In the past few decades, subwavelength antireflection structures have attracted significant attention due to their wide range of applications, such as the photovoltaic industry, optical devices, and flexible displays. With the aid of advanced nanofabrication techniques, subwavelength antireflection structures exhibit high-performance antireflective properties, high-quality mechanical and environmental stability, excellent temperature stability, and high laser damage resistance. This paper first introduces the basic concept of subwavelength antireflection structures and then elaborates on the theoretical research progress in this field. Furthermore, a systematic summary and compilation of the preparation methods for this unique structure are provided, along with examples of fabricating subwavelength antireflection structures on transparent substrates. Additionally, the practical applications and potential value of subwavelength antireflection structures on transparent substrates in areas such as solar cells, light-emitting diodes and organic light-emitting diodes, agricultural greenhouses, and transportation display components are discussed briefly. Finally, the formidable challenges and future development trends faced by subwavelength antireflection structures are presented.

Temporal-divided dual-pulses-amplification (TDDPA) has proven to be a valuable tool to enhance the energy extraction efficiency (EEE) and extend the functions of kilojoules-scale picosecond petawatt (PW) laser facility. Without any observed degradation of the original chirped pulse amplification, TDDPA profit an additional nanosecond shaped pulse (NSP) laser with thousands of joules of energy and the capability of independent adjustment of output energy, pulse shape, and temporal delay. In this letter, we demonstrate TDDPA based on the multi-passes main amplifier system (MAS) of the prototype beam of SGII-Upgrade laser facility. Besides the 2580J/1.9ns/3.8nm chirped pulse, an additional NSP with 2898J/2ns/0.1nm/140ns delay are obtained simultaneously in one shot, which can act as an independent NSP beam after separation.

Conventional thin film materials do not meet the requirements for tunable optical performance, and one solution is the preparation of nano-composite coatings using ion-beam co-sputtering deposition. This study investigates the variations in properties such as refractive index, transmission spectra, optical bandgap, crystal structure, and nonlinear absorption (NLA) of (TiO2:Ta2O5) composite coatings with different TiO2 doping levels and annealing temperatures. The results indicate that with an increase in TiO2 doping levels, the refractive index of the nano-composite coatings significantly increases, while the optical bandgap monotonically decreases. Nonlinear absorption characteristics of the composite films were measured using aperture z-scan techniques for femtosecond (64 fs), high repetition rate (1 kHz), and near-infrared (NIR) (800 nm) pulsed lasers. The test curves confirm the existence of a reverse saturable absorption effect, and the obtained nonlinear absorption coefficient exhibits a strong correlation with the changes in the optical bandgap induced by doping in the composite coatings. Furthermore, the microstructural changes resulting from annealing the composite coatings at different temperatures also affect their nonlinear absorption. Summarizing the impact of TiO2 doping ratios and annealing temperatures on the nonlinear absorption properties of nano-composite coatings can contribute to the development of new materials for laser thin films.

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Laser plasma accelerators have seen an incredible development over the 2 past decades, leading to production of high electron energy close to 10 GeV as well as remarkable improvement of their stability and robustness using the most modern digital technologies such as machine learning. However, they use up to now low repetition rate lasers what restricts their use in many societal applications in industry and medicine where high accelerator currents are required for efficiency and speed of the process are required. This is why Thales and LOA have decided to develop a new electron acceleration platform within the LAPLACE HC project, using a brand new high repetition rate Ti:Sa laser system operating at a repetition rate of 100 Hz becoming therefore compatible with the requirements of most societal applications of electron acceleration. During this presentation we will introduce the latest results obtained from Titanium Sapphire amplifiers at 100 Hz with output energy close to 1 Joule and average power close to 100 Watts, the highest level ever obtained so far with Ti:Sa, thanks to a significant improvement in Ti:Sa crystals thermal management allowing to reduce the pump-induced thermal focusing within the crystals while operating at ambient temperature

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Electron–photon scattering is one of the most fundamental mechanisms in electrodynamics, underlying laboratory and astrophysical sources of high-energy X-rays. After a century of studies, it is only recently that sufficiently high electromagnetic field strengths have been available to experimentally study the nonlinear regime of the scattering in the laboratory. This can act as a new generation of accelerator-based hard X/γ-ray sources driven exclusively by laser light. One ultrahigh intense CPA laser pulses will act as two means: first used to accelerate electrons by laser driven wake field (LWFA) to hundreds MeV, and second, from split beam or LWFA-leftover energy reflected by plasma mirror, to collide on the electron for the generation of X/γ-rays. Such all-laser-driven X/γ source have recently been demonstrated to be energetic, tunable, narrow/broad in bandwidth, short pulsed and well collimated. Such characteristics, especially from a compact source, are highly advantageous for numerous advanced X-ray applications. Moreover, the scattering interaction can act a test bed for high-field QED study. Also, preliminary plan of laser wake-field accelerator and radiation source in two high-power laser facilities, 0.5PW in SJTU and 2.5PW in TDLI will be presented, both lasers include two independently compressed two beamlines.

High power fiber lasers have drawn enormous attention in scientific and industrial communities due to high efficiency, good beam quality, robust structure and low cost. With the rapid development of high brightness pump sources and high quality fiber materials, power scaling of fiber lasers is one of the most important issues in recent years. One of the most limiting factors is the onset of mode degradation at high power operation, which can be induced by various physical effects in fibers, such as stimulated thermal Rayleigh scattering, stimulated Raman scattering, stimulated Brillouin scattering, four wave mixing, photodarkening and so on. Here the mode degradation in high power fiber lasers has been reviewed with the most recent study and newest achievements.

Pulse contrast, as the intensity ratio between the main pulse and noise in the temporal domain, is an essential parameter of high-power laser, measuring the temporal quality of intense laser pulse. If the pre-contrast is poor, the noise in the leading edge of the main pulse will disturb the laser-plasma interaction. To ensure a pre-plasma free interaction, the pre-noise intensity should be controlled below the ionization threshold (~1011 W/cm2). It means that the pulse contrast should be as high as 1012 for current multi-PW-class lasers with a focused intensity up to 1023 W/cm2, and even higher for future 100-PW lasers. Precise characterization for pulse contrast with a sufficient dynamic range is vital to the pulse-contrast improvement in these high-power laser facilities. In this talk, we will report our effects toward single-shot characterization for pulse contrast with a dynamic range up to 1013. In addition, the method to support simultaneously large temporal window and high temporal resolution will be introduced too. Several prototype devices for single-shot pulse-contrast characterization have been developed for the PW-class lasers in China.

We propose a new way of transporting orbital angular momentum (OAM) and generating axial magnetic fields in a non-relativistic laser intensity regime by using a twisted light to stimulate the two-plasmon decay instability (TPD) in a plasma. The growth of TPD driven by an OAM light in a Laguerre-Gauss (LG) mode is investigated through both three-dimensional fluid simulations and theory. TPD is found intrinsically excited in a non-collimated way as the most unstable modes involve pairs of EPWs that propagate at fairly large angles with respect to the propagation direction of the pump laser. This non-collimated geometry of the dominant modes is another key feature that would make TPD grow in a very distinguished way from the collimated forward/backward SRS and SBS in the previous OAM Stimulated Raman/ Brillouin Scatter (SRS/SBS) studies. A theory based on the assumption that the electron plasma waves (EPWs) are locally driven by a number of local plane-wave lasers predicts the maximum growth rate proportional to the peak amplitude of the pump laser field, which is verified by the simulations. The OAM conservation during its transportation from the laser to the TPD daughter EPWs is shown by both the theory and the simulations. The theory predicts generation of ∼ 40T axial magnetic fields through the OAM absorption via TPD, which has perspective applications in the field of high energy density physics.