Publication: Wavelength dependent characterization of a fibre endoscope

As multimode fibre endoscopy has matured to a state that they could be used in resolving actual research questions it is crucial that parameters that affect the imaging quality are investigated.
For multi-photon imaging, it is necessary to know the endoscope bandwidth and have a complete characterization of the laser pulse (spectral amplitude and phase) at the sample plane, to control the pulse length, which needs to be short for 2-photon fluorescence and long and with a linear chirp for CARS. In this paper we demonstrate that despite the use of complicated adaptive optics, for GRIN fibres, the spectral phase is quadratic and does not vary across the fibre facet. Thus the most appropriate pulse compression method is a standard pulse compressor. We also show that if the excitation wavelength needs to be tuned, it is necessary to compensate for the dispersion of the SLM to fully utilize the fibre bandwidth.

http://dx.doi.org/10.1364/OE.27.028239