Ultrafast thin-disk multi-pass amplifier system providing 1.9 kW of average output power and pulse energies in the 10 mJ range at 1 ps of pulse duration for glass-cleaving applications.

Thomas Dietz,Dirk Sutter,Michael Scharun,Michael Jenne,Alexander Killi,Dominik Bauer

doi:10.1364/oe.383926

Abstract

An ultrafast Yb-doped thin-disk multi-pass laser amplifier system with flexible parameters for material processing is reported. We can generate bursts consisting of four pulses at a distance of 20 ns and a total energy of 46.7 mJ at a repetition rate of 25 kHz. In single-pulse operation, 1.5 kW of average output is achieved at 400 kHz when optimizing for a beam quality of M2 = 1.5. Alignment for maximum output power provides 1.9 kW at the same repetition rate. All results are obtained without chirped-pulse amplification in the multi-pass set-up. The application potential of the system is demonstrated exploring its performance in materials processing of dielectrics. Cleaving of 3.8-mm-thick SCHOTT borofloat glass with a velocity of 1200 mm/s is demonstrated with 300 W of input power. Single-pass modification of 30 mm borosilicate glass is enabled with a Bessel beam at 1 kW of average power delivered by four-pulse bursts of an energy of 30 mJ.

Highlights

IntroductionMaterials processing with of ultrafast pulsed laser sources became a rapidly growing field of industry
During the last years, materials processing with of ultrafast pulsed laser sources became a rapidly growing field of industry
With a repetition rate of 25 kHz, an average output power of 1.2 kW is achieved. These values correspond to a burst energy of 46.7 mJ and a single-pulse energy as high as 11.7 mJ

Summary

Introduction

Materials processing with of ultrafast pulsed laser sources became a rapidly growing field of industry. Several applications like e.g. suface structuring [6,7] or cleaving of glass [8,9,10,11] demand even higher average powers and pulse energies. To achieve this goal, several concepts were demonstrated during recent years. By means of regenerative amplifiers, pulse energies up to 220 mJ were achieved at a repetition rate of 1 kHz [17,18]. There is no need for an intra-cavity optical switch, which tends to limit the pulse energy for CPA-free regenerative amplifiers [20]. Glass-cleaving applications exploiting this output performance are presented

High-power laser source

Findings

Conclusion and outlook