In the current rapidly advancing aerospace field, more stringent requirements are placed on the performance of fiber optic sensing demodulation systems. This study aims to address the wavelength hopping issue in the Modulated Grating Y-branch (MG-Y) laser during channel switching, so as to improve the wavelength stability of the laser and improve the resolution accuracy of the vibration signal in the fiber sensing demodulation system under high-speed scanning.

Through an in-depth investigation of the tuning characteristics of the MG-Y laser, we revealed the significant impact of switching frequency on the output wavelength. Then, we developed a wavelength hopping model for the MG-Y laser at different switching frequencies. Based on this model, we designed and implemented a wavelength hopping compensation system for the MG-Y laser. Additionally, we proposed a compensation method based on the internal channel current regulation. This method involves precise adjustment of the three-channel currents at the channel switching point to effectively compensate for wavelength errors and resolve the wavelength hopping issue.

The experimental results demonstrated a logarithmic relationship between switching frequency and wavelength deviation. By fitting the experimental data, we derived a relationship formula for wavelength deviation concerning switching frequency. Further experimental validation showed that by compensating for the three-channel currents at the channel switching point, wavelength errors were reduced to within 1 pm, indicating a significant improvement in performance.

Consequently, this compensation method led to a substantial reduction in wavelength deviation, enhancing the wavelength stability of the MG-Y laser. The article not only fills the technical gap in the field of optical fiber sensing demodulation systems under high-speed vibration environments in theory, but also directly contributes to enhancing the country's core competitiveness in the aerospace equipment sector, with large scientific and application value.