Optical system for recording or replicating hologram

Abstract

The invention provides a hologram recording or replicating optical system wherein a misalignment-with-time of the center of a laser generated beam is automatically corrected so that the color balance in a color hologram surface, for instance, can be well maintained with no disturbance. In the hologram recording or replicating optical system for irradiating a photosensitive material 20 with a beam from a laser 31 through a pinhole 10, a beam position correcting mechanism 32 and a beam splitter 33 are located in an optical path between the laser 31 and the pinhole 10, and a laser beam position detector 35 is located at a position in an optical path split by the beam splitter 33 and conjugate to the pinhole 10, so that the beam position correcting mechanism 32 can be operated on the basis of a beam position error signal obtained from the laser beam position detector 35 to keep the position of the beam incident on the pinhole 10 always constant.

Dependencies are inferred from the claim text.