We have demonstrated high-peak-power generation at 1 kW average power by applying an acousto-optic Q switch to a quasi-cw diode-pumped Nd:YAG master oscillator power amplifier. We achieved a maximum peak power of 2.3 MW by driving the Q switch in burst mode. The average repetition rate was 6 kHz. The corresponding beam quality was M2 = 9.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1364/ao.44.004119 | DOI Listing |
Nanotechnology
January 2025
Electronic Sci.&Eng., Xi'an Jiaotong University, 28 Xianning West Road,Beilin District, Xi 'an, Shaanxi Province, China, Xi'an, 710049, CHINA.
The accurate estimation of the temperature distribution of the GaN based power devices and optimization of the device structure is of great significance to possibly solve the self-heating problem, which hinders the further enhancement of the device performances. We present here the operando temperature measurement with high spatial resolution using Raman spectroscopy of AlGaN/GaN high electron mobility transistors (HEMTs) with different device structures and explore the optimization of the device thermal design accordingly. The lateral and depth temperature distributions of the single-finger HEMT were characterized.
View Article and Find Full Text PDFJ Clin Gastroenterol
January 2025
Department of Gastroenterology and Hepatology, University Hospitals Leuven, Leuven, Belgium.
Background: Swallowed topical corticosteroids (STC) are an effective first-line therapy for patients with eosinophilic esophagitis (EoE), both for induction and maintenance of remission. All interventional trials with STC used twice-daily dosing regimens. However, in other inflammatory gastrointestinal disorders, corticosteroids are given once daily (OD) with equal outcomes and improved compliance.
View Article and Find Full Text PDFMater Horiz
January 2025
State Key Laboratory of Organic-Inorganic Composites, College of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing 100029, China.
Solar energy sources have garnered significant attention as a renewable energy option. Despite this, the practical power conversion efficiency (PCE) of widely used silicon-based solar cells remains low due to inefficient light utilization. In this study, carbon dots (APCDs) were prepared a hydrothermal method using ammonium polyphosphate and -phenylenediamine, then incorporated into a silicone-acrylic emulsion (CAS) to create a luminescent down-shifting (LDS) layer for solar cells.
View Article and Find Full Text PDFWave mixing (WM) techniques are crucial for applications such as supercontinuum generation, frequency conversion, and high-dimensional quantum encoding. However, their efficiency is often limited by complex phase-matching requirements, and current insights into phase-matching mechanisms for high-order WM remain limited. To address this, compact optical path configurations with high-peak-power, synchronous, multicolor ultrafast laser sources are needed to enhance high-order wave-mixing efficiency.
View Article and Find Full Text PDFWe present a wideband rectifying metasurface (RMS) with enhanced system efficiency for wireless power transmission and energy harvesting. The RMS consists of periodic arrays with integrated diodes, with a high input impedance matched with the diodes, thus eliminating the matching network between metasurface (MS) and rectifier. Besides, a unique harmonic feedback network is embedded in each unit cell, rectifying the high-order harmonic generated by the diode repeatedly, improving the total efficiency over a wide bandwidth.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!