Absorption modulation based non-linear structured illumination microscopy

We propose a novel super-resolution microscopy technique, absorption modulation-based nonlinear structured illumination microscopy (AM-NLSIM), by utilizing the photochromic properties of a material. In the proposed technique, dual-wavelength sinusoidal illumination interacts with a layer of photochromic molecules referred to as an absorption modulation layer. This interaction generates a non-linear illumination pattern encoding additional high-frequency components within the system’s passband. We present the theoretical foundation of AM-NLSIM, supported by numerical simulations. The simulation is performed on different samples, where the captured Moiré frames undergo a blind reconstruction approach tailored for non-linear SIM. The simulation demonstrates the utility of AM-NLSIM to achieve sub-50 nm resolution while maintaining the practicality of conventional linear SIM, i.e. using low-intensity, continuous-wave lasers and standard fluorophores.