Fig. 6: Demonstration of controllable detection precision.
From: Precise detection of tiny birefringence with accuracy reaching 10−11 level
The tunable detection precision can be achieved by carefully varying the BG envelope width or crystal coupling length. a The experimentally obtained detection precision as a function of envelope parameter r0, for two different coupling lengths: L = 180 μm (red line) and L = 240 μm (blue line). Based on these data, we can reasonably separate the detection precision into regions I and II, where the sensitivity (curve slope) to the envelope parameter is measured as 1.44 × 10−11 nm−1 and 2.59 × 10−12 nm−1, respectively. Values of experimental data in (a) are fitting plus s.e.m (10%). b Difference between detection precisions obtained by these two different coupling lengths. c, d Experimentally recorded spherical-wave interference patterns at the output end of the crystal: c without birefringence modulation and d, with a tiny birefringence (Δn = 2.38 × 10−10 ± 7.04 × 10−12). e, f The simulations corresponding to the experiments c and d. c–f Share the same scale with scale bar being 10 μm.
