In this paper we report the realization of a ridge waveguide linear mode confinement modulator using reactive ion-beam etching (RIBE). With the help of a design analysis, the modulation characteristics are predicted. Along with the measured modulation characteristics, preliminary results of the calibration of ion-beam etching in

-cut LiNbO
3by Ar and a mixture of Ar and CHF
3are presented. Differential etching rates between photoresist and LiNbO
3of as high as 7 are obtained. Using the proposed design of a ridge waveguide linear modulator, a linear modulation of over 67 percent is measured.