All-fiber frequency agile triple-frequency comb light source.

Tricomb spectroscopy unveils a new dimension to standard linear and nonlinear spectroscopic analysis, offering the possibility to reveal the almost real-time evolution of complex systems with unprecedented accuracy. Current triple comb configurations are based on the use of mode-locked lasers, which impose constraints on the comb parameters, and require complex electronic synchronization, thus limiting potential applications. In this paper, we present the experimental demonstration of a new type of all-fiber, self-phase-locked, frequency-agile tri-comb light source.

Coexistence of gain-through-filtering and parametric instability in a fiber ring cavity.

We experimentally and numerically investigate the dynamics of a fiber ring cavity in which two different instability can be excited: gain-through-filtering and parametric instability. We demonstrate that they can be triggered individually or collectively depending on the two main control parameters offered by the cavity, namely the pump power and the cavity detuning. The experimental observations are in good agreement with numerical simulations.

Measurement of the nonlinear parametric instability gain in dispersion oscillating fibers.

We report the observation of the parametric gain band distortion in the nonlinear (depleted) regime of modulation instability in dispersion oscillating fibers. We show that the maximum gain is shifted even outside the boundaries of the linear parametric gain band. Experimental observations are confirmed by numerical simulations.

Mid-infrared difference-frequency generation directly pumped by a fiber four-wave mixing source.

We demonstrate a new, to the best of our knowledge, method of generating mid-infrared pulses by difference frequency mixing the Stokes pulse generated by four-wave mixing in a photonic crystal fiber with the remaining pump pulse. The Stokes pulses generated by four-wave mixing are inherently overlapped temporally and spatially with the pump pulse at the output of the fiber. Focusing this output into a nonlinear crystal phase matched for difference frequency generation between the pump and Stokes pulses results in a simple method of generating mid-infrared pulses.

Label-free highly multimodal nonlinear endoscope.

We demonstrate a 2 mm diameter highly multimodal nonlinear micro-endoscope allowing label-free imaging of biological tissues. The endoscope performs multiphoton fluorescence (3-photon, 2-photon), harmonic generation (second-SHG and third-THG) and coherent anti-Stokes Raman scattering (CARS) imaging over a field of view of 200 µm. The micro-endoscope is based on a double-clad antiresonant hollow core fiber featuring a high transmission window (850 nm to 1800 nm) that is functionalized with a short piece of graded-index (GRIN) fiber.