Fiber-Bragg-Grating Coupled Magnetostrictive Sensors for Magnetic Tracking of Biomedical Implants

Magnetostrictive strain sensors with high spinorbit coupling have been integrated with Fiber-Bragg-Grating sensors wherein the gap within the gratings varies with strain within the encapsulating magnetostrictive material. Terfenol-D has been chosen as the mm sized magnetostrictive material which exhibits the largest known bulk magnetostriction....

Test results of lateral load insensitive FBGs embedded in composites to suppress spectral distortion

Composite constructions are indispensable in current and future society. Fiber Bragg Gratings (FBGs) embedded in composite need to be carefully aligned with the material fibers to reduce inhomogeneous lateral load exerted onto the FBG which occurs due to the inhomogeneous nature of composite materials. Inhomogeneous load causes distortion of the...

Quantifying the performance of state of the art sensors to measure guided elastic waves

Elastic guided waves are carriers of information of the (change in) condition of plate-like structures like windturbine blades, airplane wings and road surfaces on bridges. To measure these guided waves we do not have to use piezos. Other sensors offer interesting benefits like contactless sensing, embedding, or measuring without electricity....

Innovative Fiber Bragg Grating Sensors for Highly Demanding Applications: Considerations, Concepts, and Designs

Measurement of physical parameters using mechanical transducers is an important part of fiber optical sensing. Fiber Bragg grating (FBG)-based sensors with dedicated transducers can be designed to measure different physical parameters and can operate in extremely harsh environments. This makes the FBG sensor very suitable for special...

Highly sensitive miniature fluidic flowmeter based on an FBG heated by Co2+-doped fiber

In this paper, we present a miniature fluidic flow sensor based on a short fiber Bragg grating inscribed in a single mode fiber and heated by Co2+-doped multimode fibers. The proposed flow sensor was employed to measure the flow rates of oil and water, showing good sensitivity of 0.339 nm/(m/s) and 0.578 nm/(m/s) for water and oil, flowing at v ...

Miniature FBG-based fluidic flowmeter to measure hot oil and water

In this paper, we present a miniature fluidic flowmeter based on a packaged FBG and laser-heated fibers. The flow rates of water and hydraulic oil were measured by utilizing the proposed flowmeter. The measured results exhibited good sensitivity of 0.339 nm/(m/s) for water and 0.578 nm/(m/s) for oil flow. Experimental results showed that the...

Zeolites as coating materials for Fiber Bragg Grating chemical sensors for extreme conditions

Important progress has been made towards the expanding of the limits of applicability of Fiber Bragg Grating (FBG) optical sensors. The development of new inorganic coatings consisting of MFI zeolite crystals (silicalite and ZSM-5) has opened up the possibility towards the use of this technology at high temperatures and pressures. Using two...

Fiber Bragg Grating Distributed Chemical Sensors

The functionalization of optical fibers containing Fiber Bragg Gratings is a very interesting approach in the development of distributed chemical sensors. We have shown a large variety of coatings, ranging from polymers to ceramics as responsive layers for the detection of many chemical species. Some coated fibers can be applied in extreme...

Miniature and low cost fiber bragg grating interrogator for structural monitoring in nano-satellites

In this paper we present a newly developed Fiber Optic measurement system, consisting of Fiber Bragg Grating (FBG) sensors and an FBG interrogator. The development of the measuring system is part of the PiezoElectric Assisted Smart Satellite Structure (PEASSS) project, which was initiated at the beginning of 2013 and is financed by the Seventh...

Error analysis of FBG-based shape sensors for medical needle tracking

Special optical fiber design to reduce reflection peak distortion of a FBG embedded in inhomogeneous material

During the last decades, the use of optical fiber for sensing applications has gained increasing acceptance because of its unique properties of being intrinsically safe, unsusceptible to EMI, potentially lightweight and having a large operational temperature range. Among the different Fiber Optic sensor types, Fiber Bragg Grating (FBG) is most...

Three-port interferometer in silicon-on-insulator for wavelength monitoring and displacement measurement

The wavelength of a narrow-band optical signal can be accurately tracked by means of an interferometer having a fixed path length difference. For example, a low-cost Fiber Bragg Grating (FBG) interrogation system which tracks the FBG reflection wavelength over time can be based on such an interferometer. Alternatively, an interferometer is...

Optical fiber sensors for medical applications: Practical engineering considerations

The advantages of optical fibers as medical sensors are recognized world wide nowadays. Insensitivity to electromagnetic disturbances and relative small dimensions are the most well known properties. The advantages of fiber optic sensors are especially valuable within environments with high temperatures, aggressive or explosive chemicals, strong...

The impact of electrosurgical heat on optical force feedback sensors

Electrosurgery enables cutting and coagulation (desiccation) of tissue for Minimally Invasive Surgery. Measurements performed by TNO with an infrared camera showed that the forceps of an endoscopic instrument can be over 300°C in temperature. During electro-surgery the surgeon relies on the power control and endoscopic images to perform the...

Fiber Bragg Grating sensors for structural health monitoring of Tsing Ma bridge: Background and experimental observation

The rapid expansion of the optical fiber telecommunication industry due to the explosion of the Internet has substantially driven down the cost of optical components, making fiber optic sensors more economically viable. In addition, the rapid development of fiber-optic sensors, particularly the fiber Bragg grating (FBG) sensors offers many...

High-speed structural monitoring using a Fiber Bragg Grating sensor system

We have developed a new interrogation/demultiplexing system for Fiber Bragg Grating (FBG) sensor array. Our approach combines a high readout frequency for all the FBG sensor channels with absolute measurement. This combination is in particular of interest for the detection of dynamic loading, which is the main cause of hair cracks development in...

Development of fiber optic sensors at TNO for explosion and shock wave measurements

Fiber Optic sensors are found to be very suitable for explosion and shock wave measurements because they are immune to Electromagnetic Interference (EMI). In the past few years, TNO has developed a number of sensor systems for explosion and shock wave measurements in which the optical fiber is a vital component. This paper presents a survey of...