Anti-GST tag antibody [DyLight® 650]

Metasurfaces for chromatic aberration compensation have attracted a lot of research attentions since almost all imaging systems suffer from the intrinsic dispersion of composite materials and the chromatic aberration. However, most of them rely on complicated optimization of the structural parameters, hindering their practical application. Here we proposed a new and simple scheme of metasurface for chromatic aberration compensation based on phase change materials. As a demonstration, Ge2Sb2Te5(GST) is used to design metalens and deflector with reduced chromatic aberration that works over a broad band of wavelengths. Simulation results show that we can simply reduce the chromatic aberration from lambda = 8 mu m to lambda = 9 mu m via uniformly tuning the crystalline fraction of GST. In addition, we demonstrate that the working wavelength can be extended to a wider range from lambda = 8 mu m to lambda = 11 mu m via individually engineering the crystalline fraction of each GST cylinder. Our met-adevice serves as a novel paradigm for mid-infrared devices with compensated chromatic aberration, enabling a wide variety of application.

The influence of N concentration on the crystallization kinetics, microstructural evolution, and composition of Ge-rich GeSbTe (GGST) alloys during thermal annealing, using X-ray diffraction and scanning and transmission electron microscopy is reported. It is shown that the incorporation of N in GGST tends to slow down the phase separation, crystallization, and growth processes during annealing. This can be attributed to the reduced diffusivity of Ge, which interacts and quickly bonds with N. Technological advantages of N doping are also discussed, considering the increased stability of the amorphous phase with respect to its parent crystalline phase, finer microstructure, flatness of the GeSbTe (GST) films after crystallization, and disappearance of the low-resistivity hexagonal phase at high temperature.