High-power non-perturbative laser delivery diagnostics at the final focus of 100-TW-class laser pulses

Abstract

Controlling the delivery of multi-terawatt and petawatt laser pulses to final focus, both in position and angle, is critical to many laser applications such as optical guiding, laser–plasma acceleration, and laser-produced secondary radiation. We present an online, non-destructive laser diagnostic, capable of measuring the transverse position and pointing angle at focus. The diagnostic is based on a unique double-surface-coated wedged-mirror design for the final steering optic in the laser line, producing a witness beam highly correlated with the main beam. By propagating low-power kilohertz pulses to focus, we observed spectra of focus position and pointing angle fluctuations dominated by frequencies below 70 Hz. The setup was also used to characterize the excellent position and pointing angle correlation of the 1 Hz high-power laser pulses to this low-power kilohertz pulse train, opening a promising path to fast non-perturbative feedback concepts even on few-hertz-class high-power laser systems.

Control systems and data management for high-power laser facilities

“…It has been utilized primarily for research on the high-energy physics application of LPAs [ 6 ] , and more recently for ion acceleration studies and applications [ 69 ] . There are two 60 TW systems operating at up to 5 Hz, one of which couples a sophisticated electron beamline including an undulator to its LPA [ 70 ] , and another with two beamlines designed for MeV photon production via Thomson scattering [ 71 ] . Finally, the BELLA kHz LPA facility consists of a few-mJ few-cycle laser system operating at the kHz repetition rate, which can produce few-MeV electrons that are of interest in a variety of applications, including medicine and security.…”

Wavefront Correction in Vacuum of SULF-1PW Laser Beamline

“…Wavefront aberrations are the main limitation to the realization of ideal focal spots and it can be divided into two categories: static aberration, resulting from the aberration of optical elements; and dynamic aberration, mostly originating from the thermal loading in the laser system [11]. The adaptive optical system (AOS) based on a deformable mirror (DM) is generally applied in high peak power lasers, in order to correct the wavefront aberration and therefore improve the focusing quality [12][13][14][15][16]. Sometimes, double AOSs with cascaded correction functions are also used, in view of the large beam size and serious aberration [17][18][19][20].…”