Sub-30-fs Yb:CALGO laser oscillator based on cross-polarized multi-mode diode pumping.

Ytterbium (Yb)-doped materials are an excellent choice for efficient and powerful ultrafast lasers. They exhibit favorable emission properties, which include a low quantum defect and compatibility with cost-effective high-power pump diodes. While being strongly beneficial for efficiency, the low quantum defect is a challenge for operation in the few-cycle regime.

Efficient XUV-light out-coupling of intra-cavity high harmonics by a coated grazing-incidence plate.

We experimentally demonstrate an efficient and broadband extreme-ultraviolet light (XUV) out-coupling mechanism of intra-cavity generated high harmonics. The mechanism is based on a coated grazing-incidence plate (GIP), which utilizes the enhanced reflectivity of s-polarized light in comparison to p-polarized light for large angles of incidence (AoI). We design and produce a 60°-AoI coated GIP, tailored specifically for the high demands inside a sub-50-fs Kerr-lens mode-locked Yb:YAG thin-disk laser oscillator in which high harmonic generation (HHG) is driven at ∼450 MW peak power and 17 MHz repetition rate.

Sub-30-fs Yb:YAG thin-disk laser oscillator operating in the strongly self-phase modulation broadened regime.

We experimentally investigate the limits of pulse duration in a Kerr-lens mode-locked Yb:YAG thin-disk laser (TDL) oscillator. Thanks to its excellent mechanical and optical properties, Yb:YAG is one of the most used gain materials for continuous-wave and pulsed TDLs. In mode-locked operation, its 8-nm wide gain bandwidth only directly supports pulses with a minimum duration of approximately 140 fs.

Intra-oscillator broadband THz generation in a compact ultrafast diode-pumped solid-state laser.

We demonstrate broadband and powerful terahertz (THz) generation at megahertz repetition rate based on intra-oscillator optical rectification (OR) in gallium phosphide (GaP). By placing the nonlinear crystal directly inside the cavity of a Kerr-lens mode-locked ultrafast diode-pumped solid-state laser (DPSSL) oscillator, we demonstrate a compact and single-stage THz source. Using only 7 W of diode-pump power, we drive OR in a GaP crystal with 22 W of average power at ∼80 MHz repetition rate.

High-power dual-comb thin-disk laser oscillator for fast high-resolution spectroscopy.

Free-running dual-comb systems based on a single laser cavity are an attractive next generation technology for a wide variety of applications. The high average power achievable by dual-comb thin-disk laser (TDL) oscillators make this technology especially attractive for spectroscopy and sensing applications in the molecular fingerprint region enabled by nonlinear frequency conversion. However, the high noise levels of TDL oscillators, e.

Intra-oscillator high harmonic generation in a thin-disk laser operating in the 100-fs regime.

We demonstrate that Kerr lens modelocking is well-suited for operating an ultrafast thin-disk laser with intra-oscillator high harmonic generation (HHG) in the 100-fs pulse duration regime. Exploiting nearly the full emission bandwidth of the gain material Yb:YAG, we generate 105-fs pulses with an intracavity peak power of 365 MW and an intracavity average power of 470 W. We drive HHG in argon with a peak intensity of ∼7⋅10 W/cm at a repetition rate of 11 MHz.

Sub-100-fs Kerr lens mode-locked Yb:LuO thin-disk laser oscillator operating at 21 W average power.

We investigate power-scaling of a Kerr lens mode-locked (KLM) Yb:LuO thin-disk laser (TDL) oscillator operating in the sub-100-fs pulse duration regime. Employing a scheme with higher round-trip gain by increasing the number of passes through the thin-disk gain element, we increase the average power by a factor of two and the optical-to-optical efficiency by a factor of almost three compared to our previous sub-100-fs mode-locking results. The oscillator generates pulses with a duration of 95 fs at 21.

Broadband terahertz pulse generation driven by an ultrafast thin-disk laser oscillator.

We demonstrate broadband THz generation driven by an ultrafast thin-disk laser (TDL) oscillator. By optical rectification of 50-fs pulses at 61 MHz repetition rate in a collinear geometry in crystalline GaP, THz radiation with a central frequency at around 3.4 THz and a spectrum extending from below 1 THz to nearly 7 THz are generated.

Laser-assisted morphing of complex three dimensional objects.

Morphing refers to the smooth transition from a specific shape into another one, in which the initial and final shapes can be significantly different. A typical illustration is to turn a cube into a sphere by continuous change of shape curvatures. Here, we demonstrate a process of laser-induced morphing, driven by surface tension and thermally-controlled viscosity.