Nuclear magnetic resonance gyroscope

A rubidium vapour lamp (10) is excited by a radio-frequency energy source. The light emitted by the lamp passes through a glass condenser lens (14) and a Fresnel collimator lens (16) before it passes through an optical interference filter (18). The light passing through a second collimator lens (20) is reflected in a prism (22) and converges at the end of an optical input fibre bundle (24). The light leaving the bundle passes through a circulator polariser (26) and enters into a NMR cell (28). The greatest proportion of the light which is not absorbed in the cell (28) enters into an optical output fibre bundle (36) and passes through a lens (38) to a silicon photodetector (40). The structure (34) of the magnetic field coils consists of a cylindrical coil former of a machinable glass. Magnetic shielding (42) attenuates the influence of external magnetic fields. The gyroscope operates in accordance with the principle of determining the inertial angular velocity of rotation or the angular offset about a sensitive axis of the device in the form of a displacement of the Larmor precession frequency or phase of one or a number of isotopes which have nuclear magnetic moments. The close concentration of the rubidium atoms used during the collisions with the noble-gas atoms has the effect that the rubidium atoms sense a much larger mean magnetic field of the cores of the noble-gas atoms. This provides signals which are much larger than in known devices.