Principle of Fiber Bragg Gratings Measurement

This work discusses the measurement principle of fiber Bragg gratings (FBGs). Aim of the work is found a cheap method for measuring grating reflectivity and implement it into education. This principle takes advantage of laser diode wavelength dependence on temperature. Then FBG reflectivity can be measured by common laser diode and optical power meter without using expensive optical spectrum analyzer and broadband light source.