Abstract: The apparatus of this invention uses a two-branched linear gas laser having two end mirrors and a third mirror positioned at a bend in the two-branched laser cavity. The laser cavity is bent through an angle, .theta., usually ninety degrees. With a bent cavity, frequency splitting occurs, and that splitting is a function of the angle .theta.. The end mirrors and laser cavities are supported upon two beams relative to the third mirror, and or both of these beams are cantilevered relative to the third mirror. Each flexible beam supports a proof mass. Under acceleration, the angle .theta. changes in a reversible and reproducible manner. The beams are converted into properly oriented planar polarized waves, and the specially polarized beams then are delivered to laser beam sensors to produce electrical output signals that are a measure of the frequency splitting between the two laser modes and a measure of sensed acceleration.

Abstract: An annular laser having an elongated centrally located flashlamp enclosed in a quartz tube as well as adjustable and interchangeable laser windows. The position of the flashlamp produces a gain region with a smoothly varying radial intensity distribution with uniform azimuthal output. The mechanism which permits adjustment and interchangeability of the laser windows allows the invention to be utilized as a useful tool in the study of annular optics.