Widely Tunable Soliton Microcomb Chip

Introduction

The generation of optical frequency combs through nonlinear optical processes is an enabling technology for a wide range of applications. These combs, consisting of equally spaced coherent light frequencies, are highly valued in applications such as communications, LiDAR, and microwave photonics.

Development of Frequency Combs

The first generation of combs, developed using mode-locked lasers, expanded their spectrum through nonlinear media to create broadband frequency combs. Initially, these systems relied on bulky free-space optical components.

Microcomb Technology

Efforts to reduce the size, weight, and power (SWaP) of these systems led to the development of microcomb technology. Dissipative Kerr soliton (DKS) microcombs generated via nonlinear optical processes in microresonators have emerged as a more compact, scalable, chip-based alternative.

Advantages of DKS Microcombs

DKS microcombs offer several advantages, including:

• Higher repetition rates
• Lower power consumption
• Simplified broadband spectrum generation

These features have attracted significant market interest.

Challenges Faced by DKS Microcombs

Despite their advantages, DKS microcombs face several bottlenecks, including:

1. Limited tunability
2. Sensitivity
3. Poor conversion efficiency

ELASTIC Project Goals

The ELASTIC project aims to address these issues by leveraging the high thermo-optic coefficient and nonlinearity of the AlGaAsOI platform combined with a novel pump scheme.

Expected Outcomes

This approach will enable:

• Low-power
• Highly tunable
• Insensitive chip-scale comb systems

These systems are intended for emerging applications like:

• Massively parallel frequency-modulated continuous-wave LiDAR
• Wavelength-division multiplexing systems