Experimental investigation of a control scheme for a zero-detuning resonant sideband extraction interferometer for next-generation gravitational-wave detectors

TL;DR

This paper presents the development and successful experimental testing of a control scheme for a zero-detuning resonant sideband extraction interferometer, crucial for next-generation gravitational-wave detectors like LCGT.

Contribution

The paper introduces a novel control scheme for a PRZD RSE interferometer and demonstrates its successful locking in a prototype setup, advancing detector technology.

Findings

Successfully locked the PRZD RSE interferometer with the new control scheme

First experimental demonstration with suspended test masses

Supports future operation of LCGT gravitational-wave detector

Abstract

Some next-generation gravitational-wave detectors, such as the American Advanced LIGO project and the Japanese LCGT project, plan to use power recycled resonant sideband extraction (RSE) interferometers for their interferometer's optical configuration. A power recycled zero-detuning (PRZD) RSE interferometer, which is the default design for LCGT, has five main length degrees of freedom that need to be controlled in order to operate a gravitational-wave detector. This task is expected to be very challenging because of the complexity of optical configuration. A new control scheme for a PRZD RSE interferometer has been developed and tested with a prototype interferometer. The PRZD RSE interferometer was successfully locked with the control scheme. It is the first experimental demonstration of a PRZD RSE interferometer with suspended test masses. The result serves as an important step for the operation of LCGT.