title: Design and operation of a very large ring laser gyroscope.
abstract: The design and initial operation of a vertical square He-Ne ring laser G0 with a perimeter of 14 m is discussed. This builds on earlier demonstrations of the feasibility of large ring lasers (perimeter approximately 4 m) for single-mode gyroscope operation and with lesser pulling than navigation gyroscopes. With servoing of the rf excitation to yield single-mode operation, G0 gave a quality factor 1 x 10(12) and a Sagnac line with a frequency of 287.8 +/- 1.0 Hz induced by Earth rotation Omega(E). This has confirmed some vital questions over the feasibility of very large gyroscopes for geodetic measurements at the level of 10(-9) Omega(E).
authors.affiliation: Department of Physics and Astronomy, University of Canterbury, Private Bag 4800, Christchurch, New Zealand.
authors.forename: C H
authors.initials: CH
authors.lastname: Rowe
authors.forename: U K
authors.initials: UK
authors.lastname: Schreiber
authors.forename: S J
authors.initials: SJ
authors.lastname: Cooper
authors.forename: B T
authors.initials: BT
authors.lastname: King
authors.forename: M
authors.initials: M
authors.lastname: Poulton
authors.forename: G E
authors.initials: GE
authors.lastname: Stedman