Status of the GEO 600 squeezed-light laser

TL;DR

This paper characterizes the squeezed-light laser used in GEO 600, reviews its integration status, identifies optical loss sources limiting squeezing, and discusses future improvements for enhanced measurement sensitivity.

Contribution

It provides a detailed characterization of the GEO 600 squeezed-light laser and analyzes current limitations and future prospects for reducing optical losses.

Findings

Identification of optical loss sources limiting squeezing

Current measurement sensitivity improvements achieved

Potential strategies for future loss reduction

Abstract

In the course of the high-frequency upgrade of GEO 600, its optical configuration was extended by a squeezed-light laser [1]. Recently, a non-classically enhanced measurement sensitivity of GEO 600 was reported [2]. In this paper, a characterization of the squeezed-light laser is presented. Thereupon, the status of the integration into GEO 600 is reviewed, focussing on the sources of optical loss limiting the shot noise reduction by squeezing at the moment. Finally, the possibilities for a future loss reduction are discussed.