We report here experimental studies of an amplitude modulator using Ti-diffused LiNbO
3branched waveguides. In this paper we present experimental evidence in support of three problem areas connected with the improvement of performance of the device. Solution of the problems has involved the development of a new in-diffusion process to eliminate any background radiation, introduction of a new electrode arrangement which consists of extra electrodes at the branching section to control the splitting action, and finally performing measurements at a longer wavelength (

) to overcome the limitations of available photomasks.