High-energy laser pulses at 1064 nm with complex temporal shapes

Abstract

Laser pulses are a powerful tool for inducing a large diversity of dynamical phenomena in matter. Control over the temporal shape of light pulses therefore also provides a means to control such dynamics on a wide range of timescales. Our aim is to improve control over laser-produced plasmas (LPP) and its short-wavelength emission characteristics, where plasma dynamics at nanosecond (ns) timescales play an important role. To investigate and control such dynamics, we need to combine GHz bandwidth pulse shaping capabilities with high pulse energies. The development of fast, compact, integrated electro-optic modulators (EOM) has made arbitrary temporal shaping at GHz speed accessible [1, 2]. However, the penalty for their fast modulation speed is a low power threshold, usually in the mW regime. Therefore, to enable fast temporal shaping of high-energy laser pulses, amplification after shaping is necessary. Here we present a laser system capable of delivering arbitrary shaped pulses with 0.5 ns temporal resolution and up to 440 mJ of pulse energy at 1064 nm wavelength and 100 Hz repetition rate. A grazing incidence amplifier utilizing Nd:YVO 4 crystals pumped at 880 nm [3] is seeded by a modulated 2W CW laser. Further amplification is obtained by utilizing a quasi-CW diode-pumped Nd:YAG power amplifier. A schematic of the full setup is shown in Figure 1a.