EUROPHOTON 2022

We present a post compression of a thulium-doped fiber laser output in a hollow-core fiber, delivering 100W average power, 1mJ pulse energy and 17.6fs pulse duration at 100kHz repetition rate. It is, to the best of our knowledge, the highest average-power mJ-class few-cycle source in the SWIR reported.

We present a pulsed polarization-maintaining all-in-fiber MOPA setup based on Ho3+ and Tm3+ -doped silica fibers. By pumping a ZGP OPO an mid-IR output power of 8.1 W and a conversion efficiency of 44 % (slope 61 %) is obtained. M² factors of 2.2 (signal) and 2.0 (idler) are determined at maximum power.

We present our recent results in high-power laser emission from 2.1 to 2.2 µm, introducing the 79X nm pumped Tm3+:Ho3+ -codoped silica fiber laser as serious alternative when it comes to power scaling within this wavelength region. In particular, a record power of 145 W has been achieved at 2.2 µm.

We report on the generation of up to 12 nJ pulse energy with a compressed pulse duration of 156 fs by an ultrafast thulium-doped fiber Mamyshev oscillator. The oscillator incorporated double-clad fibers to provide a sufficient amplification with a high suppression of amplified spontaneous emission of 22 dB.

We present a high-power, highly efficient thulium-doped fiber amplifier which is cladding-pumped at 1692 nm. For the first time, a Tm-doped fiber suitable for ultrafast operation with considerable pulse energies provides slope efficiencies around 80% with 58 W output power. Using commercially available pump sources, this approach is highly scalable.

A simple method is presented for determining the quantum efficiency and back-ground core propagation loss in Thulium (Tm)-doped fibre lasers. Since the overall laser efficiency is typically limited by one of these two parameters, quantitatively determining their individual contributions is vital to informing the development of future Tm-doped fibres.

We present our latest results in power scaling in the 2 $\mu$m region. The all-fiber laser system is a simple MOPA configuration composed of a seed laser and a high power amplifier. More than 900 W of output power at 2036 nm are demonstrated with a diffraction limited beam quality.