FIP Seminar: Understanding Surprises in Nonlinear Microscopy: Unexpected Complexity Creates Useful Contrast

Understanding Surprises in Nonlinear Microscopy: Unexpected Complexity Creates Useful Contrast

Nonlinear microscopy can detect molecular signatures that are fundamentally different (and in many cases more useful) than what is found using conventional microscopes. Our lab has made technological advances that allow excellent signals with very low average laser powers (far less than a laser pointer) that avoid damage, even in very sensitive samples. Here we will focus on two specific applications that demand such care: detecting molecular anomalies in melanoma specimens that indicate metastatic cancer before it is clinically obvious, and understanding historically important pigments in cultural heritage objects. In both cases, the remarkable complexity in the nonlinear pump-probe signals, due to many different mechanisms, makes it possible to distinguish chromophores that look identical by traditional means. I will discuss new approaches that separate the different signal contributions by physical mechanism, thus better separating useful contrast from background. This has the potential to significantly reduce melanoma mortality, and the potential to detect early signs of degradation in artwork before they manifest in visual distortions.