Abstract: A compact frequency standard having a dielectrically loaded microwave resonant cavity. One embodiment uses light from a single laser at the frequency that causes F=4.fwdarw.F'=5 transitions in cesium, circularly polarizes a portion of the light to optically pump a cesium beam and uses another linearly polarized portion of the light to detect fluorescence after the beam passes through the microwave cavity. The microwave cavity is preferably dielectrically loaded cavity which is resonant in the TE.sub.011 or TE.sub.013 modes. The dielectric within the microwave cavity is in the form of a hollow cylinder with varying sidewalls displacing the effective axis of the microwave cavity from the geometric axis to produce a Ramsey resonance in a single cavity and creating inhomogeneities in the static field that cause narrow resonance anomalies in the cesium spectrum, which resonances may be locked onto to provide improved frequency standards.

Abstract: A mounting device (10) includes first (28) and second (32) levers that are disposed between a base plate (12) and a mounting plate (20) and that are attached to the base plate by flexible metal hinges (36a and 36b). First (56a) and second (56b) adjustment devices extend through the base plate (12) and selectively adjust the angles of inclination of the levers (28 and 32). The levers (28 and 32) each change the angular inclination of the mounting plate (20) about one axis by a smaller angle than the angular change received by that (28 or 32) lever.

Abstract: A compact, self-contained and economical frequency standard uses a passive hydrogen maser to provide an accurate, repeatable, and stable standard frequency. The hydrogen dissociator and microwave cavity of the maser and circuit means coact to reduce the frequency variations possible with prior systems and to promote and emphasize the energy transfer from hyperfine hydrogen atoms to the frequency standard for its stabilization. The dissociator is accurately alignable to transfer its hyperfine hydrogen atoms of a selected state to a microwave cavity; and the microwave cavity is formed by dielectric surfaces which have been coated with a conductive coating in a predetermined configuration to suppress oscillation in undesirable modes.