A fiber Bragg grating demodulation system based on VCSEL laser and utilizing acetylene gas reference

This paper proposes a low-power, wide demodulation range solution for Fiber Bragg Gratings (FBG) based on voltage and current dual-wavelength tuning of VCSEL lasers. The paper first explains the principle of the demodulation system and then discusses the impact of driving voltage, current, and temperature on the emission wavelength of the laser. By investigating the wavelength scanning overlap range of the laser at different temperatures, the wavelength range of the FBG sensor is determined to be 4.5nm. The experimental results show that the demodulation system exhibits good wavelength repeatability, with the wavelength repeatability of all three channels within ±3pm. Furthermore, the overall power consumption of the system is only around 189mW, indicating that the demodulation system possesses the low power consumption characteristic and can be powered by portable power sources.