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

Distributed fiber optic sensing applies an entangled quantum network

FBG sensors for quantum networkQuantum-enhanced metrology is regarded as a popular area of research for years because of its promising applications, varying from atomic clocks to biological imaging. According to the researches, a non-standard distributed sensing system offers significant advantages compared to traditional fiber optic systems.

These researches help a team of scientists from Denmark to carry out an experiment on distributed fiber optic sensing and the benefits of employing an entangled quantum network to detect an averaged phase shift among numerous distributed sensing nodes. The fiber optic sensing technology uses several methods that enable collecting more accurate measurements in different areas.

The purpose of the new study is based on squeezed light and homodyne detection that is now established distributed fiber optic sensing techniques. The team aims at “measurement of a global property of numerous spatially separated objects and investigate whether probing these objects simultaneously with entangled light led to more accurate results than probing them individually”. 

Thus, the application of a quantum network to probe the objects simultaneously allows distributed sensing systems with far higher accuracy than that attainable when examining probes individually. To be more precise, the team measures the phase shifts (set with wave plates to a known value) by the fiber optic system that sends a weak laser beam through and detects the change in the light’s phase quadrature with homodyne detectors.

The benefit of applying distributed fiber optic sensing plays a really important role when it is necessary to measure the property of numerous objects connected in an optical network. Nevertheless, the losses in the network and detectors are required to be kept low in order to successfully raise the accuracy, alternatively, the quantum benefit of distributed sensing disappears.

The researchers succeeded in the experimental demonstration of the benefits connected with employing multi-mode entanglement for distributed fiber optic sensing. The thing is that the benefits have been previously predicted, however, only highly idealized scenarios and experimentally very difficult probe states or detection methods were taken into consideration. The developed fiber optic system demonstrates that these benefits are available even with current noisy sensing technology.

The fiber optic system finds potential applications in various areas of research and technology development. For instance, they provide a high sensitivity of molecular tracking devices, atomic clocks, and optical magnetometry methods. Moreover, the distributed fiber optic sensing gives valuable information about how quantum-enhanced metrology can be reached utilizing readily accessible technologies, for example, squeezed light generation and homodyne detection.

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

Fiber optic sensors make cities “smarter”

FBG sensors for smart citiesCompanies from the U.S. and Japan have developed for the first time a new fiber optic sensing technology that allows delivering traffic-related data to smart cities without tearing up streets. To be more precise, in smart cities connected intersections and traffic fiber optic sensors play a crucial role in the whole infrastructure. 

Thus, the combination of intersections with fiber sensors may greatly affect improving traffic flows resulting in congestion and pollution reduction, finally, improving life quality, resident safety, and raising economic activity and productivity. Additionally, these fiber optic sensors may promote pedestrian safety and save lives in different cities.

It should be noted that data information on traffic patterns and road congestions required to make the best application of such fiber sensing systems. Fiber optic technology makes it possible to get the data without physical inspections, putting in new infrastructure, or tearing up streets.

The concept has been already tested and demonstrated the opportunity to apply network infrastructure with existing fiber optic cables already installed in the ground as distributed optical sensors to compile data on city traffic patterns, road conditions, road capacity, and vehicle classification information.

Nowadays it is planned to enlarge tests of the fiber optic sensing technology and to decide how it can be employed in smart cities. The main purpose of technology is regarded as to enable “existing optical fiber providers to deliver smart city traffic-related data without tearing up roads or sidewalks”

The manufacturers apply new fiber optic technology and combine fiber sensors with artificial intelligence-based software to provide “intelligent traffic monitoring including the sensing of vehicle density, direction, speed, acceleration, deceleration and more”. The thing is that until recently it was required to install purpose-built optical fiber in very shallow spaces in the ground with fiber Bragg grating at predetermined intervals to collect and analyze this type of data information.

Today the proposed fiber optic solution suggests utilizing optical fibers already in the ground. The representatives of the companies confirm that these fiber optic sensors may lead or improve various public functions, for example, they allow first responders to identify and respond to gunshots as well as increasing municipalities’ capability to more quickly and efficiently detect earlier deterioration of bridges, tunnels, and other infrastructure.

Application of a single FBG interrogator in the distributed multi-parameter fiber optic sensor system estimated different characteristics of back-scattering light, which can be utilized to determine the static strain, dynamic strain, acoustics, vibrations, and temperatures for each optical fiber segment.

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

Chirped Fiber Bragg Gratings (CFBG) for high-speed fiber optic communications systems

A chirp is a linear variation in the grating period, that can be added to the refractive index profile of the grating. The reflected wavelength fluctuates with the grating period, broadening the reflected spectrum. A grating possessing a chirp has the ability to add dispersion—especially, different wavelengths reflected from the grating will be subject to different delays.

A non-uniform resonance wavelength along the length of the grating in a CFBG can be accomplished by varying the period or by varying the average effective refractive index. The average refractive index can be changed using different methods, for example, changing the amplitude of the reflective index modulation profile or variation the fiber in the region of the grating length. The chirped FBG was manufactured with the usage of a chirped phase mask to generate a variation in the period of the refractive index.

Chirped fiber Bragg gratings have been widely used for dispersion compensations in high-speed fiber optic communications systems because they are able to retard pulsed light depending on its wavelength. Experience has proven that ideas in one field find applications in another. Actually, this type of optical device has been attracting significant attention in the fiber optic sensing community, in high sensitivity sensors or wavelength discriminators in interrogation systems.

There are two prevailing fields of application of chirped FBG: measurement of curvature based on chirped fiber Bragg gratings and new interrogation system, written in an Erbium-doped fiber. The increasing demand for measurement of curvatures has stimulated the appearance of few sensing systems that depend on the intrinsic characteristics of fiber Bragg gratings. A curvature measurement technique using a smart composite consists of two chirped fiber Bragg gratings. The two gratings are embedded on the opposite sides of the composite laminate and serve as curvature sensors and as wavelength discriminators enabling a temperature-independent intensity-based scheme for the measurement of the radius of curvature.

FBG interrogation relies on the usage of the edge filtering concept applied to a chirped fiber Bragg grating written in an erbium-doped fiber as the processing element. Through the combination of the photon amplification of the erbium-doped fiber and of the distributed wavelength reflection characteristics of the chirped FBG, it becomes possible to reach different reading sensitivities and amplification of the remote sensing signal. The ability of chirped FBG has also been employed successfully in the development of interrogation techniques. One of these techniques uses the group-delay in a Sagnac loop interferometer and another the spectra response of broadband chirped gratings.