A squeezed light source operated under high vacuum

Abstract

Non-classical squeezed states of light are becoming increasingly important to a range of metrology and other quantum optics applications in cryptography, quantum computation and biophysics. Applications such as improving the sensitivity of advanced gravitational wave detectors and the development of space-based metrology and quantum networks will require robust deployable vacuum-compatible sources. To date non-linear photonics devices operated under high vacuum have been simple single pass systems, testing harmonic generation and the production of classically correlated photon pairs for space-based applications. Here we demonstrate the production under high-vacuum conditions of non-classical squeezed light with an observed 8.6 dB of quantum noise reduction down to 10 Hz. Demonstration of a resonant non-linear optical device, for the generation of squeezed light under vacuum, paves the way to fully exploit the advantages of in-vacuum operations, adapting this technology for deployment into new extreme environments.

Quantum-Enhanced Advanced LIGO Detectors in the Era of Gravitational-Wave Astronomy

“…To prevent this effect, the Advanced LIGO squeezer has a unique design that places core components on a seismically isolated platform housed inside the main LIGO vacuum envelope [28,29]. Combined with a bowtie geometry for the optical parametric oscillator (OPO) [30,31] that generates the squeezing, and the use of an additional Faraday isolator on the squeezed vacuum injection path, the system provides a backscatter isolation ratio measured to be 130 dB, which [20], with O3 measurements detailed in Ref. [4]).…”

Ultra-low phase noise squeezed vacuum source for gravitational wave detectors

“…To our knowledge, this is the lowest phase noise ever measured with a squeezed vacuum source [16,18,[22][23][24]. Low phase noise performance is achieved by combining an improved control scheme with a nearly monolithic optical parametric oscillator (OPO) with an intrinsically low length noise.…”

“…The OPO, which is based on the design used in [24], is UHV compatible, so it can be mounted on a suspended table within the Advanced LIGO vacuum envelope to reduce backscatter noise. Details of its construction and optical parameters can be found in [28].…”

“…Here, both quadrature variances are measured at several non-linear gains and the data are fitted to Eq. (2) in order to determine the total loss and phase noise, as typically done to characterize squeezed light sources [15,16,18,[22][23][24]31].…”

Audio-Band Frequency-Dependent Squeezing for Gravitational-Wave Detectors

“…Based on the results presented here, previous experimental work [11,13,24,36], and extensive theoretical studies [14,18,37], the authors and other members of the LIGO Laboratory have begun the process of designing and building a full-scale prototype frequency-dependent squeezed light source for Advanced LIGO.…”