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Laser driven flyer (LDF) can drive small particles to ultrahigh speed (several km/s) by feeding pulse laser light, and exhibits giant application prospect in both of the civilian and military regions, such as the ignition of missile and spacecraft and dynamic high-pressure loading. In this work, we demonstrate a high-performance LDF by using the perfect metamaterial absorber (PMA) to improve the energy utilization efficiency of light. The designed Ag nanopillar array in anodic aluminum oxide templates (APA-AAO) were skillfully fabricated in-situ on the flyer layer surface, which can greatly reduce the reflectivity from 93% of the pure Al foil flyers to about 5% of the APA-AAO enhanced flyers. Our systematically transient analysis reveals that this ultralow reflectivity, together with the well-formed metal structure on Al foil, greatly improve both of the electron temperature and sustaining time of plasma formed in the ablating layer, and further enhances the acceleration process at both of the initial detonation wave generation stage (0–10 ns) and the following thermal expansion stage (10–200 ns). The final speed of the flyer generated in the PMA-enhanced LDF approach to 1730 m/s, which is about 1.4 times larger than that (1250 m/s) of the pure Al foil flyers. The transient electron temperature, transient flyer shadowgraph, plasma sustaining time, velocity, and accelerated velocity have been investigated systematically in this work. This PMA enhanced LDF provides an effective method for obtaining high-speed microparticles, and opens up a new perspective and guidance for designing high-performance LDF.

Three kinds of Al flyer plates with different nanostructured absorption layers were in situ prepared by a direct laser writing technology to improve the energy conversion efficiency in a laser-driven flyer assembly. Microstructures, light absorption, and flyer velocity in the acceleration chamber were investigated. The reflectance for the flyers at 1064-nm wavelength can be reduced from 81.3 to 9.8% by the nanostructured absorption layer. The terminal velocity of a 50-μm-thick Al flyer irradiated by a 60-mJ laser pulse is 831 m/s, while the velocity of the flyer with an in situ-fabricated nano-absorption layer reaches up to 1113 m/s at the same condition. Resultantly, the energy conversion efficiency of the flyer with a nanostructure absorption layer can reach as high as 1.99 times that of the Al flyer. Therefore, the nanostructured absorption layer in situ prepared on the surface of a flyer provides a new method to significantly improve the energy conversion efficiency of a laser-driven flyer.

In this study, energetic Al/Ni superlattice was deposited by magnetron sputtering. A micro-plasma generator was fabricated using the energetic Al/Ni superlattice. The cross-sectional micro-structure of the energetic Al/Ni superlattice was scanned by transmission electron microscopy. Results show that the superlattice is composed of Al layer and Ni layers, and its periodic structure is clearly visible. Moreover, the bilayer thickness is about 25 nm, which consists of about 15 nm Al layer and 10 nm Ni layer. The micro initiator was stimulated using a 0.22 μF capacitor charged at 2900–4100 V. The electrical behaviors were investigated by testing the current-voltage waveform, and the plasma generation was explored by ultra-high-speed camera and photodiode. The integrated micro generator exhibited remarkable electrical exploding phenomenon, leading to plasma generations at a small timescale. The plasma outputs reflected by flyer velocities were superior to that with a much thicker bilayer of 500 nm Al/Ni multilayer. The higher flyer velocity combined with Gurney energy model confirmed the chemical reaction of the Al/Ni superlattice structure contributed to plasma production in comparison with the Al/Ni multilayers. Overall, the energetic Al/Ni superlattice was expected to pave a promising avenue to improve the initiator efficiency at a lower energy investment.

In this work, we demonstrate a kind of new standing wave modes of carrying space beat-frequency effect in an optimized nanopillar array, which can greatly reshape the electric filed distribution and result in high-quality biosensors. The in-depth theoretical research reveals that the mismatch of SPP wave vector and the light wave vector of high-order modes in medium is the crucial factors. The coupling distance, the SPP propagation distance, and the structure parameters also have been systematically investigated. Our results enrich the standing wave modes in nanostructures and give new insights into the fundamental understanding of the standing wave modes.

The dramatic temperature rise of energetic materials when using only millisecond pulses of light is very important for photothermic ignition. Here we demonstrate a free-standing laser energy converter based on energetic graphene oxide, which exhibited an ultrafast and large temperature rise from 21 to 670 °C within 8.7 ms during the irradiation of laser pulses, while the temperature of the graphene-based laser energy converter can only be raised from 21 to 170 °C under the same conditions. The reason for the unexpected and much larger temperature rise of energetic graphene oxide than graphene was studied by laser scanning microscopy and thermal analysis, which indicated that the temperature rise is strongly dependent on the content of oxygen-containing groups in energetic graphene oxide. The combination process of focused ion beam and transmission electron microscope characterization was utilized for the direct observation of the layer-stacked structure in free-standing graphene oxide and graphene membranes. Furthermore, the initiating energy of laser initiators was 40% decreased by adding a thin layer of the free-standing laser energy converter based on energetic graphene oxide, which shows great potential for developing photothermic ignition with low initiating energy.

As a safe, reliable, and strongly electromagnetic resistant initiation method, laser initiation shows great promise in military blasting applications. Many obstacles exist when delivering a high-energy laser through optical fibers, directly influencing the energetic explosives under low-initiation conditions. Herein, we developed silver nanoplates as a laser energy absorber to reduce the laser initiation threshold and delay time. During the growth process of the silver seed nanoplates, mechanical disturbance was applied to provoke the nanoplates to develop more internal hotspots. Meanwhile, in ultraviolet visible near-infrared (UV–VIS-NIR) testing, the absorption peak was regulated to 808 nm by tailoring the size of the nanoplates. Results showed that the maximum temperature of the cracking nanoplates could reach 100 °C within 10 s, under the irradiation of an 808 nm diode laser at a power density of 1 W·cm−2. Through their use as a laser energy absorber, the silver nanoplates can effectively reduce the initiation threshold of cyclotrimethy lenetrinitramine (RDX) by 58.33% and reduce the delay time of B/KNO3 by 51.00%. This result provides potential applications for initiation energetic explosives at low laser energy.

MgAl hydride films with different hydrogen contents were fabricated in Ar and H2 mixed atmosphere using magnetron sputtering. Neutron reflectometry was performed to measure hydrogen contents, which indicated that up to 11atom% hydrogen was absorbed into MgAl. The MgAl hydride films were irradiated using pulsed lasers and the electron temperature and density of the generated plasma was measured. Results showed the electron temperature and density at delay time of 1μs were 7330 K, 7.9 × 1015 cm−3 and 8044 K, 9.0 × 1015 cm−3 for MgAl hydride films with 5atom% and 11atom% hydrogen, respectively. For comparison, the electron temperature and density for pure MgAl film were 5634 K and 6.9 × 1015 cm−3. Obviously, the electron temperature and density increases with the hydrogen content. Subsequently, the conversion ratio of the shock wave energy to the incident pulse energy were analyzed by investigating plasma induced shock wave evolution. The conversion ratio for MgAl hydride films with 5atom% and 11atom% hydrogen was 19.2% and 28.6%, which was 1.2 and 1.8 times of that for the MgAl film. Therefore, the MgAl hydride film promised to be a new class of material capable of promoting the plasma generation of the laser-driven flyers.

Light-ignited combustions have been proposed for a variety of industrial and scientific applications. They suffer, however, from ultrahigh light ignition thresholds and poor self-propagating combustion of typical high-energy density materials, e.g., 2,4,6,8,10,12-(hexanitrohexaaza)cyclododecane (CL-20). Here, reported is that both light ignition and combustion performance of CL-20 are greatly enhanced by embedding e-CL-20 particles in a graphene oxide (GO) matrix. The GO matrix yields a drastic temperature rise that is sufficient to trigger the combustion of GO/CL-20 under low laser irradiation (35.6 mJ) with only 6 wt% of GO. The domino-like reduction-combustion of the GO matrix can serve as a relay and deliver the decomposition-combustion of CL-20 to its neighbor sites, forming a relay-domino-like reaction. In particular, a synergistic reaction between GO and CL-20 occurrs, facilitating more energy release of the GO/CL-20 composite. The novel relay-domino-like reaction coupled with the synergistic reaction of CL-20 and GO results in a deflagration of the material, which generates a high-temperature pulse (HTP) that can be guided to produce advanced functional materials. As a proof of concept, a bi-layered photothermal membrane is prepared by HTP treatment in an extremely simple and fast way, which can serve as a model architecture for efficient interfacial water evaporation.