The first detection of gravitational waves from a binary black hole inspiral by LIGO in September 2015 heralded the beginning of a new age in gravitational wave astronomy. The detection of a binary neutron inspiral in August 2017 and has now opened up a new era of multi-messenger astronomy. To increase the sensitivity of future gravitational wave detectors, a change to cryogenic silicon test masses and an increase in laser power may be required. Silicon is a compelling choice as it has high thermal conductivity at cryo- genic temperatures, which reduces temperature gradients generated by optical absorption. Additionally, at 123 K, its thermal expansion coefficient crosses zero. Thus, near this temperature, thermo-elastic distortion of the mirror surface should be drastically reduced, as would the effect of thermo-elastic noise due to thermodynamic temperature fluctuations. However, the adoption of silicon for the optical substrates would necessitate a shift of operating wavelength from 1064 nm to >1.3 μm where silicon is transparent. While potential wavelengths include ca. 1.55 μm and 2.0 μm, the longer wavelengths may be preferred due to lower scattering loss and coating absorption.
The next-generation gravitational wave detectors aim to enhance our understanding of extreme phenomena in the Universe. The high-frequency sensitivity of these detectors will be maximized by injecting squeezed vacuum states into the detector. However, the performance advantages offered by squeezed state injection can be easily degraded by losses in the system. A significant source of loss is the mode mismatch between optical cavities within the interferometer. To overcome this issue, new actuators are required that can produce a highly spherical wavefront change, with minimal higher order aberrations, whist adding low phase noise to the incident beam.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.