In a paper Published earlier this month in Physical Review Letters, a team of physicists led by Jonathan Richardson From the University of California to Riverside, shows how the new optical technology can extend the range of detection of gravitational waves such as the observatory with gravitational laser interfeing waves, or LigoAnd will pave the way for future observatories.
Since 2015, observatories like Ligo have opened a new window on the universe. Plans for future upgrades to 4 -kilometer Ligo detectors and the construction of a 40 -kilometer new generation observatory, Cosmic exploreraims to push the horizon of detection of gravitational waves until the early days of the history of the universe, before the formation of the first stars. However, the realization of these plans depends on the realization of the levels of laser power exceeding 1 megawatt, far beyond the capacities of Ligo today.
The research document reports a breakthrough that will allow gravitational waves to reach extreme laser powers. It presents a new approach of low noise adaptive optical optics which can correct the limiting distortions of the main mirrors of 40 kilograms of Ligo which occur with the increase in laser power due to heating.
Richardson, deputy professor of Physics and astronomyexplains the results of the newspaper in the following questions and answers:
What are gravitational waves?
Gravitational waves are a new way of observing the universe. They are predicted by the general relativity equations. When massive objects accelerate or collided in the universe, the distortions of the space-time fabric propagate like undulations in a pond at the speed of light. These distortions are gravitational waves and, like electromagnetic waves, they carry energy and momentum. We now have a lot of information on extreme astrophysical objects such as the black holes that create them and on the physics of the underlying nature of the space-time that these waves cross to reach us.
How does Ligo work?
Ligo is one of the largest scientific equipment in the world. It consists of two laser interferometers 4 kilometers by 4 kilometers long. One of these interferometers is in the interior state of Washington; The other is outside Baton Rouge, in Louisiana. These sisters sites operate in tandem, passively listening to all the distortions of space-time which could spread through earth as a gravitational wave.
So far, Ligo has seen around 200 events of stellar compact objects collided and merge with each other. The overwhelming majority were mergers of two black holes, but we also saw mergers of neutron stars. I hope we can one day detect a completely unexpected and unexpected source. If you look at the history of astronomy, whenever we have developed electromagnetic telescopes which can observe a wavelength of light different from what has never been observed before, we see the universe literally under a New day and have almost always discovered new types of objects visible in this wavelength but not in others. I hope the same is true for gravitational waves.
Tell us about the instrument you have developed in your laboratory that has LIGO applications.
My objective at UCR is to develop new types of Laser adaptive optical technology to overcome very fundamental physics limitations to the sensitivity that we can make detectors like Ligo. In the majority of gravitational wave signal frequencies, we can see from the soil, almost all are limited in sensitivity by quantum mechanics, by the quantum properties of laser light itself that we use in the interferometer for Rebound on mirrors. The instrument that we have developed in my laboratory is designed to provide optical precision corrections directly to the main mirrors of Ligo interferometers. Our instrument is designed to sit a few centimeters in front of the reflective surface of these mirrors and project a very low corrective infrared radiation on the front surface of the mirror. This is the first prototype of a completely new type of approach which uses optical principles not of imaging, which have never been used in the detection of gravitational waves before.
What is Cosmic Explorer?
Cosmic Explorer is the American concept of a new generation gravitational wave observatory, after Ligo. It will be 10 times the size of Ligo, so it is 40 interferometers 40 kilometers long. It will be the largest scientific instrument ever built. During their sensitivity to design, these detectors will see the universe at earlier moments when the first stars were formed, when the universe was approximately 0.1% of its current age of 14 billion years. We will be able to see a snapshot of the universe at a very early stage.
In short, what is the research document discussed?
The article demonstrates that high precision optical corrections are essential to extend our gravitational waves of the universe. It presents the potential implications of the impact we expect from our new technology in the next generation of Ligo and in the years beyond. Above all, the article shows that this type of technology is necessary and adequate to allow much higher levels of laser power in circulation in Ligo detectors than ever before. We expect this technology, and the future versions of it will be able to obtain more power in the interferometer.
Why is it important to do this research?
This research promises to answer some of the deepest questions of physics and cosmology, such as the speed at which the universe develops and the true nature of black holes. There are currently two measures of contradiction of the local expansion rate of the universe, which gravitational waves can potentially resolve. Gravitational waves will also provide extremely high precision measures of detailed dynamics around the horizons of black holes events, allowing us to make direct tests of classic general relativity and alternative theories.