Structured light-assisted wavefront shaping for enhanced and precise sensing

The scattering of light by biological tissues impedes optical methods like fluorescence imaging and microscopy. These techniques are limited in such turbid media by their inability to penetrate deeper when utilizing only non-scattered or ballistic photons and maintain signal clarity. Wavefront shaping methods present a promising solution to reverse the scattering effects by manipulating the fundamental properties of light. Here, we demonstrate that substituting the traditional Gaussian beams with non-diffracting Bessel-Gauss (BG) beams as input for wavefront shaping allows for more precise localization, deeper penetration and higher enhancement of signal. We utilized a simple imaging platform with a spatial light modulator (SLM) to compare the performance of Gaussian and BG beams across various scattering media, including pig skin, parafilm, and yogurt. Initially, we created a single focus through scattering media using both beams. Subsequently, we optimized a fluorescent target hidden by scattering media. Results from both experiments showed that BG beam achieved higher enhancement compared to the Gaussian beam. Additionally, we demonstrated simultaneous optimization of multiple fluorescent targets through wavefront shaping with both beams. BG beams not only achieved higher enhancement of the hidden targets but also revealed targets that remained obscured with Gaussian beam optimization. The superior performance of wavefront shaping with BG beams highlights their potential for advancing optical imaging methods for biomedical diagnostics and research.