Speaker
Description
Quantum noise broadly limits the sensitivity of gravitational-wave detectors like LIGO, with optical losses representing the primary barrier to achieving 10dB of broadband measured squeezing. While O4 demonstrated ~6 dB of measured squeezing at high frequencies using frequency-dependent squeezing via a 300-meter filter cavity [1,2], reaching 10 dB requires loss below 8% - far below the current 20-30%. At UC Berkeley, we are developing a tabletop setup for tunable frequency-dependent squeezing and broadband quantum noise reduction through several complimentary efforts, such as optimizing the optical parametric oscillator (OPO) geometry and crystal parameters to maximize escape efficiency and robustness; designing a tunable filter cavity for optimal frequency-dependent squeezed angle rotations around lower frequencies; and developing in-situ squeezing diagnostics to disentangle incoherent optical losses from coherent squeezed quadrature rotations from e.g. mode-mismatch or misalignments [3]. Together, we aim to test squeezing diagnostics, methods, and techniques for reaching next-generation detector sensitivities.