Metasurface technology is revolutionizing the field of optics and pursuing expanded functions via technical developments, such as the integration of multiple metasurfaces with optical fibers. Despite several attempts to realize metasurface-on-fiber platforms, negligible fiber-facet areas pose a serious obstacle to efficient and precise fabrication. Herein, we demonstrate a novel sequential micro-punching process that enables rapid and precise stacking of multiple polymer metasurfaces on the end face of a single-mode optical fiber. Mesh-type nanohole metasurfaces are fabricated on a 1.8-μm-thick polymethyl methacrylate (PMMA) layer via e-beam lithography, and the PMMA layer is separated from the substrate and prepared in the form of a membrane using the external frame. Furthermore, the PMMA metasurfaces are sequentially punched through the fiber and stacked on top. Employing a micro-punching process, we demonstrate highly efficient all-polymer metalenses and orbital angular momentum (OAM) metasurfaces coupled with single-mode fibers operating in the telecommunication band. A 1550 nm laser beam passing through three metalens layers stacked on the fiber is focused at a distance of 135 μm with 83% efficiency. In addition, the 1550 nm beam passing through three OAM metasurfaces on the fiber is converted into a perfect vortex beam with a topological charge of 3. We believe that our proposed micro-punching process will cause a breakthrough in the fabrication of metasurface-integrated optical fibers that will be utilized in a wide range of applications.

The purpose of this study is to investigate the reliability of static balance measurements using a smartphone.Thirty subjects were selected among university students who had no fractures, history of operation, or inflammatory arthritis, and they had not started regular exercise during the past three months. The smartphone used in this study was a Galaxy S5LTE (SM-G900F, Samsung, Korea, 2014), and the application was a Sensor Kinetics Pro (Ver. 2.1.2, INNOVENTIONS Inc., US, 2015). Static balance ability was measured three times at one-day intervals between tests and retests. The first and second measurements used the same process. Analysis was done using the Wilcoxon signed rank test and intraclass correlation coefficient (ICC (2,1)). The results were as follows. With eyes opened, there was no significant difference (p>0.05), a high volume of correlation (r>0.75, p<0.05), and very high reliability (ICC>0.80) between the first measurement and second measurement. With eyes closed, there was also no significant difference (p>0.05), a high volume of correlation (r>0.75, p<0.05), and very high reliability (ICC>0.80) between the measurements. The results show that the smartphone is likely accurate for measuring static balance. This study will look forward to being the only basis for measuring future application development and the ability to balance.

MXene, an ultra-thin two-dimensional conductive material, has attracted considerable interest in various fields due to its exceptional material properties. In particular, Ti3C2Tx MXene exhibits distinct optical properties, enabling it to support surface plasmons in the shortwave infrared (SWIR) region. However, it is challenging to enhance the field confinement of MXene surface plasmons in a single-interface structure due to the substantial intrinsic absorption of Ti3C2Tx MXene. Herein, we explore various multilayer structures capable of supporting high field confinement of Ti3C2Tx MXene plasmons, including insulator-MXene-insulator (IMI), MXene-insulator-MXene (MIM), and insulator-MXene-insulator-MXene (IMIM) configurations. We observe that the field confinement of MXene plasmons improves as the thickness of either the MXene or insulator layers decreases, which is attributed to the strong coupling between plasmons at the multilayer interfaces. Furthermore, the IMIM structure demonstrates the most substantial enhancement in field confinement. In an IMIM structure with a 1.3 nm-thick MXene monolayer and a 1.0 nm-thick SiO2 layer, the wavelength and effective field size of the plasmon at a frequency of 150 THz (λ0 = 2.0 μm) are calculated to be 24.61 nm and 1.50 nm, respectively. These values demonstrate a reduction by factors of 55 and 596, respectively, compared to those obtained in a single SiO2-MXene interface structure. Multilayer-based MXene plasmons provide a solution for enhancing the field confinement of MXene plasmons in the SWIR region, and we expect them to play a crucial role in a variety of 2D material-based SWIR plasmonic applications.&#xD;

We directly observed the ice recrystallization in real-time within a space of tens of nanometers using plasmonic nanoantennas. At the same time, we were able to elucidate the mechanism of inhibition of ice recrystallization.

Light localization with plasmons in 2D material is restricted to mid- or long-wave infrared. Here, we demonstrate plasmons in 2D MXene, covering whole mid-infrared range. MXene plasmon exhibits wavelength 20 times shorter than vacuum wavelength.