Fast InfraRed Coherent HARmonic Microscopy
Advanced multiphoton microscopy for deeper and faster biomedical imaging
The development of new therapeutic strategies for different types of diseases requires specialized instruments capable of capturing biological problems in their entirety by imaging them at all relevant length and time scales. The EU-funded FAIR CHARM project aims to provide two imaging solutions, SWIM and SLIDE. Both have the ability to detect and image biological processes and their cellular and extracellular structures involved in disease onset and progression in real time. While the SWIM microscope uses novel laser sources in the infrared wavelength range around 1700 nm to penetrate deeper into biological tissues, the SLIDE microscope pushes the boundaries of fast multiphoton microscopy to detection rates in excess of several thousand per second.
The principle of SLIDE microscopy is based on spectral and temporal excitation of the sample, combined with detection by high bandwidth (GHz) photodetectors. A Fourier domain mode-locked (FDML) laser serves as swept source. Using a fast electro-optic modulator (EOM), short pulses are generated (temporal excitation). These pulses are amplified and spectrally resolved using a diffraction grating (spectral excitation). To measure an area, the y-axis is scanned using a galvanometric scanner. Through this technique, each pulse has both a unique wavelength and a unique time (spectro-temporal encoding), resulting in sequential and pixel-by-pixel illumination. The fluorescence signals generated in the sample are recorded and analysed with high acquisition bandwidth.
Within the project, MLL realizes a SLIDE prototype based on the current research results of the Institute of Biomedical Optics, University of Lübeck, which will be used in different European Universities. The different scientific results of the different disciplines will be used to improve the SLIDE technology and will be directly implemented in an improved prototype.