High-bandwidth CMOS-voltage-level electro-optic modulation of 780 nm light in thin-film lithium niobate

TL;DR

This paper demonstrates a high-bandwidth, low-voltage Mach-Zehnder interferometer on lithium niobate for visible-near-infrared wavelengths, enabling scalable quantum and atomic systems with integrated photonics.

Contribution

It introduces a CMOS-compatible, high-bandwidth electro-optic modulator platform on lithium niobate for VNIR wavelengths, advancing integrated photonics for quantum and atomic applications.

Findings

Achieved 2.7 GHz electro-optic bandwidth

Full-swing voltage of 4.2 V compatible with CMOS

Compact device area of 0.35 mm²

Abstract

Integrated photonics operating at visible-near-infrared (VNIR) wavelengths offer scalable platforms for advancing optical systems for addressing atomic clocks, sensors, and quantum computers. The complexity of free-space control optics causes limited addressability of atoms and ions, and this remains an impediment on scalability and cost. Networks of Mach-Zehnder interferometers can overcome challenges in addressing atoms by providing high-bandwidth electro-optic control of multiple output beams. Here, we demonstrate a VNIR Mach-Zehnder interferometer on lithium niobate on sapphire with a CMOS voltage-level compatible full-swing voltage of 4.2 V and an electro-optic bandwidth of 2.7 GHz occupying only 0.35 mm$^2$. Our waveguides exhibit 1.6 dB/cm propagation loss and our microring resonators have intrinsic quality factors of 4.4 $\times$ 10$^5$. This specialized platform for VNIR integrated photonics can open new avenues for addressing large arrays of qubits with high precision and negligible cross-talk.