"Next generation mid-infrared frequency comb lasers: recent progress and opportunities" (Prof. Irina Sorokina)

Datum: 12.05.2026
Uhrzeit: 14:30
Vortragende(r): Prof. Irina Sorokina
Norwegian University of Science and Technology, Trondheim, Norway
Ort: Max Planck Institute of Quantum Optics, Hans-Kopferman-Straße 1, 85748 Garching
Raum: Herbert Walther Lecture Hall
Gastgeber: MPQ

The talk reviews the recent works of the Laser Physics Group at NTNU on femtosecond waveguide lasers operating in the mid-IR wavelength range above 2 microns, as well as the implications this class of lasers may have for real-world applications and for future research, including quantum technologies. Recent progress in Cr²⁺:ZnS waveguides 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, and spectral broadening.

The most interesting 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 for sub-wavelength 3D-material processing as well as fine molecular sensing and imaging.