InP-Based Mach–Zender Modulator with Adjustable Extinction Coefficient

Development of the Mach–Zender electrooptic modulator with adjustable extinction coefficient provided by electrical tuning of the input splitter based on multimode interferometer. Electrooptical bandwidth of the modulators was higher than 32 GHz, modulus of electric signal reflectance from the input was not higher than –12 dB within the range up to 43 GHz, half-wave voltage was equal to 2.8 V at 1550 nm. However, electrical tuning of the input splitter extended the extinction ratio of the modulator from the initial 21.5–29.5 dB.