Multi-kW IR and green nanosecond thin-disk lasers

Abstract

Thin-disk lasers with multi-kW output power in continuous-wave operation are widely used for industrial materials processing due to their excellent beam quality, high efficiency, and high reliability with low investment and operation costs. We present our latest laboratory results of nanosecond thin-disk lasers with multi-kW average output power. We show that in pulsed laser systems almost the same average power and beam quality as in CW systems can be realized. Utilizing the cavity-dumping principle for pulse generation we demonstrated more than 4 kW of average output power with pulse energies exceeding 180 mJ. The laser generates pulses with a pulse duration of 20 ns which is almost independent of the power level and the repetition rate. The beam parameter product was measured to be better than 4.5 mm•mrad (M² < 14). Deploying intracavity frequency conversion the efficient generation of pulsed laser output in the green spectral range is investigated. Results for a q-switched thin-disk laser with an average power exceeding 1.8 kW and pulse durations between 100 ns and 300 ns are presented. First results for the external second and third harmonic generation of a nanosecond thin-disk laser using the cavitydumping principle are presented. With an incident IR average power of 2.3 kW more than 800 W at 515 nm are demonstrated for the second harmonic generation and more than 500 W at 343 nm are shown for the third harmonic generation with a pulse duration measured to be < 20 ns.