Ultra Wideband Dual-Output Thin Film Lithium Niobate Intensity Modulator

This paper presents the design, optimization, fabrication, and characterization of a dual-output, wideband, thin-film lithium niobate Mach-Zehnder Modulator (TFLN-MZM). The device is designed with ridge etched waveguides for operation at a 1. 55 m wavelength. The dual-output is achieved using a 2×2 multi-mode interference (MMI) splitter with an extinction ratio (ER) of over 40 dB. The measured DC half-wave voltage (V _) is 1. 02 V. To achieve wideband operation, segmented electrodes are optimized to provide both wideband index matching and low loss. Accordingly, the measured 3 dB bandwidth is 95 GHz and the radio-frequency (RF) electrode loss is 0. 24 dB/ (cm˙GHz ^1/2). The motivation for this device is in balanced microwave photonic links (MPLs) for Radio-Frequency-over-Fiber (RFoF) applications.