ACS Photonics最新文献

AlGaInP-based red micro-light-emitting diodes (micro-LEDs) act as promising candidates for red emitters of ultra-high-resolution displays. However, as the size of micro-LEDs decreases, the impact of sidewall defects on the efficiency degradation becomes more pronounced. The reduction in the number of quantum wells (QWs) can alleviate the sidewall effect and increase the external quantum efficiency (EQE) of AlGaInP-based flip-chip red micro-LEDs at a low current density. At 300 K, the maximum EQE of micro-LEDs with 3 pairs of QWs is 1.45 times those with 5 pairs, and a considerable enhancement in sidewall emission has been witnessed according to hyperspectral microscopic imaging. These improvements originate from reduced carrier loss in the sidewall region and enhanced radiative recombination in micro-LEDs with 3 pairs of QWs.

The advent of immune checkpoint blockade revolutionizes the landscape of cancer treatment. However, there are currently no biomarkers that can accurately predict the response of immunotherapy. In this work, we demonstrate label-free prediction of immunotherapy response in lung cancer using artificial intelligence-equipped multidimensional optical time-stretch imaging flow cytometry. First, the hypothesis of identifying immune activation of leukocytes via label-free images is confirmed using the in vitro coculture model. Then, with the support of the deep information mining capabilities of convolutional neural networks, we achieve prediction accuracies of 87 and 80% in lung cancer patients for the response and nonresponse to immunotherapy, respectively, significantly outperforming prediction using peripheral blood biomarkers. Furthermore, the experimental results on lung adenocarcinoma and lung squamous cell carcinoma patients show that our method is capable of predicting immunotherapy response with high accuracy across various types of lung cancer. We believe that our method can be applied to other types of cancer and will effectively enhance the specificity and efficacy of immunotherapy, thereby benefiting a large number of patients.

Erbium-doped thin-film lithium niobate (Er:TFLN) provides efficient solutions for monolithic integrated waveguide amplifiers and lasers, as well as the potential for electro-optic modulation and nonlinear application. However, the gain and saturation absorption characteristics usually lack dynamic analysis, which is highly valuable for various gain devices. We provide a practical framework for correlating the erbium absorption and signal wavelength/power in the erbium-doped waveguide amplifier (EDWA) on the Er:TFLN platform, demonstrating the gain performance of single-wavelength or multiwavelength signal amplification. The 10 cm long Er:TFLN EDWA achieves 62.76 dB signal enhancement at 1531 nm, with 22.26 dB internal net gain at the small signal region. Additionally, a significant on-chip output power of 16.65 dBm with 7.65 dB internal net gain is realized at 1550 nm. Furthermore, theoretical models and experimental results have been conducted on signal saturation power, output power, and noise figure. In multiwavelength signal amplification experiments, approximately 20 dB internal net gain and a noise figure of 4.36 dB are achieved for an electro-optic frequency comb with a 10 GHz repetition rate. Moreover, an internal net gain exceeding 20 dB is achieved across 45% of C-band broadband signals, establishing a solid foundation for relay amplification applications in high-capacity and multichannel data transmission systems. The gain dynamics proposed in this work can be effectively applied to design optimal EDWAs and lasers to construct monolithic integrated lithium niobate systems.

Skyrmionic hopfions are three-dimensional quasiparticles discovered in liquid crystals and magnetic materials. Analogous optical hopfions have been studied theoretically and experimentally demonstrated; however, their experimental mapping in a material has been challenging due to their complicated, three-dimensional polarization textures. In this work, we demonstrate the direct projection of the polarization textures of optical hopfions on azopolymers to form surface relief structures via optical radiation pressure. This demonstration offers new insights into the interaction between topologically protected quasiparticles of light and matter.

Disorder is often considered the opposite of order, lacking quantitative methods and being difficult to control. Disordered nanostructures can be conveniently prepared by bottom-up approaches, such as self-assembly, but their intrinsic randomness is often considered to lead to unpredictable results, impeding reproducibility and application. Here, we demonstrate that deterministic, angle-dependent visual appearances induced by specific correlated disorder can be achieved through bottom-up approaches, and reveal plenty of room for tailoring color appearance between order and random disorder. Two unprecedented iridescent visual appearances, backscattering iridescence (rainbow-like color transition covering more than five distinct colors at backscattering angles), and specular iridescent halo (gradual color changes in the visible light range around specular reflection direction), are proposed and demonstrated to be induced by correlated disorder at different degrees, which is regulated by interparticle distance. Besides elucidating the mechanism of iridescence generation, a comprehensive protocol for predicting the color appearance is established, and agrees well with experimental results. Combining bottom-up process, materials with low absorption, and tailored spatial disorder, we have endowed solar cells with colorful appearances, while maintaining the performance, which can serve as a solution for photovoltaic-integrated architectures and vehicles. This study advances the understanding of how disorder shapes color and angular appearance, and will find applications in energy photonics, dazzling arts, and anticounterfeiting.

Mid- and long-wave infrared photodetection is highly desired for various modern optoelectronic devices, but Si-based broadband photodetectors operating at room temperature remain challenging and are being extensively sought. In this paper, a Si-based photodetector with a broadband and fast photoresponse based on the photothermoelectric (PTE) effect of lead telluride (PbTe) film is demonstrated. Large-area, high-crystallinity PbTe film grown by a low-temperature, CMOS-compatible RF magnetron sputtering method is first reported for photodetection. The PbTe PTE photodetector surpasses the energy band gap limitation, operating even at wavelengths exceeding 10 μm. A rapid response time of less than 1 ms is obtained at 1310 nm, which is superior to those of most other reported PTE detectors. Furthermore, the development of a 5 × 5 array device shows a good photoresponse uniformity and demonstrates consistent mid-infrared imaging capabilities at room temperature. Excellent mechanical flexibility enables the integration of wearable optoelectronic devices. This pioneering research paves the way for significant advancements in Si-based broadband photodetector technologies, with potential applications in monolithic integrated detection and imaging systems that operate in visible- to long-wave infrared wavelengths at room temperature.