Confocal Raman Microscopy with Adaptive Optics

Confocal Raman microscopy,\na highly specific and label-free technique\nfor the microscale study of thick samples, often presents difficulties\ndue to weak Raman signals. Inhomogeneous samples introduce wavefront\naberrations that further reduce these signals, requiring even longer\nacquisition times. In this study, we introduce Adaptive Optics to\nconfocal Raman microscopy for the first time to counteract such aberrations,\nsignificantly increasing the Raman signal and image quality. The method\nis designed to integrate seamlessly with existing commercial microscopes\nwithout hardware modifications. It uses a wavefront sensorless approach\nto measure aberrations using an optofluidic, transmissive spatial\nlight modulator that can be attached to the microscope nosepiece.\nOur experimental results demonstrate the compensation of aberrations\ncaused by artificial scatterers and mouse brain tissue, improving\nspatial resolution and achieving up to 3.5-fold signal enhancements.\nOur results provide a basis for the molecular label-free study of\nbiological systems at greater imaging depths.