This paper experimentally investigates the first-harmonic stability of a vibration-modulated fiber cantilever accelerometer. A real-time digital processing system based on an MCU is established, and a cantilever probe is fabricated with an improved glue dispensing step at the cantilever root to enhance the stability of the fixed end. Measured photodetector signals confirm that the operating point remains near the center of the optical intensity curve, although a zero-point deviation would exist in practice. The observed waveforms agree well with theoretical analysis. Sensitivity tests using the gravity field tumbling method yield sensitivities of 0.031665 V/g and 0.043236 V/g for modulation amplitudes of 58 V and 100 V peak-to-peak, respectively, demonstrating that sensitivity increases with modulation amplitude, consistent with theoretical predictions. Long-term zero-acceleration tests over 3600 s and Allan deviation analysis show that the velocity random walk and bias instability improve from 8.3 × 10−3 g/ Hz and 2.1 × 10−3 g (at 58 V modulation) to 5.6 × 10−3 g/ Hz and 1.3 × 10−3 g (at 100 V modulation). To the best of our knowledge, the achieved bias instability of 1.3 × 10−3 g is the first reported result for this type of accelerometer under long-term testing. These findings provide a valuable reference for further development, including the incorporation of second- and fourth-harmonic demodulation for enhanced performance.
Aiming at the problem that the multiple scattering effects affect the time-domain characteristics of the received signal when the pulsed laser is transmitted in the snowfall environment, a Monte Carlo multiple scattering transmission model based on the collision probability is established to numerically simulate the multiple scattering effects of the snow particle swarm. To investigate the time-domain characteristics of pulsed lasers after transmission in snowfall environments, a time-domain analysis model based on EMG is established. The influence of transmission distance, emission pulse width, and asymmetry factor on the delay and broadening of the received signal pulse is analyzed. To verify the model, an experimental measurement platform for the time-domain characteristics of pulsed lasers is constructed. Both experimental and simulation results indicate that pulse delay and broadening increase with increasing transmission distance, and when the transmission distance remains constant, pulse delay and broadening increase with increasing snowfall rate in three snowfall conditions: 0< SR < 1, 1 < SR < 2, and 2 < SR < 3. The relative error between experimental data and simulation results is consistently below 5%, fully validating the model's ability to effectively simulate the impact of snowfall multiple scattering effects on the time-domain characteristics of pulsed lasers. This research provides a theoretical basis for designing time-domain compensation algorithms for optical transmission systems in snowy environments.
