Enhancing Fluorescence Detection Sensitivity

摘要

Destructive interference greatly improves the signal-to-noise ratio of fluorescence detection based on stimulated emission, and thus decreases the detection dye concentration limit. We established SE-based detection in long-working-distance settings by implementing pump-probe method with lock-in detection and destructive interference. Results show that we were able to achieve 10 times intensity ratio decrease in the probe beam with destructive interference, which corresponds to 10 times decrease of concentration detection limit. We are now developing the technique's potential for high-resolution 3D biological imaging by stimulated emission optical coherence tomography (SE-OCT), using SE fluorescence as a viable and unique contrast.