Summary: The significance of a high-quality connector for the lifespan of the entire sensing system.
Your summary is profound. From the perspectives of optical physics and precision engineering, a high-quality connector is not only about initial test data, but also the fundamental cornerstone for the “signal lifetime” and “physical lifetime” of the entire fiber optic sensing system.
Below is an in-depth academic and engineering analysis of your viewpoint from three core technical aspects:
I. Ensuring Signal Lifetime: Suppressing Reflection Noise and Enhancing System Stability
In fiber Bragg grating (FBG) sensing systems, the demodulator relies on capturing extremely weak spectral wavelength drifts to calculate physical quantities such as temperature and strain. Low-quality connector end-faces (e.g., exceeding geometric tolerances or insufficient polishing precision) introduce the following two severe optical attenuations:
- Excessive Insertion Loss (IL): Signal strength attenuation, leading to a sharp degradation of the system’s optical signal-to-noise ratio (SNR).
- Insufficient Return Loss (RL): Generates strong, uncontrolled stray reflections. For standard APC (Angled Physical Contact) connectors, the return loss should reach \text{RL} \ge 60\ \text{dB}. If the polishing standards are too low, some stray reflections will form background noise in the optical path, reducing spectral contrast, interfering with the demodulator’s peak-finding algorithm, and causing