Reasons for the decrease in fiber optic grating wavelength
A variation of the period of the grating inscripted in a fiber optic – induced by mechanical or thermal perturbation – causes a shift of the reflected peak wavelength, due to the related optical path length variation. This is achieved by creating a periodic variation in the refractive index of the fiber core, which generates a. High-temperature-resistant fiber Bragg gratings (FBGs) are the main competitors to thermocouples as sensors in applications for high temperature environments defined as being in the 600–1200 °C temperature range. Due to their small size, capacity to be multiplexed into high density distributed. The solution came when Charles Kao and George Hockham of the British company Standard Telephones and Cables promoted the idea that the attenuation in the existing optical fibers could be reduced below 20 decibels per kilometer (dB/km), making fibers a practical communication medium.
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