Non-Reciprocal Frequency Contributions from the Active Medium in a Ring Laser

Alexander A. Velikoseltsev, Karl Ulrich Schreiber, Jan Kodet, Jon Paul R. Wells

Research output: Contribution to journalArticlepeer-review


Under ideal conditions, the optical path for the two counter-propagating beams in a square ring laser cavity is expected to be entirely reciprocal. This property, together with the absence of any moving parts in the gyro, makes ring lasers a very useful rotation-sensing device. For a typical aircraft application, a sensor stability of the order of 0.01 (Formula presented.) /h and a resolution of 1 ppm is required. The demands for inertial rotation sensing in space geodesy are three orders of magnitude higher. Therefore, the perturbations from the presence of the active laser gain medium inside the cavity cannot be ignored. While these perturbations can be sufficiently contained in aviation gyros due to the much lower requirements, they cause a notable bias in large ring laser gyroscopes for the observation of the instantaneous rotation rate of the Earth. In this paper, we report on an improved model for bias stability from the presence of the laser gain medium in the gyro cavity of the large ring laser “G” at the Geodetic Observatory Wettzell. Typical values between 5 and 10 ppB are obtained over several months.

Original languageEnglish
Article number1241
Issue number11
StatePublished - Nov 2023


  • Earth rotation
  • inertial rotation sensing
  • laser gain medium
  • ring laser


Dive into the research topics of 'Non-Reciprocal Frequency Contributions from the Active Medium in a Ring Laser'. Together they form a unique fingerprint.

Cite this