# Packaged photonic chip-based soliton microcomb using an ultralow-noise laser

## TL;DR

This paper demonstrates a compact, chip-based soliton microcomb driven by an ultra-low-noise laser, enabling easy access to single soliton states without complex tuning mechanisms, suitable for field applications.

## Contribution

It introduces a current-initiated, Si3N4 chip-based soliton microcomb driven by a low-noise laser, simplifying the generation of single soliton states without fast tuning.

## Key findings

- Achieved 99-GHz soliton microcomb with a low-noise laser.
- Developed a reliable packaging technique for field deployment.
- Demonstrated easy access to single soliton states via laser current adjustment.

## Abstract

Photonic chip-based soliton microcombs have shown rapid progress and have already been used in many system-level applications, including coherent communications, astrophysical spectrometer calibration and ultrafast ranging. While there has been substantial progress in realizing soliton microcombs that rely on compact laser diodes, culminating in devices that only utilize a semiconductor amplifier or a self-injection-locked laser as a pump source, accessing and generating single soliton states with electronically detectable line rates from a compact laser module has remained challenging. Here we demonstrate a current-initiated, $\mathrm{Si_3N_4}$ chip-based, 99-GHz soliton microcomb driven directly by an ultra-compact, low-noise laser. This approach does not require any fast laser tuning mechanism, and single soliton states can be accessed by changing the current of the laser diode. A simple, yet reliable, packaging technique has been developed to demonstrate the viability of such a microcomb system in field-deployable applications.