100 GHz bandwidth, 1 volt integrated electro-optic Mach–Zehnder modulator at near-IR wavelengths

Abstract

Integrated photonics at near-IR (NIR) wavelengths currently lacks high bandwidth and low-voltage modulators, which add electro-optic functionality to passive circuits. Here, integrated hybrid thin-film lithium niobate (TFLN) electro-optic Mach–Zehnder modulators (MZM) are shown, using TFLN bonded to planarized silicon nitride waveguides. The design does not require TFLN etching or patterning. The push–pull MZM achieves a half-wave voltage length product (V π L) of 0.8 V.cm at 784 nm. MZM devices with 0.4 cm and 0.8 cm modulation length show a broadband electro-optic response with a 3 dB bandwidth beyond 100 GHz, with the latter showing a record bandwidth to half-wave voltage ratio of 100 GHz/V and a high extinction ratio exceeding 30 dB. Such fully integrated high-performance NIR electro-optic devices may benefit data communications, analog signal processing, test and measurement instrumentation, quantum information processing and other applications.