High-performance optical modulator with a wide center electrode and thin x-cut LiNbO3 substrate

We propose an excellent large-bandwidth back-slot lithium niobate (LN) modulator with a wide center electrode of typically 50 μm or wider and relatively thin electrodes. From the calculation, a modulator with a 3-dBe bandwidth of 34 GHz and a half-wave voltage of 2.0 V for a 50-/spl Omega/ characteristic impedance system was realized theoretically. This means when their half-wave voltages are identical, by applying a wider electrode, the modulator bandwidth becomes 2.6 times larger than that of a conventional one. We also confirmed experimentally that the wide center electrode structure is effective for back-slot LN modulators.