Fiber compatible fast acousto-optic modulator using a gradient index lens as the interaction medium

A novel fiber-compatible acousto-optic modulator is described in which the interaction between the optical and acoustic waves occurs in a graded-index lens which can also function as an]] expanded-beam" fiber-to-fiber connector in the case of a half-pitch device, or as a collimator in the case of a quarter-pitch device. Initial results using a quarter-pitch lens are diffraction efficiences of 3%, and diffraction loss of 7%, using 0.5 W power of 80 MHz rf under cw operation and under pulsed operation, using pulse widths down to 40 ns. A 14 ns switching time was measured.