Two-photon laser scanning fluorescence microscopy using photonic crystal fibre

We report the application of a simple yet powerful modular pulse compression system, based on photonic crystal fibres which improves upon incumbent twophoton laser scanning fluorescence microscopy techniques. This system provided more than a 7-fold increase in fluorescence yield when compared with a commercial two-photon microscopy system. From this, we infer pulses of infrared radiaton of less than 35 fs duration reaching the sample