Monolithic thin film lithium niobate electro-optic modulator with over 110 GHz bandwidth

High-performance thin film lithium niobate (LN) electro-optic modulators with low cost are in demand. Based on photolithography and wet etching, we experimentally demonstrate a thin film LN Mach–Zehnder modulator with a 3 dB bandwidth exceeding 110 GHz, which shows the potential of boosting the throughput and reducing cost. The fabricated modulator also exhibits a comparable low half-wave voltage-length product of ∼2.37 V·cm, a high extinction ratio of >23 dB, and the propagation loss of optical waveguides of ∼0.2 dB/cm. Besides, six-level pulse amplitude modulation up to 250 Gb/s is successfully achieved.