Dynamic range expansion algorithms for Shack-Hartmann wavefront sensor in aspheric lens surface quality assessment

Injection-molded aspherical lenses in mobile phone cameras exhibit significant wavefront aberrations that often exceed the measurement dynamic range of conventional Shack-Hartmann wavefront sensors (SHWFS). This study investigates three algorithms for extending SHWFS dynamic range: the sorting method, iterative extrapolation method, and adaptive spot matching method. A brightness stratification technique was implemented to address non-uniform spot intensity distributions. Numerical simulations evaluated computational efficiency, stability, and measurable dynamic range across typical Zernike aberration terms. Results demonstrate that the sorting method achieves superior computational efficiency (2 ms processing time) with 100% convergence reliability, outperforming other methods by orders of magnitude. However, both iterative extrapolation and adaptive spot matching methods provide substantially larger dynamic ranges, measuring aberration RMS values 2~5 times higher than the sorting method. The adaptive spot matching method exhibits 96% convergence success rate with timing variations due to optimization randomness.