Broadband quasi-phase matching in MgO: PPLN thin film

TL;DR

This paper demonstrates broadband, high-efficiency quasi-phase matching second harmonic generation in MgO: PPLN thin films, enabling tunable, chip-scale quantum photonics applications with a bandwidth up to 2 THz.

Contribution

First experimental demonstration of broadband, reconfigurable quasi-phase matching SHG in MgO: PPLN thin films with tunable wavelengths and large bandwidth.

Findings

Achieved up to 2 THz bandwidth for SHG.

Bandwidth tunable from 2.70 μm to 1.44 μm by changing film thickness.

Enabled on-chip quantum photonics with reconfigurable quasi-phase matching.

Abstract

Future quantum information networks operated on telecom channels require qubit transfer between different wavelengths while preserving quantum coherence and entanglement. Qubit transfer is a nonlinear optical process, but currently the types of atoms used for quantum information processing and storage are limited by the narrow bandwidth of up-conversion available. Here we present the first experimental demonstration of broadband and high-efficiency quasi-phase matching second harmonic generation (SHG) in a chip-scale periodically poled lithium niobate thin film. We achieve large bandwidth of up to 2 THz for SHG by satisfying quasi-phase matching and group-velocity matching simultaneously. Furthermore, by changing film thickness, the central wavelength of quasi-phase matching SHG bandwidth can be modulated from 2.70 um to 1.44 um. The reconfigurable quasi-phase matching lithium niobate thin film provides a significant on-chip integrated platform for photonics and quantum optics.