Picometer-stable hexagonal optical bench to verify LISA phase extraction linearity and precision

TL;DR

This paper presents a highly stable hexagonal optical bench designed to verify the linearity and precision of phase extraction in LISA's metrology system, crucial for gravitational wave detection.

Contribution

It introduces a picometer-stable optical bench implementing a three-signal test for LISA phase measurement verification, demonstrating its suitability for a metrology benchmark.

Findings

Achieved picometer-level stability in the optical bench

Validated the bench's use for LISA phase measurement benchmarking

Demonstrated the bench's potential as a core component for LISA metrology verification

Abstract

The Laser Interferometer Space Antenna (LISA) and its metrology chain have to fulfill stringent performance requirements to enable the space-based detection of gravitational waves. This implies the necessity of performance verification methods. In particular, the extraction of the interferometric phase, implemented by a phasemeter, needs to be probed for linearity and phase noise contributions. This Letter reports on a hexagonal quasimonolithic optical bench implementing a three-signal test for this purpose. Its characterization as sufficiently stable down to picometer levels is presented as well as its usage for a benchmark phasemeter performance measurement under LISA conditions. These results make it a candidate for the core of a LISA metrology verification facility.