Conference Agenda

Recent progress in Cr²⁺:ZnS waveguide lasers demonstrates laser amplification, frequency comb generation, and nonlinear conversion, targeting a miniaturized, ultra-stable comb spanning visible (<600 nm) to mid-IR (>5 μm) with intrinsic support for f–2f, 2f–3f, and related stabilization schemes. This requires balancing mode quality, amplification (up to 75× at 2.35 W output in CPA regime), and spectral broadening.

The most attractive feature of the laser-written waveguides is that they enhance fs-pulse nonlinear interactions in non-centrosymmetric Cr:ZnS, enabling harmonic generation and controlled broadening. Combined theory and experiment allow precise tuning of gain versus nonlinear effects for robust CPA stabilization. LMA waveguides with graded diameter and NA integrate high-gain amplification and χ²/χ³ broadening in a single structure, preserving beam quality via multimode-to-fundamental mode condensation, enabling monolithic multi-octave mid-IR combs.

Looking into the future, the recent game-changing results lay the groundwork to explore integrated ultrafast laser potential directly in the mid-IR for various real-life applications, including sub-wavelength 3D-material processing, 3D-printing as well as quantum enhanced fine molecular sensing and imaging.

We present a compact pulse post-compression setup based on two consecutive bulk multi-pass cells. The input pulses of 220 fs are first compressed to 50 fs in the first stage and then to 6 fs in the second stage, corresponding to 1.7 optical cycles at 1039 nm.

We report the first demonstration of induced modulational instability (MI) in a gas-filled hollow-core fiber (HCF). By co-injecting 220 fs pump pulses at 1030 nm with a weak coherent supercontinuum seed into an argon-filled HCF, we achieve flexible control over the MI dynamics by tuning the relative delay. The resulting output spans a PHz-broad bandwidth extending from the infrared to the deep-ultraviolet (down to 250 nm). We show that the sideband spacing and spectral extension are continuously tunable, and single-shot measurements confirm the high coherence and stability of the process. These results establish gas-filled HCFs as a powerful platform for coherent broadband light generation and ultrashort waveform shaping in regimes inaccessible to solid-core waveguides.

We present an analytical and numerical description of the Q-switching instability of modelocked pulse trains (QSML instability) within a dynamical master-equation (ME) framework. In the experimentally relevant limit where the pulse duration is much shorter than the material recovery times, we derive a compact instability criterion that accurately predicts the transition from continuous-wave modelocking to QSML at low saturation levels, corresponding to the influential sech-pulse solution derived by Haus. Crucially, the ME captures this instability within a general framework while enabling direct simulations of the full dynamics, including the characteristic long-period modulation of pulse energies over many roundtrips. Analytical predictions and numerical results are in excellent agreement, establishing a consistent description of QSML across laser platforms.

We study how the temporal coherent quality of input pulse influences supercontinuum generation properties in polarization-maintaining, all-normal-dispersion fibers. We demonstrate how factors such as pump duration, imperfections in spectral amplitude and phase, and the presence of satellite pulses are mapped in the supercontinuum spectrum. Meanwhile, stochastic phase noise and intensity-to-phase transfer coefficients are shown to exhibit an inherently deterministic behavior.