Wavelength drift suppression in high-precision fiber optic spectrometers based on torsional-distortion-type chaotic waveguides.

To address the issue of wavelength drift caused by non-uniform light field distribution in high-resolution fiber spectrometers, this paper proposes a chaotic waveguide scheme based on a "double-fiber helical twist" non-axisymmetric topological structure. The effectiveness of this structure in homogenizing the light field was verified through a combination of simulations and experiments. The results demonstrate that this scheme can reconstruct an extremely eccentric light field into a uniform super-Gaussian distribution. Under perturbations such as optical axis misalignment, wavelength drift is successfully suppressed within the limit of resolution (<0.1 nm), and the spot center of mass remains stable. This confirms that the deterministic geometric structure scheme possesses excellent robustness, providing an efficient, passive, and engineered solution for high-precision spectral analysis.