脉动中子星的参量不稳定性诱导标量引力波

第三代引力波探测器参量振荡不稳定性的抑制

Suppression of parametric oscillatory instability in third generation gravitational wave detectors

讨论了通过确定干涉仪反射镜的最佳曲率半径来抑制下一代引力波探测器法布里-珀罗腔中参量振荡不稳定性的非线性效应的一种可能方法。通过改变反射镜的曲率半径，我们可以改变法布里-珀罗谐振腔的光学模式的频率和光学模式中的光场分布，这反过来又可以改变不稳定模式的数量，从而导致参数振荡不稳定性。确定了利用热透镜减少不稳定模数目的最佳反射镜曲率半径。

长光腔中的参量不稳定性及动态横模频率调制的抑制

Parametric Instability in Long Optical Cavities and Suppression by Dynamic Transverse Mode Frequency Modulation

在先进的引力波探测器中，预言了三模参量不稳定性。在这里，我们提出了第一次观察到这种现象，在一个大规模的悬浮光学腔设计的先进的引力波探测器。我们的研究结果表明，以前的建模假设，横向光学模式是稳定的频率，除了热变形时间尺度上的频率漂移是不太可能是有效的悬浮质量光学腔。我们证明了镜形误差引起的光斑位置的横向模式偏移频率的依赖性。结合悬挂镜的低频剩余运动，这导致抑制有效参量增益的横模频率调制。我们表明，这种增益抑制机制可以通过激光光斑抖动或快速热调制来增强。使用先进的LIGO测试质量数据和热建模，我们表明，增益抑制因子为10-20可以实现的个别模式，足以大大改善参数不稳定性问题。

Stellar Instability from Parametric Resonance

In this paper we examine the stability of stellar configurations in which the interior solution is described by a closed FLRW geometry sourced with a charged pressureless fluid and radiation. An interacting vacuum component and a conformally coupled massive scalar field are also included. Given a simple factor for the energy transfer between the pressureless fluid and the vacuum component we obtain bounded interior oscillatory solutions. We show that in proper domains of the parameter space the interior dynamics is highly unstable so that the break of the KAM tori leads to a disruptive ejectio…

Mitigation of Parametric Instability

A key action for enhancing the sensitivity of gravitational wave (GW) detectors based on laser interferometry is to increase the laser power. However, in such a high-power regime, a nonlinear optomechanical phenomenon called parametric instability (PI) leads to the amplification of the mirrors vibrational modes preventing the detector functioning. Thus this phenomenon limits the detectors maximum power and so its performances. Our group has started an experimental research program aiming at realizing a exible and active mitigation system, based on the radiation pressure applied by an auxiliary…

大尺度引力波干涉仪参量不稳定性的时间演化

Time evolution of parametric instability in large-scale gravitational-wave interferometers

本文研究了大尺度引力波探测器中的三模参量不稳定性。以前的工作使用线性化模型来研究不稳定的发生。本文对这种现象进行了非线性研究，结果表明，在反射镜的高阶光学模和机械内模的振幅指数上升的初始阶段之后是一个饱和阶段，在此阶段中，所有三个参与模式都达到一个新的平衡态，其振荡振幅保持不变。结果表明，在存在这种不稳定性的情况下，干涉仪的稳定操作是可能的，从而简化了抑制的任务。

High speed, high power 2D beam steering for mitigation of optomechanical parametric instability in gravitational wave detectors

In this paper we propose a novel strategy to control optomechanical parametric instability (PI) in gravitational wave (GW) detectors, based on radiation pressure. The fast deflection of a high power beam is the key element of our approach. We built a 2D deflection system based on a pair of acousto-optic modulators (AOMs) that combines high rapidity and large scan range. As fast frequency switching configurable AOM driver we used an Universal Software Radio Peripheral (USRP) combined with a high performance personal computer (PC). In this way we demonstrate a 2D beam steering system with flat e…

先进LIGO中参量不稳定性光学反馈控制的首次演示

First Demonstration of Optical Feedback Control to Parametric Instability at Advanced LIGO

本文首次在公里级引力波探测器中演示光学反馈控制，成功抑制了10.428 kHz的不稳定模式，将参量增益从R=2降至R<0.02，验证了该方案对实现兆瓦级循环功率的有效性。