Quantum Optoelectronics

Abstract:

Thyroid cancer remains prevalent worldwide, with its incidence steadily increasing in recent decades. Although ultrasonography is currently the primary screening method in clinical practice, its relatively low specificity has contributed to increased overdiagnosis. Furthermore, conventional ultrasonography is associated with challenges such as high inter- and intra-observer variability and limited functional imaging capabilities, which together reduce its diagnostic accuracy. To address these limitations, researchers have explored complementary image-based techniques to assess the vascularity surrounding cancerous nodules. This comprehensive review provides an overview of recent clinical trials investigating advanced ultrasound (US)-based imaging techniques for diagnosing thyroid cancer in humans. Specifically, we explore the use of photoacoustic imaging and ultrafast US Doppler techniques, highlighting their potential to enhance triaging accuracy by enabling the analysis of both structural and functional characteristics of thyroid nodules in vivo. Integrating these innovative approaches into existing ultrasonography protocols could significantly enhance the precision of thyroid cancer diagnosis.

Abstract:

Green ammonia evolution by photocatalytic means has gained significant attention over recent decades, however, the energy conversion efficiency remains unsatisfactory, and deep mechanistic insights are absent. Here in this work, this challenge is addressed by developing a photothermal system that synthesizes ammonia from nitrogen and natural seawater under simulated solar irradiation, employing ruthenium‐doped barium tantalum oxynitride semiconductors. This method significantly enhances solar‐to‐ammonia conversion efficiency, providing a viable alternative to the energy‐intensive Haber–Bosch process. Optimized at 240 °C, the system achieves an ammonia evolution rate of 5869 µmol g−1 h−1 in natural seawater. Moreover, detailed characterizations have shown that the use of seawater not only leverages an abundant natural resource but also improves the reaction kinetics and overall system stability. The catalysts maintain their activity and structural integrity over multiple cycles, demonstrating both the feasibility and the durability of this innovative system. Achieving a solar‐to‐ammonia efficiency of 13% and an overall energy conversion efficiency of 6.3%, this breakthrough highlights the potential to decentralize ammonia production, enhancing accessibility and sustainability. This approach combines the benefits of thermal and photocatalytic processes, marking a significant advancement in ammonia synthesis technology.

Abstract:

We have estimated the intrinsic complex refractive index spectrum of a CsPbBr3 nanocrystal. With various dilute solutions of CsPbBr3 nanocrystals dissolved in toluene, effective refractive indices were measured at two different wavelengths using Michelson interferometry. Given the effective absorption spectrum of the solution, a full spectrum of the effective refractive index was also obtained through the Kramers–Krönig relations. Based on the Maxwell–Garnett model in the effective medium approximation, the real and imaginary spectrum of the complex refractive index was estimated for the CsPbBr3 nanocrystal, and the dominant inaccuracy was attributed to the size inhomogeneity.

Abstract:

Data for paper on plasmonic enhanced emission from perovskite nanowires

Abstract:

Flexible optoelectronics have broad applications in healthcare and various industries. Unlike traditional (two-dimensional) 2D designs, flexible 3D optical sensors enable advanced functions like light directionality detection, intensity mapping, and velocity measurement. However, their integration with 2D circuit boards adds manufacturing complexity. Solving this could unlock untapped applications in navigation, agriculture, and remote sensing. In this study, selective buckling of flexible circuit boards is investigated to develop an all-in-one flexible (three-dimensional) 3D optical sensor for light detection with high sensitivity to periodic light pulses. By employing a buckling-based design, the developed flexible 3D phototransistor is found to be adjustable for measuring incident light angles between 0° and 87°, with an average error of less than 5°. Additionally, the sensor is able to measure object velocity with a maximum deviation of only 1.5% from the actual speed. In this design, the flexible circuit board is also integrated with Bluetooth Low Energy (BLE) technology to wirelessly transmit readings to a smartphone application to enable efficient data processing, transmission, visualization, and analysis. The platform's effectiveness is then demonstrated for unmanned aeraial vehicles (UAV) navigation and solar tracking, highlighting its strong potential for real-world use in autonomous systems and environmental monitoring.