.” Then numerous similar sensing systems have been created.

It should be noted that the operating principle is based on silica-based distributed fiber sensors. The distributed fiber optic sensors allow for recording the slightest wavelength shifts to determine, for example,  changes in humidity, temperature, and strain. Nevertheless, silica optical fibers are not efficient with soft and stretchable devices.

Herewith, it is easy to deform soft materials in difficult-to-reach areas. Therefore, scientists develop a fiber sensor that can overcome these challenges. The new fiber optic system consists of a stretchable light guide for multimodal sensing. The two cores of optical fiber are made of polyurethane elastomeric. The first core is transparent, the second has dyed.

A pair of cores in distributed fiber optic sensors increase the number of outputs. They, in turn, help to find various deformations, their exact location, and magnitudes. Compared to standard distributed sensors, new sensing systems do not need high-resolution detection equipment.

Stretchable fiber optic sensors apply small optoelectronics with a lower resolution. Thus, they have a lower cost, simple manufacturing, and can be easily installed into small systems. Moreover, it is possible to wear this fiber optic technology. For example, scientists have installed these fiber sensors in a 3D-printed glove.

Finally, this fiber optic technology allows scientists to measure tactile interactions in real life. Additionally, the team finds the way how distributed fiber optic sensors can advances virtual and augmented reality experiences. The thing is that these systems’ operation is based on motion capture, and fiber sensors can add new experiences.

Optromix is a fast-growing vendor of fiber Bragg grating (FBG) product line such as fiber Bragg grating sensors, for example, fbg strain sensors, FBG interrogators and multiplexers, Distributed Acoustic Sensing (DAS) systems, Distributed Temperature Sensing (DTS) systems. The company creates and supplies a broad variety of fiber optic solutions for monitoring worldwide. If you are interested in structural health monitoring systems and want to learn more, please contact us at info@optromix.com

Fiber optic sensors for smart battery charge

FBG sensors for battery chargeRecently a team of scientists from an American research center has presented a fiber optic technology used to create a battery management system applying embedded fiber optic sensors and machine learning. The thing is that the combination of fiber sensors and machine learning allows for developing more efficient and low-cost designs of smart battery charge management systems.

The important fact is that scientists pay careful attention to lithium-ion battery packs applied in hybrid and electric devices. Therefore, these fiber optic sensors allow for monitoring cell degradation and health data and predicting remaining battery life. Moreover, the fiber sensors have been already tested and demonstrated high precision across different use-cases at both the cell and module levels.

The operating principle of such a fiber optic system is based on the wavelength-shift detection technology that “measures the signals from fiber sensors installed within the active chemistry of the battery.” The fiber optic system has a resolution of 30fm and the KHz speed leading to obtaining the data about the charge’s state and failure warning.

Additionally, a read-out device records these data. Then machine learning algorithms evaluate it to offer real-time performance management of battery charge. Recently, the tests of fiber optic sensors have been finished at the module level of electric car batteries after tests on individual lithium-ion cells. According to the test results, these fiber sensors enable to decrease in the form factor of hybrid and electric car batteries by more than 25% leading to low-cost manufacturing at the same energy density.

Nevertheless, the team plans to perform additional testing and research to learn how to scale the fiber optic technology for larger batteries. Thus, scientists want to use original equipment manufacturers to examine the fiber optic system installed in hybrid and electric vehicles and to open new applications of fiber optic sensors for various energy and structural systems.

The thing is that the developed fiber sensors are regarded as a part of the energy technology program that aims at developing clean and abundant energy for a wide range of applications. Finally, the team paid attention to chemical energy storage for hybrid and electric systems, consumer electronics, and the electrical grid; advanced energy conversion devices; wireless fiber sensors; and advanced analytics before the novel fiber optic technology to increase energy utilization.

Optromix is a fast-growing vendor of fiber Bragg grating (FBG) product line such as fiber Bragg grating sensors, for example, fbg strain sensors, FBG interrogators and multiplexers, Distributed Acoustic Sensing (DAS) systems, Distributed Temperature Sensing (DTS) systems. The company creates and supplies a broad variety of fiber optic solutions for monitoring worldwide. If you are interested in structural health monitoring systems and want to learn more, please contact us at info@optromix.com

Compact fiber optic sensors

Compact FBG sensorsA team of scientists has produced novel compact fiber optic sensors that allow for detecting even slight force parameters affected by tiny objects. To be more precise, such a fiber sensor is ahead of standard force sensors based on micro-electro-mechanical technology.

The applications of new fiber optic sensors involve various fields beginning from medical devices to manufacturing. Even though such applications are numerous, however, the problem of compact and versatile sensing systems that enable to detect force om small objects yet remains.

This fiber sensor is considered to be the smallest one and most versatile force sensing system that meets all the requirements. The design of the fiber optic sensor includes silica-glass material of cylinder form with 800 microns long and 100 microns in diameter (similar to the diameter of a human hair).

Herewith, fiber optic technology has been already tested and allowed to detect “the force with a resolution better than a micronewton by applying it to measure the stiffness of a dandelion seed or the surface tension of a liquid.” Such benefits of fiber sensors as sensing of high-resolution and wide range are regarded as very useful for sensitive manipulation and machining of tiny objects, surface tension measurements, etc.

When it comes to micro-electro-mechanical technology, these sensing systems offer miniature force sensing capabilities but their applications are very limited because there are requirements in specific protective coatings and numerous electrical connections. It should be noted that the absence of a suitable coating leads to the absence of biocompatibility and such sensors can not be employed in water.

The new fiber optic sensors are made of glass. The scientists use a special etching process developed by them to produce complex optical fiber microstructures. The micromachining technique results in the appearance of a fiber sensor based on a Fabry-Perot interferometer.

Additionally, the coating and an air-sealed cavity of novel fiber sensors make them suitable for application in biochemical environmental conditions. It is possible to put these fiber optic sensors into different liquids, herewith, they detect positive and negative forces and does not require any additional coatings for numerous applications.

Finally, the fiber sensor measures the stiffness of a human hair and common dandelion seed. Moreover, such sensing systems measure the retraction force with a resolution of about 0.6 micronewtons and a range of about 0.6 millinewtons. Herewith, this tiny sensors can be a part of a complex fiber optic sensors, for instance, sensors that detect magnetic and electric fields.

Optromix is a fast-growing vendor of fiber Bragg grating (FBG) product line such as fiber Bragg grating sensors, for example, fbg strain sensors, FBG interrogators and multiplexers, Distributed Acoustic Sensing (DAS) systems, Distributed Temperature Sensing (DTS) systems. The company creates and supplies a broad variety of fiber optic solutions for monitoring worldwide. If you are interested in fiber optic sensor systems and want to learn more, please contact us at info@optromix.com

Novel FBG sensors and their promising applications

new FBG sensors A dramatic increase in the application of composite materials, involving aerospace technology, as well as other fields that need high reliability of structures, for instance, oil production, building industry, etc., makes the task of structural health monitoring very important. 

One of the most promising techniques is considered to be fiber optic sensors as an integral part of the monitoring system. Fiber optic sensors have several essential benefits over conventional ones. Compared to standard sensing systems, fiber sensors offer:

– a small mass;

– a high level of sensitivity;

– an electromagnetic compatibility;

– the ability to be combined in a network, as well as multiplexing;

– the compatibility with other systems for structural health monitoring;

– the ability to measure a variety of quantities.

A great benefit provided by fiber sensors also includes the ability to measure a variety of parameters such as deformation, pressure and force, electric and magnetic fields, sound and vibration, pH and viscosity, the presence of molecules, bacteria, and so on.

The sensitive element of a point fiber sensor is a fiber Bragg grating (FBG). The fiber Bragg grating reflects emission with a certain wavelength and it is transparent to other wavelengths. This selective reflection is achieved by writing a periodic structure in the optical fiber core. The reflected signal is registered by the receiving device.

FBG sensors do not have electronic components, i.e. they are passive. Thus, this property of FBG sensors opens up a wide range of possibilities for the application of such sensors in hazardous areas and areas with strong electromagnetic interference.

Herewith, multiple fiber Bragg gratings can be created on a single optical fiber. Each of the FBGs will reflect laser beam emission at its wavelength. This allows for producing a distributed monitoring system with wavelength multiplexing. The use of fiber optic sensors for structural health monitoring is regarded as very promising. 

The widespread use of composite materials in the aviation industry, as well as the creation and application in the future of “smart” materials and structures even with adaptive properties, will require continuous improvement of the structural health monitoring systems. Promising integrated sensing systems installed in optical fibers will significantly transform the way FBG sensors are employed in aviation materials and structures.

Optromix is a fast-growing vendor of fiber Bragg grating (FBG) product line such as fiber Bragg grating sensors, for example, fbg strain sensors, FBG interrogators and multiplexers, Distributed Acoustic Sensing (DAS) systems, Distributed Temperature Sensing (DTS) systems. The company creates and supplies a broad variety of fiber optic solutions for monitoring worldwide. If you are interested in structural health monitoring systems and want to learn more, please contact us at info@optromix.com