Beautiful Life

A year ago, people first detected the gravitational waves directly. From the Planck Institute for the Study of Gravitational Physics (Albert Einstein Institute AEI), as well as from the University of Leibniz, Hanover, as well as from the Hannover Laser Center (LZH) laser experts in this discovery played a major , Because they use the high power laser pointer interferometric gravitational wave in the United States. The core instrument in the Observatory has ultra-precision laser technology to detect weak gravitational wave signals.

Now, researchers at the Einstein Institute have proposed two new technologies that will not only further improve the sensitivity of future gravitational wave detectors. The Max Planck Society now also strengthens the development of the third generation of gravitational wave detector laser systems. The Einstein Institute, in cooperation with the Hannover Laser Center, has invested $ 3.75 million in research funding for the next five years to develop the new laser Zentrum, which has received more than $ 3.75 million in research funding for the next five years New lasers and improved its stability. "We've made an important breakthrough," says Professor Benno Willke, who is the head of the Einstein Institute's Laser Development Group. "Our job is to further study another new type of green astronomy laser beam used in interferometric gravitational wave detectors, and we have shown how to improve power stability, that is, the stability of high power lasers used in detectors.

The beam of the gravitational wave detector currently used for all laser systems has a higher strength than the edge of the beam. This will lead to a problem of measurement accuracy of gravitational wave detectors that do not wish to be caused by fluctuations in the specular surface. This so-called thermal noise can be improved by a more uniform laser intensity distribution. In 2013, the team demonstrated how to get a more uniform high-power laser beam, creating the so-called LG33 model. Now, Andreas Noack has completed his master's thesis, Benno Willke's team is trying to apply these 2000mw green laser beams to future gravitational wave detectors.

The first step into the detector is a device called a predictive mode cleaner that optimizes the beam profile and reduces beam jitter. Willke's team found that the new LG33 beam was compatible with the current predictive cleaning model used. The researchers also showed how to solve this problem. They have developed a new pre-cleaning mode that is compatible with the LG33 laser mode. "The design of the next generation of gravitational wave detectors has not yet been completed," Willke said. "So we are testing different types of lasers and finding as many options as possible to achieve the new gravitational wave detectors.With the LG33 laser beam, we are now making a big step forward."

All interference gravitational wave detectors, such as LIGO, VIRGO and GEO600, all rely on burning laser pointer systems and need to keep their high output power stable for a year, and their power fluctuates very little on time scales. Benno Willke's research team has a world-leading position in this research area. They built the laser system GEO600 and advanced LIGO, without such a device, the first direct probe gravitational wave in 2015 was impossible to achieve.

Now, Jonas Junker has further refined the existing power stabilization system in Willke's team of master's studies. A portion of the laser beam is removed to achieve a plurality of distributed distributions of the detectors to accurately determine the total power. If so, the main laser power is corrected accordingly. In their experiments, the scientists expanded the current system, in addition, another photodetector can also control and correct the Gatling laser pointer beam pointing.

In the Einstein Institute, the improved power stabilization solution has been successfully applied to a 10-meter prototype interferometer for a 35-watt 3000mw green laser system. The prototype was modeled and tested by Hannover researchers for the technology of the third generation of detectors, and the quantum mechanics effects were studied in these instruments. Power stability of five times higher than other groups of comparable experiments. This result is very good with the results of an independent desktop experiment.

"Experiments in optical labs that are isolated from the external environment are completely different from the 10m prototype complex experiments, and for the first time we have found that it can be transferred from a level of stability in a desktop experiment," Willke Say. "We found that these photodiode arrays work as expected, which means that it should also be used for the same multi-detector array, applied to advanced LIGO, and to achieve this high stability."