Search arXiv⌕ Search
Home/Archive/arXiv

arXiv · 1901.09666

A compact actively damped vibration isolation platform for optical experiments in ultra-high vacuum

Álvaro Fernández-Galiana·Lee McCuller·Jeff Kissel·Lisa Barsotti·John Miller·Maggie Tse·Matthew Evans·Stuart M. Aston·Thomas J. Shaffer·Arnaud Pele·Janeen H. Romie·Betsy Weaver·Richard Abbott·Peter Fritschel·Nergis Mavalvala·Fabrice Matichard
View original source ↗Read source document ↗Export metadata ↓

Abstract

We present a tabletop six-axis vibration isolation system, compatible with Ultra-High Vacuum (UHV), which is actively damped and provides 25 dB of isolation at 10 Hz and 65 dB at 100 Hz. While this isolation platform has been primarily designed to support optics in the Laser Interferometer Gravitational-Wave Observatory (LIGO) detectors, it is suitable for a variety of applications. The system has been engineered to facilitate the construction and assembly process, while minimizing cost. The platform provides passive isolation for six degrees of freedom using a combination of vertical springs and horizontal pendula. It is instrumented with voice-coil actuators and optical shadow sensors to damp the resonances. All materials are compatible with stringent vacuum requirements. Thanks to its architecture, the system's footprint can be adapted to meet spatial requirements, while maximizing the dimensions of the optical table. Three units are currently operating for LIGO. We present the design of the system, controls principle, and experimental results.

Explore related subjects

physics.ins-detastro-ph.IMphysics.optics

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Álvaro Fernández-Galiana, Lee McCuller, Jeff Kissel, Lisa Barsotti, John Miller, Maggie Tse, Matthew Evans, Stuart M. Aston, Thomas J. Shaffer, Arnaud Pele, Janeen H. Romie, Betsy Weaver, Richard Abbott, Peter Fritschel, Nergis Mavalvala, Fabrice Matichard. 2019-07-24. A compact actively damped vibration isolation platform for optical experiments in ultra-high vacuum. https://doi.org/10.1088/1361-6382%2Fabb5c2

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

Development of an Extensible Unified Control System Using the STARS Framework and Common Commands for Detector Control

A zooming optical system comprising two Fresnel zone plates (FZPs) was developed and installed at the AR-NE1A beamline of the Photon Factory, High Energy Accelerator Research Organization (KEK), Japan. To ensure reliable and versatile operation, we implemented a dedicated control architecture based on the Simple Transmission and Retrieval System (STARS) framework and the newly proposed STARS Common Commands for Detector Control (CCDC)---a data-acquisition (DAQ) state model and command set designed specifically for detector control. The system serves both as a practical control system for the zooming optics and as a demonstration of modular extensibility using STARS and detector interoperability through CCDC. The system has been commissioned, and its performance has been verified at the AR-NE1A beamline. The architecture enables flexible configuration of optical components and provides a unified interface for both routine operation and advanced experimental protocols.

physics.ins-det↗
arXiv2026

Agentic TCAD Calibration Workflow for Oxide Semiconductor Transistors

Experimental TCAD calibration is essential for predictive technology modeling of emerging oxide semiconductor transistors. However, it remains time-consuming and expert dependent because of model ambiguity. Multiple physical models and parameter sets can reproduce the same measured transfer characteristics, while local fitting alone cannot uniquely identify the underlying device physics. We present the first demonstration of an agentic TCAD calibration workflow for a fabricated bottom-gate In--W--O (BG-IWO) transistor. Starting from the measured transfer curve and device information, the workflow uses measurement--TCAD residuals and local sensitivity tests to select bounded parameter corrections or evaluate additional physical models, and accept only updates that improve device metrics. The LLM agent orchestrates the workflow, while Sentaurus governs the device physics. For the 2\%-W reference device, five agent-suggested updates yield a fixed calibrated model, reducing the multi-metric device objective $J$ by 14.3$\times$. Maximum $V_{\mathrm{th}}$/$I_{\mathrm{on}}$ errors are 36.1~mV/0.022 decade for varying-drain-bias tests and 46.2~mV/0.062 decade for varying-channel-length tests, demonstrating model transferability across bias and geometry rather than a local parameter fit. W-composition tests provide process-sensitive insight. This agentic workflow provides a faster route to model development for emerging device technologies.

physics.ins-det↗
arXiv2026

Birefringence of AlGaAs/GaAs Coatings under Above-Band-Gap Illumination, GR Noise and Photo-Optic Transfer Function

AlGaAs/GaAs coatings are being considered as coating candidates for gravitational-wave detectors. In this paper we investigate the birefringence properties of this crystalline semiconductor material by modulating the optical illumination on the mirror coating and monitoring the induced birefringence. While the measured low-frequency birefringence values align with previous studies, we observed a frequency-dependent behavior in the illumination-to-birefringence coupling, characterized by a pole increasing with illumination intensity and a gain at zero frequency (DC gain) decreasing with illumination intensity. We developed a generic theoretical model based on a master equation to characterize the measurement results by considering photon-induced electric fields and electro-optic effects. This model can fit the frequency and intensity dependencies of the induced birefringence. Additionally, this model predicts a generation-recombination noise (GR noise) will be observable in the coating birefringence. While the presented measurement cannot predict the exact level of GR noise, for the frequency band and spot sizes relevant for gravitational-wave detectors we expect GR noise to be white below the pole frequency, scale with power the same way laser shot noise does, and for fixed power be independent of spot size.

physics.ins-det↗