Integrated resonant electro-optic comb enabled by platform-agnostic laser integration

TL;DR

This paper introduces a universal laser integration method compatible with various photonic platforms, enabling the creation of integrated electro-optic combs with broad applications in photonics and sensing.

Contribution

A novel platform-agnostic laser integration technique using micro-transfer printing that achieves consistent performance across diverse materials without platform-specific modifications.

Findings

Achieved nearly identical laser performance on lithium niobate and silicon nitride platforms.

Demonstrated integration of a laser with a resonant electro-optic comb generator producing over 80 comb lines.

Validated the method's versatility for applications in microwave photonics, spectroscopy, and Lidar.

Abstract

The field of integrated photonics has significantly impacted numerous fields including communication, sensing, and quantum physics owing to the efficiency, speed, and compactness of its devices. However, the reliance on off-chip bulk lasers compromises the compact nature of these systems. While silicon photonics and III-V platforms have established integrated laser technologies, emerging demands for ultra-low optical loss, wider bandgaps, and optical nonlinearities necessitate other platforms. Developing integrated lasers on less mature platforms is arduous and costly due to limited throughput or unconventional process requirements. In response, we propose a novel platform-agnostic laser integration technique utilizing a singular design and process flow, applicable without modification to a diverse range of platforms. Leveraging a two-step micro-transfer printing method, we achieve nearly identical laser performance across platforms with refractive indices between 1.7 and 2.5. Experimental validation demonstrates strikingly similar laser characteristics between devices processed on lithium niobate and silicon nitride platforms. Furthermore, we showcase the integration of a laser with a resonant electro-optic comb generator on the thin-film lithium niobate platform, producing over 80 comb lines spanning 12 nm. This versatile technique transcends platform-specific limitations, facilitating applications like microwave photonics, handheld spectrometers, and cost-effective Lidar systems, across multiple platforms.