Graphene-syncronized coherent Raman scattering laser and microscope

ended

The current standard of tumour diagnostics is histopathology, where excisions are taken from the tissue of a diseased patient, followed by staining and visual inspection. The process is time-consuming, costly, with low sensitivity and specificity. The results are subjective and qualitative, heavily depending on the judgement of the doctor. Spontaneous Raman microscopy is a label-free and non-invasive imaging technique, which enables to obtain objective and quantitative information on the tissue, by measuring its detailed molecular composition. It has proven capability to discriminate between healthy and tumour tissue and to identify the type and grade of tumour. Its main drawback is the very weak Raman signal, resulting in slow acquisition speed. This means that acquisition of a complete image would take up to several hours, prohibiting real-time and in vivo imaging. Coherent Raman scattering (CRS) generates the signal from a coherent superposition of the molecules in the tissue, illuminated by two synchronized ultrashort light pulses of different colour, thus improving by several orders of magnitude the acquisition speed. This enables real-time, in vivo imaging of the tissue allowing doctors to make informed diagnostic and/or therapeutic decisions immediately. The main hurdle of CRS microscopy, which has prevented its widespread adoption in a clinical setting, is the complexity and the high cost of the illuminating laser system, which is bulky and requires handling by specialized personnel. GSYNCOR aims to drastically simplify the laser system used for CRS microscopy, increasing its reliability and reducing its cost by exploiting the ultrafast and broadband nonlinear optical response of graphene. This enables not only pulsed (mode-locked) operation of a laser system, but also to passively synchronize two different lasers, generating the dual-wavelength pulses required for CRS. This will enable the uptake of CRS as a disruptive biomedical imaging technology.