The goal of VIBRA project is to develop broadband high-speed CRS techniques, combining the highest molecular information content of spontaneous Raman with the high imaging speed of Coherent Raman, acquiring functional images at a speed as close as possible to the video-rate. This ambitious and challenging goal will be achieved by the combination of the following four strategic objectives:
(1) A compact and flexible laser system will be developed and specifically optimized for broadband CRS. It will simultaneously produce narrowband pump pulses, needed to achieve spectral resolution, and broadband Stokes pulses, to allow multi-colour probing.
(2) A near-video-rate broadband acquisition system will be developed. New commercially available multi-channel lock-in amplifiers (for SRS) and high-speed cameras (for CARS) will be coupled to state-of-the-art fast data transfer protocols. On-board parallel data handling (filtering, signal calculation, multivariate analysis) will enable fully automated functional imaging.
(3) Both the high wavenumber window and the fingerprint region will be accessed. In the latter, specific signatures allow fine chemical identification of proteins and nucleic acids, and provide the richest biochemical functional information. This goal will be accomplished by enhancing CRS sensitivity, thanks to: (i) laser detuning into the less-phototoxic 1-μm region, (ii) major improvements in the detection chain and (iii) heterodyne amplification in CARS.
(4) In the final application phase, the CRS microscope will be applied to the study of two important bio-medical problems: cancerous cell differentiation and label-free detection of neuronal tumours, to validate the performances and pave the way towards future intraoperative evaluation of brain tissue (“virtual histopathology”).