The Laser Interferometer Gravitational Wave Observatory, or LIGO,
is a national facility responsible for gravitation wave research. Set up as two enormous
interferometers located thousands of kilometers apart, LIGO is responsible for
the detection and measurement of movement thousands of times smaller than a
proton – the most precise measurement taken on Earth.
To achieve the remarkable level of sensitivity necessary to detect gravitational waves, both interferometer’s signals must remain uninterrupted. It’s critical that LIGO’s precision optics system - made up of lasers, mirrors, and a photodetector - must be completely free of contamination, particulates, and residue to guarantee the most accurate results possible.
LIGO's team of scientists tested different cleaning methods, including First Contact Polymer, to determine best practices for the cleaning and protection of LIGO optics.
To compare the results of traditional drag wipe cleaning methods to the First Contact strip coat cleaning system, a test was performed.
On vertical surfaces, Clear First Contact was brushed on, left to dry, and peeled off to reveal an atomically clean surface.
Red First Contact Polymer was used on delicate fused silica LIGO optics, leaving a pristine mirror surface.
Methanol drag wipe cleaning methods left streaks and residue behind.
Figure 1: Cleaning with Methanol Drag Wipe
Using these scatterometer graphs and corresponding average BRDF count as a general measure of cleanliness, First Contact performs better than drag wiping with clean or dirty methanol.
Figure 2: Cleaning with First Contact
Before cleaning – residue and contaminants are present on the surface of the optic.
As the only cleaning method used, First Contact is proven to clean the surface to the molecular level.