Optimizing surface plasmon resonance spectral imaging through AOTF-calibrated light sources and image feedback

The resonance curve signal obtained by spectral imaging of surface plasmon resonance (SPR) is modulated by the light source spectrum, resulting in errors in the measurement of resonance value and the increase of calculation time, making it difficult to achieve real-time SPR wavelength imaging with high linearity. Here we adjust the acousto-optic tunable filter (AOTF) amplitude by image feedback to achieve real-time uniform calibration of the light source spectrum. As a result, the stability of the light source can be largely increased, which favors long-time detection. Furthermore, we propose a data processing method to achieve high linearity and realize real-time spectral imaging under fast scanning conditions. The calculation time of a single image is as low as 600 ms, with a linearity R2 of 0.9931. More importantly, the dynamic range is increased by 20 nm, which broadens the application scenarios.