Name: Maryrose Barrios
Position: Postdoctoral Researcher in Physics
Title: Towards Optimal, High-Efficiency Quantum Enhancement in the LIGO Gravitational Wave Detectors
Talk Description: The Advanced LIGO (Laser Interferometer Gravitational-wave Observatory) observatories made the first direct detection of gravitational waves in 2015. In its fourth astrophysical observing run (O4), key hardware improvements, such as the recent upgrade to “frequency-dependent squeezing,” have allowed for the broadband quantum enhancement of detector sensitivity. In the two years of O4, the LIGO detectors have totaled nearly 300 new astrophysical triggers, compared to the 90 events detected after two years of observing at previous sensitivities. To achieve greater levels of quantum noise reduction in the future, detector-wide losses must be reduced to allow fragile quantum states of light to propagate more efficiently through LIGO’s complex kilometer-scale facilities. Our work constructing new output mode cleaner (OMC) cavities for the next observing run has now met target specifications of 98%-99.5% throughput efficiency, compared to current cavities with 95-98% efficiency. This talk will detail the design, fabrication, and table-top performance tests, as well as the installation of these new OMC cavities for higher squeezing levels. These advances pave the way for the upgrade to a new type of readout that would allow for optimal quantum-limited detection of the gravitational-wave signal.
Date: Friday, February 20th, 2026
Time: 3:10 pm – 4:00 pm (talk and questions)
Location: 375 Physics North