Fixed interdigital transducers (IDTs) are commonly limited to only generate a single type of surface acoustic wave (SAW). Here, we present a programmable IDT array architecture for multidimensional SAW generation, based on standard and chirped IDT array designs. Forty independently addressable IDT units are each modulated by a double-pole-double-throw switch to enable binary phase inversion. This system generates diverse SAW waveforms including non-diffracting Airy SAWs and dynamically focused SAWs. We achieve two-dimensional focus manipulation with sub-wavelength precision and extended focal depth, enabled by time-division multiplexing with chirped IDTs. By combining spatial phase encoding with spectral frequency multiplexing, our approach demonstrates multidimensional control over SAW generation, providing a platform for adaptive acoustic field control in applications such as reconfigurable microfluidics, tuneable metamaterials, and multifrequency sensing systems.

OBJECTIVE E26 transformation-specific (ETS) factors have emerged as key mediators underlying human tumorigenesis. Here, we sought to characterize the expression pattern, biological roles, and clinical significance of ETS Variant Transcription Factor 5 (ETV5) in head neck squamous cell carcinoma (HNSCC). SUBJECTS AND METHODS ETV5 expression pattern in HNSCC was determined by bioinformatics interrogations and immunohistochemical staining in primary samples. The associations between its abundance with clinicopathological parameters, and patient survival were evaluated. Colony formation, CCK-8, flow cytometry, wound healing, and Transwell invasion assays, as well as xenograft models, were utilized to determine the phenotypic changes after ETV5 silencing in vitro and vivo. The potential binding of ETV5 in the Slug promoter was determined by ChIP-qPCR. RESULTS ETV5 was significantly overexpressed in HNSCC samples. Its overexpression is significantly associated with aggressiveness features and reduced survival. ETV5 knockdown significantly inhibited cell proliferation, migration, invasion, and induced apoptosis in vitro, and impaired tumor growth in vivo. Moreover, ETV5-activated Slug transcription by binding its promoter region in HNSCC cells. Patients with ETV5high Slughigh had the worst survival across multiple HNSCC cohorts. CONCLUSIONS Our findings reveal that ETV5 serves as a novel prognostic biomarker and putative oncogene for HNSCC progression likely by activating Slug transcription.

We propose an innovative design for interdigital transducers (IDTs), enabling phase modulation of surface acoustic waves (SAWs) with a dislocated electrode structure. By designing the size and arrangement of these dislocated IDTs, a novel type of Airy SAWs can be generated, exhibiting self-accelerating, self-bending, and self-healing characteristics. The acceleration of the generated Airy SAW is 0.081 cm-1. Furthermore, particles and bubbles can be precisely manipulated using the generated Airy SAW. The proposed dislocated IDTs could be used for generation of many other types of SAWs, hence holding great promise for applications including SAW shaping, particle manipulation/sorting, and acoustic sensing/detection. Airy SAWs are generated with specially designed dislocated interdigital transducers (IDTs), exhibiting self-accelerating, self-bending, and self-healing characteristics.

Precisely controlling the optical characteristics of the microlens array (MLA) is a key issue for the MLA's fabrication and its applications. A cost-effective method for fabricating MLA with different curvatures and diameters by surface functionalization and electrohydrodynamic inkjet (E-jet) printing is proposed. The surface with self-assembled monolayers has low surface energy, which greatly improves the contact angle of the microlens. The UV-ozone treatment and neutral density filters with different optical densities are used to control the wettability of the substrates. Based on this method, the curvatures of the microlens can be controlled easily and the numerical aperture (NA) of the microlens can be adjusted from 0.18 to 0.49. Compared with traditional fabrication techniques, the method we demonstrated is flexible, low-cost, rapid, and capable of fabricating MLA with large area, high packing density, desirable NA, and diameters.

Compared to mechanical ones, liquid crystal (LC) beam deflectors present several advantages, such as non-mechanical control, compactness, and low power consumption, making them a viable alternative. In this work, we demonstrate an LC-based polarization-dependent, electrically tunable beam deflector, which is a composite blazed grating fabricated using a single-step photopolymerization-induced phase separation (PIPS) technique. We investigated the effect of different factors on the performance of the deflector, including the thickness of the upper substrate, the grating period, and the cell gap. The prepared sample demonstrated a diffraction angle of 2 degrees 6', and a diffraction efficiency of 40.0%. Unlike previous ones, our proposed fabrication technique for the LC beam deflector provides many benefits, such as simplicity, cost-effectiveness, and large-area production. (c) 2024 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement

Stimuli-responsive materials have garnered substantial interest in recent years, particularly liquid crystal networks (LCNs) with sophisticatedly designed structures and morphing capabilities. Extensive efforts have been devoted to LCN structural designs spanning from two-dimensional (2D) to three-dimensional (3D) configurations and their intricate morphing behaviors through designed alignment. However, achieving microscale structures and large-area preparation necessitates the development of novel techniques capable of facilely fabricating LCN microstructures with precise control over both overall shape and alignment, enabling a 3D-to-3D shape change. Herein, a simple and cost-effective in-cell soft lithography (ICSL) technique is proposed to create LCN microstructures with customized shapes and predesigned morphing. The ICSL technique involves two sequential steps: fabricating the desired microstructure as the template by using the photopolymerization-induced phase separation (PIPS) method and reproducing the LCN microstructures through templating. Meanwhile, surface anchoring is employed to design and achieve molecular alignment, accommodating different deformation modes. With the proposed ICSL technique, cylindrical and spherical microlens arrays (CMLAs and SMLAs) have been successfully fabricated with stimulus-driven polarization-dependent focusing effects. This technique offers distinct advantages including high customizability, large-area production, and cost-effectiveness, which pave a new avenue for extensive applications in different fields, exemplified by adaptive soft micro-optics and photonics.

Diffractive optical element is advantageous for miniaturization, arraying and integration of optical systems. They have been widely used in beam shaping, diffractive imaging, generating beam arrays, spectral optimization and other aspects. Currently, the vast majority of diffractive optics are not tunable. This limits the applicability and functionality of these devices. Here we report a tunable diffractive optical element controlled by light in the visible band. The diffractive optical element consists of a square gold microarray deposited on a deformable substrate. The substrate is made of a liquid crystal elastomer. When pumped by a 532 nm laser, the substrate is deformed to change the crystal lattice. This changes the far-field diffraction pattern of the device. The proposed concept establishes a light-controlled soft platform with great potential for tunable/reconfigurable photonic devices, such as filters, couplers, holograms and structural color displays.

Microlenses or arrays are key elements in many applications.However, their construction methods involve multiple fabrication processes, thereby increasing the complexity and cost of fabrication.In this study, we demonstrate an optically anisotropic, electrically tunable liquid crystal (LC) microlens array using a simple, one-step fabrication method.The microlens array is formed via photopolymerization-induced phase separation inside a polymer/LC composite.It possesses both polarization-dependent and electrically tunable focusing and imaging properties.Without applying voltage, the microlens array has a natural focal length of 8 mm, which is a result of its inherent gradient refractive index profile.Upon applying voltage above the threshold, the LC molecules reorient along the electric field direction and the focal length of the microlens array gradually increases.Based on its superior properties, the microlens array is further used for integral imaging applications, demonstrating electrically tunable central depth plane.Such LC microlens arrays could find numerous potential applications owing to their advantageous features of being flat, ultra-thin, and tunable, including 3D displays, optical interconnects, and more.

We demonstrated a low-cost, highly sensitive hybrid Ag-Cu substrate with enhanced absorption for the excitation laser beam via the nanosphere lithography technique. The hybrid Ag-Cu surface-enhanced Raman spectroscopy (SERS) substrate consists of a Cu nanoarray covered with Ag nanoparticles. The geometry of the deposited Cu nanoarray is precisely determined through a self-assembly nanosphere etching process, resulting in optimized absorption for the excitation laser beam. Further Raman enhancement is achieved by incorporating plasmonic hotspots formed by dense Ag nanoparticles, grown by immersing the prepared Cu nanoarray in a silver nitrate solution. The structural design enables analytical enhancement factor of hybrid Ag-Cu SERS substrates of 1.13 × 105. The Ag-Cu SERS substrates exhibit a highly sensitive and reproducible SERS activity, with a low detection limit of 10−13 M for Rhodamine 6G detection and 10−9 M for 4,4′-Bipyridine. Our strategy could pave an effective and promising approach for SERS-based rapid detection in biosensors, environmental monitoring and food safety.

In this work, we propose an acoustically tunable plasmonic device based on liquid crystal (LC)-covered gold nanostructures. By utilizing the standing surface acoustic waves (SSAWs) to realign LC molecules, one can effectively tune the effective refractive index of LCs, and subsequently tune localized surface plasmon resonances (LSPRs) of the gold nanostructures. A 15 nm blue shift of the LSPR peak with the driving voltage of 400 mV pp is experimentally observed. Upon removal of the applied SSAWs, the LC molecules can return to their original orientation, and so does the LSPR peak. Besides the excellent reversibility, this active plasmonic device also features low power consumption and easy integration, which could find many potential applications including switches, modulators, and couplers.

Microlenses or arrays are key elements in many applications. However, their construction methods involve multiple fabrication processes, thereby increasing the complexity and cost of fabrication. In this study, we demonstrate an optically anisotropic, electrically tunable liquid crystal (LC) microlens array using a simple, one-step fabrication method. The microlens array is formed via photopolymerization-induced phase separation inside a polymer/LC composite. It possesses both polarization-dependent and electrically tunable focusing and imaging properties. Without applying voltage, the microlens array has a natural focal length of 8 mm, which is a result of its inherent gradient refractive index profile. Upon applying voltage above the threshold, the LC molecules reorient along the electric field direction and the focal length of the microlens array gradually increases. Based on its superior properties, the microlens array is further used for integral imaging applications, demonstrating electrically tunable central depth plane. Such LC microlens arrays could find numerous potential applications owing to their advantageous features of being flat, ultra-thin, and tunable, including 3D displays, optical interconnects, and more.

Conventionally, the fabrication of liquid crystal lenticular microlens arrays (LCLMLAs) is complicated and costly. Here, we demonstrate a one-step fabrication technique for LCLMLAs, which is prepared through the photopolymerization-induced phase separation in the LC/polymer composite. The LCLMLAs possess both polarization-dependent and electrically tunable focusing properties. Furthermore, we construct a 14-view 2D/3D switchable autostereoscopic display prototype based on a 2D LCD panel and the prepared LCLMLA, which has a viewing angle of 14° and a crosstalk of 46.2% at the optimal viewing zone. The proposed LCLMLAs have the merits of simple fabrication, large-scale production, and low cost.

Surface-enhanced Raman spectroscopy (SERS) has long been an ultrasensitive technique for trace molecule detection. However, the development of a sensitive, stable, and reproducible SERS substrate is still a challenge for practical applications. Here, we demonstrate a cost-effective, centimeter-sized, and highly reproducible SERS substrate using the nanosphere lithography technique. It consists of a hexagonally packed Ag metasurface on a SiO2/Au/Si substrate. A seconds-lasting etching process of a self-assembled nanosphere mask manipulates the geometry of the deposited Ag metasurface on the SiO2/Au/Si substrate, which attains the wavelength matching between the optical absorbance of the Ag/SiO2/Au/Si substrate and the excitation laser wavelength as well as the enhancement of Raman signals. By spin-coating a thin layer of graphene oxide on the substrate, a SERS performance with 1.1 × 105 analytical enhancement factor and a limit of detection of 10−9 M for melamine is achieved. Experimental results reveal that our proposed strategy could provide a promising platform for SERS-based rapid trace detection in food safety control and environmental monitoring.

本文以"聚合物分散液晶光电器件设计与制备"实验为例阐述了将经典光学实验与前沿内容结合在教学中的运用.通过本文的实验设计可使学生了解聚合物分散液晶材料,掌握基于激光曝光技术制备包括智能窗、全息光栅、叉形光栅的方法和过程,重点引入涡旋光这一前沿光学研究课题,掌握利用叉形光栅产生涡旋光的原理与过程,并学习利用光学基础中的马赫曾德尔干涉仪检测涡旋光拓扑核的方法.通过实验,使学生意识到科学前沿并非空中楼阁,而是与基础理论密切相关.进而激发学生学习探索的热情,加强其基础知识储备,培养其创新型思维,为将来进一步的科研及工作打好基础.