In-band pumped, Q-switched thulium-doped fiber laser system delivering 140 W and 7 mJ pulse energy.

We report on a highly efficient, in-band pumped, Q-switched, Tm-doped, rod-type master oscillator power amplifier (MOPA) system delivering up to 140 W average output power and 7 mJ pulse energy with a slope efficiency of 77% at 20 kHz repetition rate. The amplifier is pumped with Raman-shifted fiber lasers centered at 1692 nm. This in-band pump scheme for Tm-doped fiber lasers can significantly mitigate their quantum defect-related heat load limitations.

High-power two-color plasma-based THz generation driven by a Tm-doped fiber laser.

We report on the efficient generation of broadband THz radiation based on a two-color gas-plasma scheme. Broadband THz pulses covering the whole THz spectral region, from 0.1-35 THz, are generated.

Nonlinear pulse compression to sub-two-cycle, 1.3 mJ pulses at 1.9 μm wavelength with 132 W average power.

We report the nonlinear pulse compression of a high-power, thulium-doped fiber laser system using a gas-filled hollow-core fiber. The sub-two cycle source delivers 1.3 mJ pulse energy with 80 GW peak power at a central wavelength of 1.

Inband-pumped, high-power thulium-doped fiber amplifiers for an ultrafast pulsed operation.

We investigate the influence of the pump wavelength on the high-power amplification of large-mode area, thulium-doped fibers which are suitable for an ultrashort pulsed operation in the 2 µm wavelength region. By pumping a standard, commercially available photonic crystal fiber in an amplifier configuration at 1692 nm, a slope efficiency of 80 % at an average output power of 60 W could be shown. With the help of simulations we investigate the effect of cross-relaxations on the efficiency and the thermal behavior.

Ultrafast Tm-doped fiber laser system delivering 1.65-mJ, sub-100-fs pulses at a 100-kHz repetition rate.

High-energy, ultrafast, short-wavelength infrared laser sources with high average power are important tools for industrial and scientific applications. Through the coherent combination of four ultrafast thulium-doped rod-type fiber amplifiers, we demonstrate a Tm-doped chirped pulse amplification system with a compressed pulse energy of 1.65 mJ and 167 W of average output power at a repetition rate of 101 kHz.

Compact, diode-pumped, unstable cavity Yb:YAG laser and its application in laser shock peening.

We present the setup of a compact, q-switched, cryogenically cooled Yb:YAG laser, which is capable of producing over 1 J output energy in a 10 ns pulse at 10 Hz. The system's design is based on the recently published unstable cavity layout with gain shaping of the spatial intra-cavity intensity distribution. Using a hexagonal homogenized pump beam, the laser generated an according hexagonal output beam profile.