Accession Number : ADP002447

Title :   Ultra-Stable Laser Clock, Second Generation,


Personal Author(s) : Facklam,R.

Report Date : 1983

Pagination or Media Count : 6

Abstract : This paper is a continuation of the work presented at the Frequency Control Symposium. The ring laser used is a Raytheon RB-25 which is a non-planar He-Ne laser whose optical path length is 25.69 cm. The best data from last year was taken on laser no. 68 which was an operational prototype RLG. Two main effort sources were evaluated; the quantum limit imposed by the Heisenburg uncertainty principle, and the temperature induced drift in the frequency shift caused by the Faraday rotator. The current work does not attempt to reduce the quantum limit, which could be done by increasing the laser power and/or the cavity Q. Improvements in the quantum limit would require building a new laser and funding was not available for a new laser. The current effort addresses improvement in the Faraday rotator frequency drift as a function of temperature. The new electronics has one detector to measure the clockwise beat frequency and a second to measure the counterclockwise beat frequency. The two beat frequencies are summed and then divided down in frequency to near 5MHz.

Descriptors :   *Clocks, *Gyro compasses, *Ring lasers, Frequency standards, Frequency, Lasers, Accuracy, Measurement

Distribution Statement : APPROVED FOR PUBLIC RELEASE