Near-infrared integrated thin-film lithium-niobate devices for scalable quantum networks

Solid-state quantum emitters have shown promise as spin-photon interfaces for future quantum networks. However, current state-of-the-art demonstrations are limited to a few emitters due to their variation in optical frequency, which prohibits interfacing spectrally disparate emitters, and inability to efficiently spatially multiplex emitters within a node. One way to overcome these issues is by utilizing electro-optic devices, as they permit ~GHz-bandwidth frequency and spatial shifts without added noise. However, the performance offered by current commercial electro-optic devices still limits their ability to solve these issue.

Here we discuss our work on an integrated thin-film lithium niobate platform to scale solid-state quantum emitters. We demonstrate state-of-the-art electro-optic devices including high efficiency couplers (~1.1dB / facet) and phase and intensity modulators with ultra-low half wave voltages (< 1 Vcm) and high bandwidths (> 40 GHz), all operating at near-infrared wavelengths. With these devices we classically demonstrate path switching of laser pulses with extinction ratios beyond 20 dB and frequency shifting of continuous-wave light beyond 10 GHz. We finally discuss progress towards spatial- and frequency-mode shifting of single photons emitted from atomic defects in diamond.