High-intensity vortex beams with tunable topological charges and low coherence are highly demanded in applications such as inertial confinement fusion (ICF) and optical communication. However, t

High-intensity vortex beams with tunable topological charges and low coherence are highly demanded in applications such as inertial confinement fusion (ICF) and optical communication. However, traditional optical vortices featured with non-uniform intensity distributions are dramatically restricted in application scenarios that require a high-intensity vortex beam owing to their ineffective amplification resulting from the intensity-dependent nonlinear effect. Here, a low-coherence perfect vortex beam (PVB) with a topological charge as high as 140 is realized based on the super-pixel wavefront-shaping technique. More importantly, a globally adaptive feedback algorithm (GAFA) is proposed to efficiently suppress the original intensity fluctuation and achieve the flat-top PVB with dramatically reduced beam speckle contrast. The GAFA based flat-top PVB generation method can pave the way for high-intensity vortex beam generation which is crucial for potential applications in ICF, laser processing, optical communication, and optical trapping.show less

This paper presents the development and experimental utilization of a synchronized off-harmonic laser system designed as a probe for ultra-intense laser-plasma interaction experiments. The syste

This paper presents the development and experimental utilization of a synchronized off-harmonic laser system designed as a probe for ultra-intense laser-plasma interaction experiments. The system exhibits a novel seed-generation design, allowing for a variable pulse duration spanning over more than three orders of magnitude, from 3.45 picoseconds to 10 nanoseconds. This makes it suitable for various plasma diagnostics and visualization techniques. In a side-view configuration, the laser was employed for interferometry and streaked shadowgraphy of a laser-induced plasma while successfully suppressing the self-emission background of the laser-plasma interaction, resulting in a signal-to-self-emission ratio of 110 for this setup. These properties enable the probe to yield valuable insights into the plasma dynamics and interactions at PHELIX and to be be deployed at various laser facilities due to its easy-to-implement design.show less

Mid-spatial frequency wavefront deformation can be deleterious for the operation of high-energy laser systems. When fluid cooled high-repetition rate amplifiers are used, the coolant flow is lik

Mid-spatial frequency wavefront deformation can be deleterious for the operation of high-energy laser systems. When fluid cooled high-repetition rate amplifiers are used, the coolant flow is likely to induce such detrimental mid-spatial frequency wavefront deformations. Here, we describe the design and performance of a 90×90 mm² aperture, liquid-cooled Nd:phosphate split-slab laser amplifier pumped by flash lamps. The performance of the system is evaluated in terms of wavefront aberration and gain at repetition rates down to 1 shot per minute. The results show that this single cooled split-slab system exhibits low wavefront distortions in the medium to large period range, compatible with a focus on target, and despite the use of liquid coolant traversed by both pump and amplified wavelengths. This makes it a potential candidate for applications in large high-energy laser facilities.show less

Fast neutron absorption spectroscopy is widely used in study of nuclear structure and element analysis. However, due to long pulse duration (of the order of nanosecond) of traditional pulsed fas

Fast neutron absorption spectroscopy is widely used in study of nuclear structure and element analysis. However, due to long pulse duration (of the order of nanosecond) of traditional pulsed fast neutron sources, it is difficult to realize a fine absorption spectrum. Here, we present a method of ultra-high energy-resolution absorption spectroscopy via a high repetition rate, pico-second duration fast neutron source driven by a Tera-Watt laser plasma electron accelerator. The technology of single neutron count is used, which results in easily distinguish the width of ∼20 keV at 2 MeV and the asymmetric shape of the neutron absorption peak. The absorption spectroscopy proposed has one order of magnitude higher energy-resolution power than the state-of-art traditional neutron sources, which could be benefit for deep understanding the theoretical model of neutron physics and more precisely measuring the nuclear structure data.show less