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Your search keyword '"Wen, Yongqiang"' showing total 611 results
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611 results on '"Wen, Yongqiang"'

1. Portable diamond maser with reduced magnetic field through orientation

Author

Ng, Wern, Wen, Yongqiang, Alford, Neil, and Arroo, Daan M.

Subjects
Quantum Physics, Condensed Matter - Materials Science, Physics - Applied Physics, Physics - Instrumentation and Detectors
Abstract

Masers have the potential to transform medical sensing and boost qubit readout detection due to their superb low-noise amplification. The negatively-charged nitrogen vacancy (NV-) diamond maser is the only continuous-wave solid-state maser discovered at room temperature, however it suffers from requiring large and bulky magnets which prevent its more widespread use. We present a significant reduction in size of the entire diamond maser using a much lighter and small-footprint electromagnet, reducing the weight from an immovable 2000 kilograms to a portable 30 kilograms. We achieve a maximum maser output power near -80 dBm, ten times higher than the first implementation, and have discovered techniques to reduce the magnetic field strength required for masing by precise manipulation of the spin orientation. With the diamond maser now shrunk to a size that can fit on a lab benchtop, we have brought continuous-wave room temperature masers away from the confines of research laboratories and closer to transforming readouts in quantum computing, frequency standards and quantum-limited medical sensing., Comment: 8 pages, 3 figures

Published
2024

2. `Maser-in-a-Shoebox': a portable plug-and-play maser device at room-temperature and zero magnetic-field

Author

Ng, Wern, Wen, Yongqiang, Attwood, Max, Jones, Daniel C, Oxborrow, Mark, Alford, Neil McN., and Arroo, Daan M.

Subjects
Quantum Physics, Condensed Matter - Materials Science, Physics - Applied Physics, Physics - Instrumentation and Detectors, Physics - Optics
Abstract

Masers, the microwave analogues of lasers, have seen a renaissance owing to the discovery of gain media that mase at room-temperature and zero-applied magnetic field. However, despite the ease with which the devices can be demonstrated under ambient conditions, achieving the ubiquity and portability which lasers enjoy has to date remained challenging. We present a maser device with a miniaturized maser cavity, gain material and laser pump source that fits within the size of a shoebox. The gain medium used is pentacene-doped in para-terphenyl and it is shown to give a strong masing signal with a peak power of -5 dBm even within a smaller form factor. The device is also shown to mase at different frequencies within a small range of 1.5 MHz away from the resonant frequency. The portability and simplicity of the device, which weighs under 5 kg, paves the way for demonstrators particularly in the areas of low-noise amplifiers, quantum sensors, cavity quantum electrodynamics and long-range communications.

Published
2023
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4. Exploring the Spin Dynamics of a Room-Temperature Diamond Maser using an Extended rate Equation Model

Author

Wen, Yongqiang, Diggle, Philip L., Alford, Neil McN., and Arroo, Daan M.

Subjects
Condensed Matter - Materials Science, Physics - Applied Physics, Physics - Instrumentation and Detectors
Abstract

Masers - the microwave analogue of lasers - are coherent microwave sources that can act as oscillators or quantum-limited amplifiers. Masers have historically required high vacuum and cryogenic temperatures to operate, but recently masers based on diamond have been demonstrated to operate at room temperature and pressure, opening a route to new applications as ultra-low noise microwave amplifiers. For these new applications to become feasible at a mass scale, it is important to optimise diamond masers by minimising their size and maximising their gain, as well as the maximum input power of signals that can be amplified. Here, we develop and numerically solve an extended rate equation model to present a detailed phenomenology of masing dynamics and determine the optimal properties required for the cavity, resonator and gain medium in order to develop portable maser devices. We conclude by suggesting how the material parameters of the diamond gain media and dielectric resonators used in diamond masers can be optimised and how rate equation models could be further developed to incorporate the effects of temperature and nitrogen concentration on spin lifetimes., Comment: 23 pages, 8 figures

Published
2023
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32. A Crack Detection Method for an Insulator Based on the Optical Frequency Domain Reflectometry Fiber Sensing System.

Author

Zhao, Jing, Wen, Yongqiang, Yu, Aodi, Li, Wei, and Xia, Li

Subjects
REFLECTOMETRY, SPATIAL resolution, BACKSCATTERING, OPTICAL time-domain reflectometry
Abstract

In this paper, a method for detection of crack locations and the width of basin insulators is proposed. Based on the optical frequency domain reflectometry (OFDR) system, the system utilizes an FBG with high feedback for strain as well as temperature, which is affixed to the surface of the tub insulator, and a common single-mode optical fiber, which is used for transmitting data and connected to the optical backscattering reflectometry interrogator. The interrogator measures the backscattered light from the FBG, which varies with temperature or strain. The method has been used to measure the location and width of several different cracks and can locate the crack position with a spatial resolution of 1 mm and measure the crack width with a resolution of 0.77 mm. The method has been used to measure the position and width of insulators. This method provides a simple and fast approach to crack detection in insulators. [ABSTRACT FROM AUTHOR]

Published
2024
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