GeO(2)-doped-core photonic crystal fibers show greatly enhanced Kerr and Raman responses with respect to pure silica without any significant modification of the group-velocity dispersion curve. We show that such fibers allow a significant improvement of cw-pumped supercontinuum generation. We report for the first time to our knowledge the generation of a white-light cw-pumped supercontinuum spanning from 470 nm to more than 1750 nm.

The lensless endoscope represents the ultimate limit in miniaturization of imaging tools: an image can be transmitted through a (multi-mode or multi-core) fiber by numerical or physical inversion of the fiber's premeasured transmission matrix. However, the transmission matrix changes completely with only minute conformational changes of the fiber, which has so far limited lensless endoscopes to fibers that must be kept static. In this letter we report for the first time a lensless endoscope which is exempt from the requirement of static fiber by designing and employing a custom-designed conformationally invariant fiber. We give experimental and theoretical validations and determine the parameter space over which the invariance is maintained.

We report two-photon lensless imaging through a novel Fermat's golden spiral multicore fiber. This unique layout optimizes the sidelobe levels, field of view, crosstalk, group delay, and mode density to achieve a sidelobe contrast of at least 10.9 dB. We demonstrate experimentally the ability to generate and scan a focal point with femtosecond pulses and perform two-photon imaging.

We report the fabrication and characterization of the first double clad tubular antiresonant hollow core fiber. It allows to deliver ultrashort pulses without temporal nor spectral distortions in the 700-1000 nm wavelength range and to efficiently collect scattered light in a high numerical aperture double clad. The output fiber mode is shaped with a silica microsphere generating a photonic nanojet, making it well suitable for nonlinear microendoscopy application. Additionally, we provide an open access software allowing to find optimal drawing parameters for the fabrication of tubular hollow core fibers.