Nonlinear fibre laser sources for advanced endoscopic imaging

A key issue hindering the translation of advanced microscopy techniques such as multiphoton microscopy into clinical settings is the current reliance on very expensive and complex ultrafast solid-state lasers. Multiphoton microscopy requires highly intense pulses of light at wavelengths in the near-infrared to excite biological molecules via multiphoton absorption, which to date can only be provided by Ti:sapphire lasers. Fibre lasers, widely used in industrial materials processing applications, have a number of practical advantages over solid-state lasers that make them well suited to deployment in clinical environments e.g. hospitals. However, the standard emission wavelengths of fibre lasers are not suitable for multiphoton excitation of biological molecules that are of interest for disease diagnosis.
In this project, a novel wavelength-versatile ultrafast fibre laser that uses nonlinear wavelength conversion in a photonic crystal fibre (PCF) we be developed specifically for this application. The PCF will be interfaced with an endoscopic probe-a highly miniaturised version of a table-top multiphoton microscope-that will be designed to be inserted into the working channel of existing clinical endoscopes. The goal is to develop a clinically deployable multiphoton endoscopic instrument by seamlessly integrating the ultrafast fibre laser with the endoscopic probe, using the PCF that modifies the emission wavelength to suit multiphoton excitation of biological tissue.