Optical cavities with both optimized resonant conditions and high quality factors are important metrological tools. In particular, they are used for laser gravitational wave (GW) detectors. It is necessary to suppress the parametric instability by damping the resonant conditions of harmful higher order optical modes (HOOM) in order to have high cavity powers in GW detectors. This can be achieved effectively by using non spherical mirrors in symmetric Fabry-Perot (FP) cavities by increasing roundtrip losses of HOOMs. Fabry-Perot cavities in most of the GW detectors have non-identical mirrors to optimize clipping losses and reduce thermal noise by reducing the beam size on one side of the cavity facing to the beam splitter and recycling cavities. We here present a general method to design non spherical non-identical mirrors in non-symmetric FP cavities to damp HOOMs. The proposed design allows to the suppress the loss of the arm power caused by point absorbers on test masses.

中文翻译：

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具有不同非球面镜的法布里-珀罗腔的衍射损耗

具有优化谐振条件和高质量因子的光腔是重要的计量工具。特别是，它们用于激光引力波 (GW) 探测器。为了在 GW 探测器中具有高腔功率，有必要通过抑制有害高阶光学模式 (HOOM) 的谐振条件来抑制参数不稳定性。这可以通过在对称法布里-珀罗 (FP) 腔中使用非球面镜通过增加 HOOM 的往返损耗来有效实现。大多数 GW 探测器中的法布里-珀罗腔具有不同的反射镜，以通过减小面向分束器和回收腔的腔一侧的光束尺寸来优化削波损耗并降低热噪声。我们在这里提出了一种在非对称 FP 腔中设计非球面非相同反射镜以抑制 HOOM 的通用方法。建议的设计允许抑制由测试质量上的点吸收器引起的臂功率损失。