VAMPIRE microscopy enables fast and simultaneous structural, metabolic, and chemical characterization of living tissues label-free

We present a completely label-free technology that captures eight complementary contrasts describing the metabolic, chemical, structural, and dynamic profiles of the tissue microenvironment with a single laser source, called VAMPIRE (Versatile Autofluorescence lifetime imaging, Multiharmonic generation, Polarization-sensitive Interferometry, and Raman scattering in Epi-detection) microscopy. VAMPIRE microscopy maximizes the spectral utility of light-matter interactions by creating four nonlinear (second harmonic generation, two-channel two-photon fluorescence, coherent Raman scattering) and two linear interactions (backscattering, birefringence) simultaneously with a single laser. Innovations in each modality improved the overall speed and sensitivity. Fast fluorescence lifetime imaging microscopy (FLIM) was accelerated with our computational photon counting algorithm called single-and-multi photon peak event detection (SPEED), capable of counting up to 250% photon rates. Dual-channel fast two-photon FLIM was achieved by compressed sensing of analog photocurrents on a field-programmable gate array on board the digitizer. We developed a new and faster method for hyperspectral coherent Raman microscopy using supercontinuum generation and custom pulse shapers, which facilitated rapid tuning to desired vibrational states. Polarization multiplexing in optical coherence imaging enabled compressed sensing of birefringence. Finally, computational approaches to maximize the information from these complementary contrasts yielded new insights into the processes within the tissue microenvironment. VAMPIRE microscopy is the nexus of label-free microscopy research, advances in optoelectronic technologies, and our innovations in computational and multimodal imaging for diverse applications.