Frequency noise and intensity noise of next-generation gravitational-wave detectors with RF/DC readout schemes

TL;DR

This paper analyzes how RF/DC readout schemes in next-generation gravitational-wave detectors influence frequency and intensity noise, especially in the resonant-sideband-extraction configuration, considering radiation pressure effects.

Contribution

It extends previous laser noise analysis to include the resonant-sideband-extraction configuration with radiation pressure effects and DC readout schemes.

Findings

Frequency noise can be amplified in the resonant-sideband-extraction configuration.

Intensity noise impact varies with readout scheme and optical configuration.

Radiation pressure effects significantly influence laser noise behavior.

Abstract

The sensitivity of next-generation gravitational-wave detectors such as Advanced LIGO and LCGT should be limited mostly by quantum noise with an expected technical progress to reduce seismic noise and thermal noise. Those detectors will employ the optical configuration of resonant-sideband-extraction that can be realized with a signal-recycling mirror added to the Fabry-Perot Michelson interferometer. While this configuration can reduce quantum noise of the detector, it can possibly increase laser frequency noise and intensity noise. The analysis of laser noise in the interferometer with the conventional configuration has been done in several papers, and we shall extend the analysis to the resonant-sideband-extraction configuration with the radiation pressure effect included. We shall also refer to laser noise in the case we employ the so-called DC readout scheme.