Fig. 4: High-Bandwidth Phase Modulator for Frequency Shifting.
From: A thin film lithium niobate near-infrared platform for multiplexing quantum nodes
a Schematic of phase modulator utilizing segmented electrodes to achieve high-bandwidth EO performance. An input optical signal is frequency shifted using EO serrodyning, where a linear increase in optical phase is approximated via a periodic sawtooth wave whose amplitude corresponds with a phase of 2π. b Half-wave voltage (Vπ) as a function of frequency for a 1 cm phase modulator, showing a 3-dB EO bandwidth exceeding 40 GHz (~100 GHz simulated). c Frequency spectrum of light transmitted through the phase modulator with the serrodyne electrical signal turned off (blue) or on (red), demonstrating a high-efficiency (>90%) 1 GHz frequency shift. d Serrodyne shift efficiency as a function of frequency shift, showing efficiencies greater than 50% for frequency shifts up to 15 GHz.
