The team of the Swiss institute Empa has developed a “liquid” optical fiber
Fiber optics are very efficient at high speed data transmission, but they are also relatively fragile. An experimental new type of optical fiber offers a solution to this limitation. It has a core of liquid glycerol, technews.bg reports.
Optical fibers are usually made of thick glass or hard transparent plastic. The first type is able to transmit light pulses over long distances, but can break quite easily if bent or stretched. The second type works better over shorter distances, for example in buildings, but withstands bending better, although stretching will still cause it to break.
In search of an alternative, researchers at the Swiss Empa Institute have developed an optical fiber consisting of a liquid glycerin core contained in a transparent fluoropolymer shell.
“The two components of the fiber must pass through our centrifuge together under high pressure and at 200 to 300 degrees Celsius.“says lead scientist Dr. Rudolf Huffenus, quoted by NewAtlas.”Therefore, we needed a liquid with a suitable refractive index to achieve good functionality and with the lowest possible vapor pressure to produce the fiber.“.
The ability of the resulting fiber to transmit data in the form of light pulses is approximately equal to that of hard plastic optical fibers, but has a much higher tensile strength.
As a bonus, if the fiber is stretched, its color changes. This is due to the fact that glycerol continues to be present in the fiber, but as the liquid expands, the red dye particles in it move away. As a result, the color of the light emitted through the shell changes slightly.
This color change can be measured using an optical sensor, which allows users to know that the fiber – and the corresponding device that turns it on – is elongated or subjected to stress.
Naturally, the question arises here: won’t the glycerol just run out when the fiber is cut to the desired length?
“Under normal conditions, the liquid core is retained in the fiber due to capillary forces. However, if pressure is applied to the fiber, the liquid may be expelled“says Huffenus.”This can be prevented by sealing the end of the fiber“.
Scientists hope that the fiber will find application not only in data transmission, but also for power transmission in micromotors or microhydraulic systems.
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