Speaker
Dr
Nicholas Lockerbie
(University of Strathclyde)
Description
A simple optical displacement sensor consisting of an infrared LED
source, a photodiode detector, and an occluding ‘flag’, has been
investigated, for potential use in the Advanced LIGO gravitational
wave detectors. A number of different commercially available LEDs
and photodiodes were tried in the displacement sensor, and an
optimal pair was found. A surprising geometrical effect was noted
which allowed the residual noise level to be reduced at low
frequencies, permitting a displacement sensitivity of ~10-10 m/Hz
to be attained at a frequencies in the region of 2 Hz. A novel
optical x2 linear displacement amplifier has also been constructed,
suggesting that the displacement sensitivity might be further
improved by this factor.
The work reported here was carried out in collaboration with the
Institute for Gravitational Research at the University of Glasgow,
the Department of Physics and Astronomy at the University of
Birmingham, and the Rutherford Appleton Laboratory.
Author
Dr
Nicholas Lockerbie
(University of Strathclyde)
