Nonclassical Interferometry towards Gravitational-Wave Detectors at a Laser Wavelength of 2.1um

2.1um 激光波长下引力波探测器的非经典干涉测量

基本信息

批准号：
388405737
负责人：
Professor Dr. Roman Schnabel, since 8/2019
金额：
--
依托单位：
Institut für Laser-Physik
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2017
资助国家：
德国
起止时间：
2016-12-31 至 2021-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/388405737?language=en
关键词：
Nonclassical Interferometry towards Gravitational Wave

项目摘要

The recent direct observation of gravitational waves from a binary black-hole merger has marked the beginning of gravitational-wave astronomy. To enable a continuous stream of detections with a high signal-to-noise ratio, upcoming generations of gravitational-wave detectors, which are based on the principle of laser interferometry, will aim at an increase of strain sensitivity by at least an order of magnitude. Through most of the detection band, the limiting noise sources are given by thermal noise in the mirror coatings and substrates, as well as quantum noise of the laser light field. Future detectors foresee a change to crystalline silicon as mirror material and operation at cryogenic temperatures. This will need to be accompanied by a change in laser wavelength to around 2µm, from the currently used 1µm. At the same time, squeezed states of light have been successfully shown to reduce the quantum noise in gravitational-wave detectors. Combining these two advancements is therefore a major step towards a successful era of gravitational-wave astronomy. So far, laser development at around 2µm has been driven by LIDAR and medical applications, therefore little experience exists with the demanding stability requirements for high-power lasers in gravitational-wave detectors. Furthermore, squeezed light has not been demonstrated at 2µm, and photo detectors with a near-unity quantum efficiency - so as to not destroy the fragile nonclassical correlations in the squeezed field - are not yet available.The project team will develop a complete solution for 2µm laser technology aimed at gravitational-wave detection that is solely based on degenerate parametric down-conversion of the existing highly stable 1064nm laser sources. Within this project, we will develop a squeezed-light source at 2.128µm, demonstrating for the first time that this wavelength is compatible with advanced quantum-noise reduction techniques. In addition, we will show compensation of detection loss by optical parametric amplification, partly removing the need for photo detectors with almost perfect quantum efficiency. The results of this work will thus play a significant role in planning and enabling future gravitational-wave detectors, pushing the boundaries of the observable universe.

最近对双黑洞合并引力波的直接观测标志着引力波天文学的开始，为了实现高信噪比的连续探测，即将推出的新一代引力波探测器。基于激光干涉测量原理，旨在将应变灵敏度提高至少一个数量级。在大部分检测频带中，限制噪声源由反射镜涂层和基底中的热噪声给出，以及激光光场的量子噪声。未来的探测器预计将采用晶体硅作为反射镜材料并在低温下运行，这需要将激光波长从目前使用的 1μm 更改为 2μm 左右。与此同时，光的压缩态已被成功地证明可以减少引力波探测器中的量子噪声，因此，将这两项进步结合起来是迈向引力波天文学成功时代的重要一步。激光雷达和医疗应用推动了 2μm 左右激光的发展，因此在引力波探测器中高功率激光器的严格稳定性要求方面缺乏经验。此外，2μm 的压缩光和具有 2μm 波长的光电探测器尚未得到证实。近乎统一的量子效率——以免破坏压缩场中脆弱的非经典相关性——尚不可用。项目团队将为针对引力波的2μm激光技术开发完整的解决方案检测完全基于现有高度稳定的 1064nm 激光源的简并参数下转换，在该项目中，我们将开发 2.128μm 的压缩光源，首次证明该波长与先进的量子兼容。此外，我们将展示通过光学参量放大补偿检测损失，部分消除对具有几乎完美量子效率的光电探测器的需求。因此，这项工作的结果将在规划和研究中发挥重要作用。使未来的引力波探测器成为可能，突破可观测宇宙的界限。