FIBER COMPATIBLE FAST ACOUSTOOPTIC 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 gr aded-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 collima tor in the case of a quarter-pitch device. Initial results using a qua rter-pitch lens are diffraction efficiences of 3%, and diffraction los s of 7%, using 0.5 W power of 80 MHz rf under cw operation and under p ulsed operation, using pulse widths down to 40 ns. A 14 ns switching t ime was measured.