DEVICE FOR MANIPULATING PROPERTIES OF ELECTROMAGNETIC RADIATION

摘要

A device for manipulating the properties of a laser beam comprises a glass- block or slab (7) that is mounted on a piezo-electric crystal. The piezo-electric crystal is arranged so as to vibrate the block or slab (7) in a linear reciprocating fashion along a direction (8). This motion of the glass block or slab 7 causes Fresnel drag on a laser beam passing through the glass block (7), thereby inducing a phase (and frequency) shift in the beam as it passes through the block or slab (7), which is proportional to the velocity of the block or slab (7). This can be used to, e.g., dither the frequency or phase of the beam in use.