METHOD AND APPARATUS FOR RADIANT ENERGY MODULATION IN OPTICAL FIBERS

摘要

Radiant energy is caused to modulate in phase and frequency in a single mode optical fiber by means of a relatively movable, spatially periodic perturbation. Specifically, an optical grating is mounted on the cladding at a control zone near the core of the fiber. The control zone may be formed by removing a portion of the cladding to form a reduced thickness cladding portion. The grating has its crests oriented generally normal to the optic axis of the optical fiber and the grating is caused to move relative to the optic axis, for example by sliding along the optical fiber. A shear mode piezoelectric transducer may be used to cause the necessary movement.