Terahertz phononic crystal in plasmonic nanocavity

Interaction between photons and phonons in cavity optomechanical systems provides a new toolbox for quantum information technologies.A GaAs/AlAs pillar multi-optical mode microcavity optomechanical structure can obtain phonons with ultra-high frequency(~THz).However,the optical field cannot be effectively restricted when the diameter of the GaAs/AlAs pillar microcavity decreases below the diffraction limit of light.Here,we design a system that combines Ag nanocav-ity with GaAs/AlAs phononic superlattices,where phonons with the frequency of 4.2 THz can be confined in a pillar with~4 nm diameter.The Q_(c)/V reaches 0.22 nm^(-3),which is~80 times that of the photonic crystal(PhC)nanobeam and~100 times that of the hybrid point-defect PhC bowtie plasmonic nanocavity,where Q_(c) is optical quality factor and V is mode volume.The optome-chanical single-photon coupling strength can reach 12 MHz,which is an order of magnitude larger than that of the PhC nanobeam.In addition,the mechanical zero-point fluctuation amplitude is 85 fm and the efficient mass is 0.27 zg,which is much smaller than the PhC nanobeam.The phononic superlattice-Ag nanocavity optomechanical devices hold great potential for applications in the field of integrated quantum optomechanics,quantum information,and terahertz-light transducer.

Exosomes in malignant pleural effusions:Sources and applications

To the Editor:Malignant pleural effusion(MPE)is a collection of a large amount of exudativeuid in the pleural cavity that mainly originates from pleural metastases in patients with malignant tumors.The formation of MPE is related to angiogenesis,increased vascular permeability,lymphatic obstruction,immune reactions,and the tumor metastasis microenvironment,but molecular-based diagnostic and next-generation therapeutic strategies for MPE are still lacking.Exosomes are vesicles with a double-layered lipid membrane structure that are widely distributed in bodyuids and can be produced by almost all cells.Increased evidence has shown that exosomes are related to the development of MPE and are correlated with the efcacy of and response to targeted therapy or immunotherapy.Although exosomes are one of the main components of MPE,the source and functional role of exosomes in MPE are still unclear.

Mahalanobis-Taguchi system: a systematic review from theory to application

The Mahalanobis-Taguchi system(MTS)is a relatively new multi-dimensional pattern recogni-tion technology that combines Mahalanobis distance(MD)with Taguchi’s robust engineering for diagnosis and prognosis.MTS operation process generally consists of four specialised stages,namely,Mahalanobis space(MS)construction,MS validation,MS optimisation,and diagnosis and prognosis.In recent years,a significant amount of research work has been conducted on the improvement of key technologies and these four processes.Numerous applications of MTS have also been studied in various fields.There are,of course,excellent reviews of theoretical research and applied research of MTS.However,there is no systematic review that covers both theoretical and applied research comprehensively.To fill this gap,this paper reviews MTS from key technolo-gies,four processes and application research,and provides researchers with a discussion of the current situation,upcoming challenges and possible future trends.

Design of unidirectional emission silicon/llI-V laser for on-chip interconnects

We propose a unidirectional emission silicon/ III-V laser, which comprises an III-V quantum wells microdisk connected to an output waveguide and a siliconon-insulator （SOI） waveguide. Characteristics of the III-V microdisk with an output waveguide and mode coupling between the III-V output waveguide and the SO1 waveguide are investigated by three-dimensional （3D） finite-difference time-domain （FDTD） method. Simulation results show that the Q factor of a coupled mode for a 7.5 μm diameter microdisk connected to a 0.5 μm wide output waveguide is about 8.5×10^4. And the coupling efficiency between the III-V output waveguide and the SO1 waveguide is over 96% when the III-V waveguide width is 0.5 μm, the SO1 waveguide width is 0.565 μm and the vertical gap between those two waveguides is 0.1μm. The proposed hybrid laser would be of valuable applications for on-chip interconnects.