Department of Materials, Imperial College London, Exhibition Road, London SW7 2AZ, UK.
London Centre for Nanotechnology, Imperial College London, Exhibition Road, London SW7 2AZ, UK.
Nature. 2018 Mar 21;555(7697):493-496. doi: 10.1038/nature25970.
The maser-the microwave progenitor of the optical laser-has been confined to relative obscurity owing to its reliance on cryogenic refrigeration and high-vacuum systems. Despite this, it has found application in deep-space communications and radio astronomy owing to its unparalleled performance as a low-noise amplifier and oscillator. The recent demonstration of a room-temperature solid-state maser that utilizes polarized electron populations within the triplet states of photo-excited pentacene molecules in a p-terphenyl host paves the way for a new class of maser. However, p-terphenyl has poor thermal and mechanical properties, and the decay rates of the triplet sublevel of pentacene mean that only pulsed maser operation has been observed in this system. Alternative materials are therefore required to achieve continuous emission: inorganic materials that contain spin defects, such as diamond and silicon carbide, have been proposed. Here we report a continuous-wave room-temperature maser oscillator using optically pumped nitrogen-vacancy defect centres in diamond. This demonstration highlights the potential of room-temperature solid-state masers for use in a new generation of microwave devices that could find application in medicine, security, sensing and quantum technologies.
由于依赖于低温制冷和高真空系统，微波激射器——光学激光的微波前体——一直处于相对默默无闻的状态。尽管如此，由于其作为低噪声放大器和振荡器的无与伦比的性能，它还是在深空通信和射电天文学中找到了应用。最近，在 p-三联苯基质中利用光激发的五苯分子的三重态中的极化电子群体展示了一种室温固态微波激射器，为一类新的微波激射器铺平了道路。然而，p-三联苯的热学和力学性能较差，而且五苯分子的三重子亚层的衰减率意味着，在这个系统中只能观察到脉冲微波激射器的运转。因此，需要替代材料来实现连续发射：已经提出了包含自旋缺陷的无机材料，如金刚石和碳化硅。在这里，我们报告了一种使用金刚石中光学泵浦的氮空位缺陷中心的连续波室温微波激射振荡器。这一演示突出了室温固态微波激射器在新一代微波器件中的应用潜力，这些器件可能在医学、安全、传感和量子技术中找到应用。
