Lasers and squeezed light

The AEI has a long history in the design, fabrication and installation of lasers and squeezed light sources in ground based gravitational-wave interferometry.

Pre-stabilized high power lasers were developed for and installed at GEO600 and Advanced LIGO and squeezed-light sources developed and built at the AEI improve the sensitivity of GEO600 and Advanced Virgo. Currently the “Lasers and squeezed light” group at the AEI focuses its research and development on stabilized high power lasers and non-classical light sources for next generation gravitational-wave detectors, such as the Einstein Telescope and Cosmic Explorer.

Benno Willke and Henning Vahlbruch are co-chairs in the laser and squeezed-light work packages of the Einstein Telescope and contribute significantly to the design of the European third-generation detector.

We are looking for students for MSc theses

- Career

High power lasers for current and future gravitational-wave detectors

The interferometric measurement of the effects of gravitational waves requires custom-made high power laser sources with extremely low power and frequency noise. We have developed and built these laser sources for the current network of gravitational-wave detectors together with the Laser Zentrum Hannover.

High power laser development at 1064 nm

Current and future gravitational-wave detectors need narrow linewidth, high power laser sources with low noise and high beam quality to reach a high detector sensitivity at high frequencies.

Laser stabilization

The continuous improvement of ground-based gravitational-wave detectors (GWDs) and the preparations for next GWDs place high demands on their stabilized laser sources. The laser source for the interferometric measurement in the GWDs has to be single mode, lineary polarized, single frequency and with low laser noise. Its frequency noise and power noise have to be actively and passively stabilized to reach the required stability.

Pre-stabilized laser source for ETpathfinder

We provide the pre-stabilized laser source with a wavelength of 1550 nm for ETpathfinder, the Einstein Telescope test facility currently being set up in Maastricht.

Enhancing laser power stabilization with squeezing

We achieved the first demonstration of a squeezed light-enhanced laser power stabilization. Its performance is equivalent to an almost tenfold increase of detected laser power in a classical scheme.

Laser power stabilization via radiation pressure

This experiment is about a new radiation pressure based scheme to sense and stabilize the power fluctuations of a laser beam.

Quantum correlation measurement of power fluctuations

The ‘quantum correlation measurement’ (QCM) technique investigated here presents a simple alternative for out-of-loop laser power noise detection.

Laser stabilization at 1550 nm

We investigate performance and capabilities of laser stabilization for laser sources at a wavelength of 1550 nm for their possible use in future gravitational-wave detectors and look into power scaling in collaboration with the Laser Zentrum Hannover e.V..

Lasers for ALPS

We are providing major parts of the experimental setup for ALPS II (Any Light Particle Search II) while conducting pathfinder laboratory experiments. ALPS II at DESY in Hamburg is looking for a new, light-weight, set of elementary particles.

ALPS II control system prototype

AEI has built and is operating a miniaturized 1-meter prototype of ALPS II to investigate fundamental concepts of the experiment.

70 Watt laser system for ALPS II

The main AEI ALPS II hardware contribution is the 70 Watt high power laser system and components that shape the laser beam to match the Eigenmode of the ALPS II production cavity.

Squeezed light

The use of squeezed vacuum states of light is a key component of current and future gravitational-wave detectors, which will be limited by quantum mechanical noise over a large part of their frequency band.

Squeezed light lasers for current and future gravitational-wave detectors

We have developed and built squeezed light sources for GEO600 and Virgo. We also develop such technology for next-generation gravitational-wave detectors.

Generation of strongly squeezed states

We develop sources for highly squeezed states of light to improve precise metrological applications. We hold the world record for squeezed light states at a level of 15 dB.