Erlangen 2018 – scientific programme

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Q: Fachverband Quantenoptik und Photonik

Q 62: Poster: Quantum Optics and Photonics V

Q 62.39: Poster

Thursday, March 8, 2018, 16:15–18:15, Redoutensaal

Coherent beam combination and power actuation of high power lasers for gravitational wave detectors — Nina Bode and •Benno Willke — Max Planck Institute for Gravitational Physics, Hannover

The next generation of gravitational wave detectors, like the Einstein Telescope, are designed to reach a high sensitivity at a broad range of frequencies. At high frequencies shot noise is a fundamental limit. As the shot noise limited sensitivity improves with increasing laser power it is proposed to use a 500W laser source with a wavelength of 1064 nm.

Currently available laser sources with such a high power do not fulfill the strong power, frequency and mode stability requirements of gravitational wave detectors. The coherent beam combination of two stable 250W lasers could generate a 500W beam with the required stability.

For demonstration purposes we performed a coherent beam combination of two solid-state laser systems, at a wavelength of 1064nm, with a combination efficiency of 90%.

To handle the high power beams, we developed a fast power actuator working with the effect of frustrated total internal reflexion (FTIR).

The FTIR-actuator produces a reflected and transmitted beam, the power ratio of wich can be adjusted. We characterized the reflected and transmitted beam and found that the actuator does not signifancantly influence the spatial beam shape and the noise of both beams.