Abstract: A magneto-optic reading apparatus includes a laser light source for generating a linearly polarized light beam and a quarter-wave plate which converts the linearly polarized light beam into a circularly polarized light beam. A beam splitter separates the circularly polarized light beam into a first beam which passes therethrough and a second beam which is reflected. An objective lens converges the first beam so as to scan one of the data tracks of a magneto-optic recording element. The information written along the scanned data track causes the polarization of the first beam to be modulated as the first beam is reflected by the recording element toward the first beam splitter. The first beam splitter further separates the first beam into a third beam which passes therethrough and a fourth beam which is reflected.

Abstract: A lens combination set in front of an optical fiber terminal head of an optical fiber fine displacement detecting system to focus a real image of the optical fiber terminal head so as to extend the mounting range of the head relative to the object in detection and avoid any possible damage due to collision of the object with the head. The lens combination focuses the light rays from the optical fiber terminal head to form a real image outside the lens combination. The reflected light rays from the object mounted around the real image are focused by the lens combination and sent back to the detecting system through the optical fiber terminal head. Therefore, sufficient safety range is obtained between the lens combination and the object in detection without affecting the normal operation of the detecting system.