An electrical engineer from the Netherlands has developed a fiber optic sensor based on fiber Bragg grating technology (FBG)with a super-precision of less than the size of an atom. Such FBG sensors favor the production of smaller chips, which in turn are required to develop faster computers.
The developed fiber sensor allows measuring deformations less than the width of an atom is possible to be measured. Thus, these fiber optic sensors offer a highly promising application that enables to improve the accuracy of current machines. It should be noted that even the slightest deformation of the wafers in machines may result in serious problems.
“These wafers are actually quite stiff, but because they are moved about at such great speed, they are subject to g-forces that slightly deform them. Measuring this deformation by FBG sensors gives the opportunity to compensate for it in some or other way, and opens up the possibility of producing even smaller chips.”
This is the main reason why the engineer began developing a fiber sensor based on FBG technology, enabling sensing these deformations of roughly one nanometer per meter. The operating principle of this extremely precise FBG sensor is that it is possible to measure the deviations in the frequency of laser beam light with high precision, as well as the principle used by fiber Bragg grating – an optical fiber of sorts treated in such a way that it becomes opaque for a very specific color of light.
Herewith, such a resonance frequency is dependant on the extent to which the optical fiber is stretched. Therefore, fiber Bragg gratings can be employed here to the moving parts as a way to measure the wafer’s deformation. The fiber optic sensing system based on FBG technology has been already tested in the lab. Although modern machines require dozens of such fiber sensors, it is not a challenge because FBG sensors are not expensive and light-weight.
The engineer claims that it succeeded in achieving the accuracy of 5 nanometers per meter, thus, the fiber optic sensor of a few centimeters in length allows measuring the deformation of a couple of dozen picometers, herein, that is less than the diameter of an atom. Nevertheless, several challenges have to be overcome before this incredible level of precision could be reached due to fiber Bragg gratings.
The first challenge is a need for sophisticated stabilization techniques to provide that the laser beam light has the right frequency. However, the main problem is considered to be the resonance frequency of the FBG sensor that depends on not only the deformation but also the temperature.
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