Internal body mounted system for isolation of, in one degree of freedom, a beam projected from an optical system which is subject to rotational vibration

摘要

The system includes an inertial body on which is mounted a mirror, which together are mounted for rotation by a gimbal bearing element. The gimbal bearing element is part of a base system which further includes a light beam source, such as a laser. The mirror is positioned on the inertial body so that it is at an angle of 45° relative to the axis of the gimbal bearing element. The inertial body, which can be represented by a dumbbell-shaped equivalent mass, is oriented so that the path of the light beam from the light source is coincident with the gimbal axis, i.e. such that the light beam strikes the mirror. A yaw-like disturbance, i.e. a rotational vibration about the Z coordinate axis, affecting the base system, and hence the light beam source and gimbal bearing element as well, is converted into a rotational movement of the inertial body and the mirror about the axis of percussion, which, in the embodiment shown, causes a rotation of the reflected beam about the Y coordinate axis. The reflected beam impinges on a second mirror, which is positioned at a 90° angle relative to the mirror on the inertial body. The rotation of the reflected beam compensates for the effect of the disturbance about the Z axis on the beam, so that the beam reflected from the second mirror remains steady in the far field.