Abstract

Erbium-doped glasses represent a foundational material platform for optical amplification in telecommunications, primarily enabling efficient signal gain within the low-loss C-band (1530–1565 nm) and L-band (1565–1610 nm) silica fiber transmission windows. When incorporated into erbium-doped fiber amplifiers (EDFAs), these glasses use the Er³⁺ ions (⁴I_13/2 to ⁴I_15/2) transition to enhance optical signals with the least amount of noise degradation. By enabling all-optical amplification of wavelength-division multiplexed (WDM) signals without the need for expensive optical-electrical-optical conversion, their integration transformed long-haul optical communications and served as the foundation for contemporary underwater and terrestrial cable networks. To improve gain bandwidth, flatness, and noise performance, recent research has focused on optimizing glass host compositions, including silicates, phosphates, borates, and ternary systems. Pump absorption and power scalability are further enhanced by co-doping techniques (such as Er/Yb), and sophisticated designs tackle issues like excited-state absorption (ESA) in prolonged L-band operation (>1610 nm). To increase bandwidth, efficiency, and integration capabilities for next-generation networks, future advancements will keep improving amplifier architectures and glass chemistry. The goal of the current assessment is to highlight the importance of the most recent developments in the telecommunications device industry based on EDFAs.

Abstract

Micro and nano sensors lie at the core of critical innovations spanning from medical and environmental sciences to industrial applications and security systems. In recent years, significant advancements have been made in sensor design for temperature, radiation, and volatile organic compound (VOC) detection, driven by progress in micro- and nano-fabrication technologies and the use of newly engineered functional materials. Advanced micro- and nano-fabrication techniques enable the production of these sensors at micro- and nanoscale dimensions, facilitating their integration into sensor arrays while maintaining high sensing performance and allowing miniaturization. These developments have particularly enhanced the sensitivity and selectivity of integrated platforms for precise measurement of radiation levels, selective detection of VOCs in ambient air, and accurate monitoring of temperature variations. Previously, various micro- and nanoscale sensors have been proposed and studied for these three categories, each exhibiting distinct advantages and limitations in terms of detection sensitivity, power consumption, response time, and recovery time. This study provides a comprehensive review of recent progress in micro- and nano-fabrication technologies for temperature, radiation, and VOC sensors. The functional materials employed, advanced microfabrication methods, and their impact on sensor design are discussed. Furthermore, the working principles, structural configurations, and performance characteristics of these sensors are examined. Finally, potential application areas and future technological developments for each sensor type are outlined.

Abstract

Clean graphene offers strong potential for a wide range of energy applications, including storage, conversion, harvesting, and catalysis. Ongoing efforts to preserve its purity are essential for advancing sustainable and efficient technologies. Although chemical vapor deposition can produce large, high-quality graphene sheets, scaling the method for industrial use remains challenging. Issues with film uniformity and reproducibility often arise, particularly in quartz furnace systems, where unintended particle deposition can affect growth dynamics and material properties. This study investigates how these contaminants develop and traces their origins. It also proposes practical modifications to quartz furnace designs to minimize impurities and achieve more consistent large-area films. Detailed analysis using SEM, XPS, and Raman spectroscopy provides clear insight into the structural and chemical features of both as grown and transferred graphene.

Abstract

In this report, we introduce the research progress of biochemical sensing technology based on terahertz (THz) metasurface sensors. Terahertz metasurfaces have achieved significant progress and practical applications in the research of THz functional materials and devices. Currently, the sensing and detection applications based on THz metasurfaces have also become an important and frontier research topic in THz sensing technology. Aiming at the application requirements of biochemical substance’s sensing and detection, based on the design, preparation, characterization, and mechanism analysis of THz metasurfaces with ordering of functional units, we have developed THz metasurface sensing chips with high quality factors (Q-factor). Additionally, we have explored methods to improve the high-sensitive sensing and detection of biochemical molecules using THz metasurface sensors, providing references for the development of high-sensitive THz sensing technology.