Displacement-noise-free resonant speed meter for gravitational-wave detection

TL;DR

This paper introduces a resonant Sagnac interferometer-based speedmeter that effectively eliminates mirror displacement noise, enhancing low-frequency gravitational-wave detection sensitivity compared to previous designs.

Contribution

It presents a novel displacement-noise-free resonant speedmeter using a double pumped Sagnac interferometer, improving low-frequency GW detection capabilities.

Findings

Displacement noise of cavity mirrors can be fully excluded.

Displacement-noise-free response is stronger at low frequencies.

The design outperforms previous displacement noise free interferometers.

Abstract

We demonstrate that speedmeter, based on double pumped resonant Sagnac interferometer, can be used as a displacement noise free gravitational-wave (GW) detector. The displacement noise of cavity mirrors can be completely excluded through a proper linear combination of the output signals. We show that in low-frequency region the obtained displacement-noise-free response signal is stronger than the one in previously proposed displacement noise free interferometers.