Dynamic visualization of the photorefractive effect via single-pixel complex-amplitude imaging

We demonstrate the dynamic visualization of the photorefractive effect in an iron-doped lithium niobate crystal using single-pixel complex-amplitude imaging (SPCI). A 532 nm Gaussian beam locally pumps the crystal, while a uniform 632.8 nm illumination probes the photoinduced refractive index changes. Benefiting from its common-path self-referencing architecture, SPCI exhibits strong environmental robustness compared to traditional interferometry, enabling stable, continuous observation of refractive index evolution over extended periods. Our experimental results clearly resolve the spatial anisotropy and temporal progression of the photorefractive effect, further revealing a distinct polarization-dependent saturation behavior. This approach provides direct experimental access to underlying photorefractive dynamics, facilitating both fundamental understanding and device optimization.