With the rapid emergence of artificial intelligence (AI) technology and the exponential growth in data generation, there is an increasing demand for high-performance and highly integratable optical ...modulators. In this work, we present an ultra-compact exciton-polariton Mach-Zehnder (MZ) modulator based on WS
multilayers. The guided exciton-polariton modes arise in an ultrathin WS
waveguide due to the strong excitonic resonance. By locally exciting excitons using a modulation laser in one arm of the MZ modulator, we induce changes in the effective refractive index of the polariton mode, resulting in modulation of transmitted intensity. Remarkably, we achieve a maximum modulation of -6.20 dB with an ultra-short modulation length of 2 μm. Our MZ modulator boasts an ultra-compact footprint area of ~30 μm² and a thin thickness of 18 nm. Our findings present new opportunities for the advancement of highly integrated and efficient photonic devices utilizing van der Waals materials.
Metalorganic chemical vapor deposition (MOCVD) has not been often used for studying exciton-polariton condensation and developing polaritonic devices, although it is a powerful mass productive method ...for practical applications. Here, we demonstrate that the MOCVD-grown GaAs-based microcavity can realize the nonequilibrium condensation of exciton-polariton. We obtained the Rabi splitting values of 10.1 meV in the angle-resolved reflectance spectrum from the MOCVD-grown microcavity. And, we also measured the angle-resolved photoluminescence depending on pumping power to observe condensation behaviors. Furthermore, we found that the occupancy distributions of polaritons are in a nonequilibrium state by fitting Bose-Einstein distributions. To realize the strong coupling and exciton-polariton condensation, we reduced the linewidth broadening of photoluminescence from quantum wells by optimizing growth conditions and designs.
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CMK, CTK, FMFMET, IJS, NUK, PNG, UL, UM, UPUK
Abstract Exciton polaritons are hybrid light‐matter quasi‐particles that hold exceptional opportunities for future optoelectronic devices. Taking the synergic advantages of room‐temperature ...perovskite excitons and topological photonic structures, topological exciton‐polaritons are experimentally demonstrated in organic–inorganic hybrid perovskite thin films. Topological junction structures based on perovskite gratings are realized using a momentum‐space analog of the 1D Dirac system. Desired enhancement phenomena are observed including narrow‐beam polariton emission from a tightly localized junction region, polaritonic nonlinearity boost, and enhanced luminescence. These remarkable features are obtained from highly compact devices with footprint widths on the order of a few micrometers and are efficiently tailorable with simple unit‐cell geometry control. Therefore, the proposed approach can be a powerful platform for room‐temperature topological exciton‐polaritons and concomitant device applications.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Monolithic germanium on silicon 1 dimensional photonic crystal cavity is presented. Numerical simulation shows Q ∼ 100,000 for the cavity mode overlapped with strained germanium nanostructure. Raman ...measurement shows up to 1.5 % of uniaxial tensile strain at the center of the cavity.
Monolithic germanium on silicon 1 dimensional photonic crystal cavity is presented. Numerical simulation shows Q ~ 100,000 for the cavity mode overlapped with strained germanium nanostructure. Raman ...measurement shows up to 1.5 % of uniaxial tensile strain at the center of the cavity.
Rotation of a container holding a viscous fluid forms a vortex which grows with increasing angular velocity. A superfluid, however, is intrinsically different from these normal fluids because its ...rotation is quantized. Even if a container of superfluid is rotating, the fluid itself remains still until a critical velocity is reached. Beyond the critical velocity, all the particles conspire to suddenly pick up an angular momentum of \(\hbar\) each and forms a quantized vortex. As a result, a superfluid is known to increase its rotation by a total angular momentum of \(N\hbar\). In this letter, we show that exciton-polariton superfluid can split into an irrotational part and a rotational part. The relative ratio between the two states can be controlled by either pump beam's power or spot size. Consequently, angular momentum of exciton-polariton superfluid can be tuned from zero to \(N\hbar\) continuously. This striking observation sets the stage for studying non-equilibrium properties of a superfluid with exciton-polaritons.
In this study, the heating characteristics of each part during driving
of the OLED panel were modeled. The main idea is to analyze how
power is consumed depending on the image in each part, and also
...analyze the temperature change over time, and compare the actual
measurement results and modeling results under various
conditions. This method can be used as a simulation tool that
predict heat generation according to the driving environment of
various product groups.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Background Vibration response imaging (VRI) is a new technique that captures lung sounds generated by the flow of air through the lungs. It predicts postoperative values for an intended lung ...resection. In this study, we measured the predicted postoperative pulmonary function as determined by a perfusion lung scan and the VRI, and compared with results from the postoperative pulmonary function. Methods This study was performed prospectively in patients who were candidates for major pulmonary resection. Each patient underwent a pulmonary function test, perfusion scintigraphy, and VRI within 1 week before operation. Postoperative lung function was measured at 4 to 6 weeks. Results The study enrolled 44 patients. There were no significant differences for predicted postoperative forced expiratory volume in 1 second (ppoFEV1 ) and predicted postoperative diffusion capacity of the lung for carbon monoxide (ppoD lco ) between scan and VRI. Both ppoFEV1 and ppoD lco using a scan and VRI predicted the postoperative results well, respectively. The postoperative FEV1 was correlated with ppoFEV1 using a scan ( r = 0.83, p < 0.001), and the ppoFEV1 using a VRI ( r = 0.83, p < 0.001). The postoperative D lco was correlated with the ppoD lco using a scan ( r = 0.85, p < 0.001), and the ppoD lco using a VRI ( r = 0.80, p < 0.001). Conclusions The VRI was highly predictive of postoperative FEV1 and D lco for lung resection.
