| 摘要 |
A holographic apparatus capable of utilizing a pulsed laser developing an incompletely coherent light beam for taking holograms, particularly in reflection. The apparatus makes use of a diffuser which is preferably inserted into the unenlarged laser beam for averaging amplitude and phase variations and for scattering the light of the scene beam so that there will be at least a component or portion of the scene beam capable of interfering with a component of the reference beam at each point of the hologram. The pulsed ruby laser may be improved by providing at least one mode selector in the resonant cavity which encloses the ruby rod. This mode selector may, for example, consist of a suitable dye which normally absorbs the light of the laser and becomes transparent when the light intensity exceeds a predetermined amount. Alternatively or in addition a second mode selector may be used which may consist of a resonant reflector such as a Fabry-Perot etalon. The holographic apparatus may be further simplified by utilizing a single lens for reflecting the light of a laser to form a reference beam, while the transmitted light forming the scene beam is diffused by making the opposed surface of the lens into a light diffuser.
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