Departmental Seminar

Catching the Waves in the Sea of Noise: Squeezed Light in Advanced LIGO and Beyond

Ms Nutsinee Kijbunchoo

In 2015, LIGO’s first gravitational wave detection opened up a new window to the universe and marked the beginning of the gravitational-wave astronomy era. In 2017, the first binary neutron star coalescence with electromagnetic counterparts was detected and marked the beginning of multi-messenger astronomy. The advanced LIGO detector has become so sensitive that its performance is broadly limited by quantum noise – the random behavior of photons that are dictated by the Heisenberg Uncertainty Principle called shot noise. Even though the idea of injecting squeezed light to help manipulate the quantum noise in LIGO was first proposed in 1981, it took nearly 4 decades before the squeezed light source was integrated as part of a normal operation in advanced LIGO.In this talk I will discuss a major component of my thesis that highlights work done on the squeezed light source, sensing and control implementation at LIGO Hanford. The result is a robust system that runs 100% of the detector observation time and an improvement of ∼3 dB in the detector sensitivity. With 50% more of the universe’s volume covered, scientists were able to detect new events such as a black hole-neutron star coalescence and a mysterious astronomical object that falls within the mass-gap region.

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Date & time

Wed 23 Mar 2022, 1–2pm


Zoom Meeting ID: 838 5196 4357 Password: 934778


Members of RSPE welcome


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