Apparatus for Measuring the Reflection Spectrum of a Fiber Bragg Grating with High Resolution

Sensors based on fiber-optic Bragg gratings are one of the most dynamically developing technologies in the field of fiber-optic sensor systems. The information parameter of such sensors is the shift of the maximum of the reflection wavelength under the action of the measured physical quantity. Wavelength shift measurement is done with special signal processing devices that are expensive. This article shows the possibility of using a general-purpose semiconductor laser to obtain the reflection spectra of fiber Bragg gratings is shown. The developed device allows us to obtain a reflection spectrum with a maximum resolution of at least 2 pm. In addition, the possibility of experimental registration of mode instability of a semiconductor laser is shown. The developed device can be used in a system for interrogating sensors based on fiber-optic Bragg gratings.