No abstract

The development of infrared stealth clothing technology and materials has been widely studied. However, the research of near-infrared stealth clothing still faces some challenges including complex preparation processes, narrow spectral ranges, and poor antidetection efficiency. To solve these questions, a CoGaZnSe multilayer film used for anti-near-infrared detection is designed and prepared by pulse laser deposition (PLD) at different pressures from 2 to 12 Pa. Microstructures of the film can transform from amorphous to crystal at different Ar atmospheres demonstrated by X-ray diffraction, Raman spectroscopy, and theoretical calculations. The films with different transmittances from 10 to 95% are combined with multilayer films for reducing the infrared reflection, which results in the lowest energy loss per unit thickness of 1.01 × 10 −11 dB/cm. The light propagation in the multilayer is calculated by finite-difference time domain, revealing the regular sinusoidal propagation and absorption in multilayers. The multilayer films are coated on the surface of common clothing materials and tested using an infrared detector in the range of 400−6000 nm. The results prove that the quantum efficiency of infrared detection can be effectively reduced by CoGaZnSe multilayer films, especially for wool (83% in the range of 400−1800 nm and 86% in the range of 2000−6000 nm). Finally, a physical model is established to discover the mechanism of the antireflection and infrared effect and a theory of anti-infrared radiation. This research provides a new idea and method supporting the stealth technology and materials, which improves the efficiency of antiinfrared detection and makes it feasible to be applied in military, detection, and stealth technology.

As a new type of photonic‐chip light source, quantum dot (QD) lasers have recently received remarkable attention. However, two significant problems remain to be solved: the high lasing threshold characteristics and the single wavelength application in a photonic chip. To achieve this, a multi‐wavelength quantum dot laser is proposed. An ultrathin QDs‐film laser with a thickness of 78 nm is developed. The microstructure of MAPbBr3 + graphene + CoGaZnS is studied using Raman spectroscopy and simulation, illustrating the different optical bandgap structures in different combinations. Four‐wavelength lasing at 540, 628, 769, and 824 nm with thresholds of 25 kW cm–2 and 50 kW cm–2 are achieved at room temperature. The finite‐difference time‐domain (FDTD) simulation results suggest a photon‐jumping phenomenon in a fixed period. Subsequently, the transient absorption (TA) spectrum of the QDs‐film is measured to reveal the ultrafast photonics process, which proves the two hot‐carrier transfer processes and the zitterbewegung (ZB) phenomenon in graphene at 416 nm. The ZB‐dominated hot‐carrier transfer from perovskite MAPbBr3 to CoGaZnS is confirmed. This study can contribute to hot‐carrier lasing and light‐source research in photonic chips.