The continuous improvement of current gravitational wave detectors (GWDs) and the preparations for next generation GWDs place high demands on their stabilized laser sources. Some of the laser sources ...need to operate at laser wavelengths between 1.5 μm and 2.2 μm to support future detectors based on cooled silicon test masses for thermal noise reduction. We present detailed characterizations of different commercial low power seed laser sources and power amplifiers at the wavelength of 1550 nm with respect to performance parameters needed in GWDs. A combination with the most complete set of actuators was arranged as a master-oscillator power amplifier (MOPA), integrated into a stabilization environment and characterized. We present the results of this characterization that make this stabilized MOPA a highly relevant prototype for future GWDs as well as a low noise light source for other experiments in high precision metrology.
This paper reviews some of the key enabling technologies for advanced and future laser interferometer gravitational wave detec- tors, which must combine test masses with the lowest possible optical ...and acoustic losses, with high stability lasers and various techniques for suppressing noise. Sect. 1 of this paper presents a review of the acoustic properties of test masses. Sect. 2 reviews the technology of the amorphous dielectric coatings which are currently universally used for the mirrors in advanced laser interfer- ometers, but for which lower acoustic loss would be very advantageous. In sect. 3 a new generation of crystalline optical coatings that offer a substantial reduction in thermal noise is reviewed. The optical properties of test masses are reviewed in sect. 4, with special focus on the properties of silicon, an important candidate material for future detectors. Sect. 5 of this paper presents the very low noise, high stability laser technology that underpins all advanced and next generation laser interferometers.
The ALPS Collaboration runs a “light shining through a wall” (LSW) experiment to search for photon oscillations into “weakly interacting sub-eV particles” (WISPs) inside of a superconducting HERA ...dipole magnet at the site of DESY. In this paper we report on the first successful integration of a large-scale optical resonant cavity to boost the available power for WISP production in this type of experiments. The key elements are a frequency tunable narrow line-width continuous wave laser acting as the primary light source and an electronic feed-back control loop to stabilize the power build-up. We describe and characterize our apparatus and demonstrate the data analysis procedures on the basis of a brief exemplary run.
Collinear coherent combination of multiple single frequency fiber amplifiers is a promising approach to realize the high power laser sources required for 3rd generation gravitational wave detectors ...(GWD), as long as the stringent requirements on the beam quality and noise properties can be met. Here, we report the beam quality and noise properties of two coherently combined 10 W single frequency amplifiers with respect to the requirements of GWD. The combining efficiency was larger than 95% with 97% of the combined beam in the fundamental spatial mode. There was no significant noise increase compared to the fluctuations of the single amplifier.
The advanced LIGO gravitational wave detectors need high power laser sources with excellent beam quality and low-noise behavior. We present a pre-stabilized laser system with 70 W of output power ...that was used in the third observing run of the advanced LIGO detectors. Furthermore, the prototype of a 140 W pre-stabilized laser system for future use in the LIGO observatories is described and characterized.
Advanced gravitational wave detectors require highly stable, single mode, single frequency and linear polarized laser systems. They have to deliver an output power of ∼200 W and need to provide ...suitable actuators for further stabilization via fast, low noise feedback control systems. We present such a laser system based on sequential Nd:YVO
4
amplifiers and its integration into a typical laser stabilization environment. We demonstrate robust low noise operation of the stabilized amplifier system at 195 W, which makes it a viable candidate for use in gravitational wave detectors.
PDF
