Thin-disk laser system operating above 10  kW at near fundamental mode beam quality

Abstract

We report on a thin-disk laser system with more than 10 kW of output power and a beam quality of M 2 = 1.76 at an overall optical-to-optical efficiency of 51%. The system consists of two thin-disk laser oscillators and a thin-disk multi-pass amplifier system. To reach high output powers while maintaining good beam quality, the output beams of two identical laser oscillators are polarization-combined. Subsequently, the beam is amplified in a multi-pass system. To the best of our knowledge, this is the highest output power achieved for a thin-disk laser system with a beam quality close to fundamental mode.

Ultra-Short Pulse Lasers for Microfabrication: A Review

“…The total energy in the four-pulse burst regime was as high as 46.7 mJ at a repetition rate of 25 kHz. A thin-disk laser with output power exceeding 10 kW of and high beam quality and consisting of two thin-disk laser oscillators and a thin-disk multi-pass amplifier system was presented in [28]. Those examples show the great potential of thin-disk lasers to scale up their power in a model-locked regime.…”

High-power modelocked thin-disk oscillators as potential technology for high-rate material processing

“…Commercially available industrial pumping modules with up to 72 pump-light passes allow us to efficiently pump the gain medium in this geometry despite the low single-pass absorption. In the same fashion, multiple passes can be used either in a resonator (oscillator or regenerative amplifier) or by geometric multiplexing or a combination of both to reach high gain per roundtrip and not being limited by the low gain per pass inherent to this geometry [ 14 ], [ 15 ], [ 16 ], [ 17 ], [ 18 ].…”

“…Alternatively, deformable mirrors can be used intracavity to compensate higher order aberrations [ 20 , 21 ]. In continuous-wave ( cw ) operation, powers well beyond 15 kW have been reached from a single-disk oscillator by the company TRUMPF [ 22 ], nearly single-fundamental operation ( M 2 = 1.76) was demonstrated at 10-kW average power using two polarization-combined oscillators and one multi-pass amplifier system [ 18 ] and a 4-kW fundamental mode oscillator with an M 2 of 1.4 was achieved [ 23 ]. All these results were achieved with Yb-doped garnets, emitting at 1030 nm wavelength, but there is continuous interest in the scientific community to explore other materials and dopant ions for extending these records to other wavelength regions as we will discuss in a following paragraph.…”

“…For even higher pulse repetition frequency in the MHz region, directly modelocked thin-disk oscillators, which will be described below, are a compelling alternative to more widely applied fiber-based systems in this power/pulse repetition frequency class, possibly also in combination with multipass booster thin-disk amplifiers in the future, for reaching the >10 kW average power regime. In fact, as discussed above, nearly-fundamental mode cw kW oscillators can be achieved in the thin-disk geometry [ 18 , 36 ]. Together with the small thickness and large areas on the disk, leading to low nonlinearities, this opens the door to kilowatt-class modelocked oscillators, which is in strong contrast to the fiber and slab geometries.…”

100 MW Thin-Disk Oscillator

“…efficiency, up to 30%, typically resulting in a few hundred watts of output power in the mode-locked regime [1][2][3] and a few thousand watts in the continuous-wave regime. [4] Particularly, the highest output peak powers demonstrated are 62 MW for a Kerr-lens mode-locked (KLM) oscillator [5] and 66 MW for a SESAM mode-locked oscillator. [6] A KLM oscillator with 102 MW peak power and 50 fs output pulse duration was recently demonstrated.…”