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Updated: Apr 24, 2026

The Generation of Higher-order Laguerre-Gauss Optical Beams for High-precision Interferometry
Published on: August 12, 2013
A simple pendulum laser interferometer for determining the gravitational constant
Harold V Parks1, James E Faller2
1JILA, University of Colorado and National Institute of Standards and Technology, Boulder, CO 80309, USA Sandia National Laboratories, Albuquerque, NM 87185, USA harold.parks@nrc-cnrc.gc.ca.
Abstract:
We present a detailed account of our 2004 experiment to measure the Newtonian constant of gravitation with a suspended laser interferometer. The apparatus consists of two simple pendulums hanging from a common support. Each pendulum has a length of 72 cm and their separation is 34 cm. A mirror is embedded in each pendulum bob, which then in combination form a Fabry-Perot cavity. A laser locked to the cavity measures the change in pendulum separation as the gravitational field is modulated due to the displacement of four 120 kg tungsten masses.
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