Fiber optic nano temperature sensor

Nano fiber optic temperature sensors are part of a particular type of fiber-optic sensors. The difference lies in the method of production. Use Fiber Optic Temperature Sensors usually specially prepared fiber ends. On these fiber ends, for example, to English miniaturized Fabry Perrot cavities, semiconductor chip of gallium arsenide (GaAs ) with Bragg gratings. When the fiber-optic nano- temperature sensors, however, nano -scaled GaAs powder is bound in adhesive and replaces the previous GaAs chip. Light scattering by the particles, the optical response is similar to that of the crystal. The sensors are through this particular production method more robust.

Production

Gallium arsenide crystals are processed to form a powder. The glass fiber needed for fiber production is first processed. For this purpose, the fiber must be stripped, be shortened to desired length and sanded at the fiber end. The end face is then carefully inspected. The fiber end must be uniform and free from cracks, cracks or spalling. As an adhesive, for example, can be used epoxy. The Gallum arsenide powder is first dissolved in the adhesive. Subsequently, the fiber end face is pressed into the adhesive mixture.

Structure & Principle of measurement

Nano temperature sensors consist of a Teflon ® coated fiberglass, which are provided at the tip of the fiber with a drop of gallium arsenide. The sensors are completely non- metallic. GaAs is from a light wavelength of 850 nm optically transmissive. The position of the band gap is temperature dependent and shifts about 0.4 nm / Kelvin. The associated measurement device includes a light source and a means for spectrally detecting the position of the tape edge. This allows the temperature to be determined very accurately.

Areas of application

Medical Applications

Temperature measurements in magnetic resonance imaging is very difficult. There prevail magnetic flux densities of several Tesla, and metallic sensors lead to errors in the image acquisition. For specific cancer therapies Nano temperature probes with diameters of 0.5 mm are available. These may be used minimally invasively to monitor the tissue temperature. Healthy tissue will not be heated above 40 ° C by exposure to electromagnetic fields while karzogenes tissue denatured by high temperatures. Other applications for this technology are measured in laser therapy. Through an endoscope laser energy is coupled, and the temperature measured at the therapy site with a fiber-optic nanoprobe.

Microwaves and RF environments

Chemical digestion under pressure and temperature for determination of trace and ultra-trace analysis in downstream processes or synthesis under mild conditions are increasingly being carried out in heated with microwave equipment. It was found that at certain pressure and temperature conditions, the yield or efficiency could be greatly improved with extraction or digestion process. Fiber optic nano- temperature sensors are almost the only way to control temperature-wise processes in microwave chemistry.

Because they offer a complete immunity to RF and microwave radiation. The sensors are designed by their special manufacturing process to withstand harsh and corrosive environments.

Generator and transformer

To ensure the reliability in electrical networks, the operators are increasingly used to measure at critical points in turbo-generators and power transformers temperature. High power generators are often filled with hydrogen for the purpose of more effective cooling. Fiber optic nano- temperature sensors to ensure accurate temperature measurement in a position in oil-filled transformers.

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