BROAD-BAND REFLECTION TRAVELING-WAVE LINBO3 MODULATOR

A velocity matched traveling-wave Mach-Zehnder interferometer (MZI) in LiNbO3, operating in reflection, is reported and drive voltages are c ompared to those for single-pass devices of the same length. The devic e achieves double-pass operation by simultaneously reflecting the opti cal and RF waves. Broad-band operation to 20 GHz with drive voltages f rom 0.5 to 1 V (<0.5 GHz) to similar to 4.5 V (at 20 GHz) is observed with the reflection device. This performance is superior to that of th e single-pass device, which has drive voltages of 2.1 V (dc) to simila r to 4.5 V (at 20 GHz).