Direct observations of gravitational waves at frequencies below 10 Hz will play a crucial role in fully exploiting the potential of gravitational wave astronomy. One approach to pursue this direction is the utilization of laser interferometers equipped with Fabry–Pérot optical cavities in space. However, there are a number of practical challenges in following this path. In particular, the implementation of precision control for cavity lengths and the suppression of laser phase noises may prevent a practical detector design. To circumvent such difficulties, we propose a new interferometer topology, called a back-linked Fabry–Pérot interferometer, where precision length controls are not required and an offline subtraction scheme for laser phase noises is readily applicable. This article presents the principle idea and the associated sensitivity analyses. Despite additional noises, a strain sensitivity of $$7\times10^{-23}\,\textrm{Hz}^{-1/2}$$ may be attainable in the decihertz band. Several technological developments must occur and studies must be carried out to pave the way for the implementation.

中文翻译：

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用于星载引力波观测的反向法布里-珀罗干涉仪

对频率低于 10 Hz 的引力波的直接观测将在充分利用引力波天文学的潜力方面发挥关键作用。追求这个方向的一种方法是在太空中使用配备法布里-珀罗光学腔的激光干涉仪。然而，在这条道路上存在许多实际挑战。特别是，腔长的精确控制和激光相位噪声的抑制可能会妨碍实际的探测器设计。为了避免这些困难，我们提出了一种新的干涉仪拓扑，称为反向链接法布里-珀罗干涉仪，其中不需要精确的长度控制，并且激光相位噪声的离线减法方案很容易应用。本文介绍了原理思想和相关的敏感性分析。尽管有额外的噪声，但在分赫频带中可能会获得 $$7\times10^{-23}\,\textrm{Hz}^{-1/2}$$ 的应变灵敏度。必须发生一些技术发展，并且必须进行研究为实施铺平道路。