A photonic integrated circuit based erbium-doped amplifier

TL;DR

This paper demonstrates a high-power, integrated erbium-doped amplifier on a silicon nitride photonic chip, enabling significant advancements in integrated optical amplification and applications.

Contribution

It introduces a novel erbium-doped amplifier on a photonic integrated circuit with high output power and gain, surpassing previous integrated solutions.

Findings

Achieved 145 mW output power and over 30 dB gain.

Enabled 100-fold increase in soliton microcomb power.

Matched performance of commercial fiber amplifiers.

Abstract

Erbium-doped fiber amplifiers have revolutionized long-haul optical communications and laser technology. Erbium ions could equally provide a basis for efficient optical amplification in photonic integrated circuits. However, this approach has thus far remained impractical due to insufficient output power. Here, we demonstrate a photonic integrated circuit based erbium amplifier reaching 145 mW output power and more than 30 dB small-signal gain -- on par with commercial fiber amplifiers and beyond state-of-the-art III-V heterogeneously integrated semiconductor amplifiers. We achieve this by applying ion implantation to recently emerged ultralow-loss Si3N4 photonic integrated circuits with meter-scale-length waveguides. We utilize the device to increase by 100-fold the output power of soliton microcombs, required for low-noise photonic microwave generation or as a source for wavelength-division multiplexed optical communications. Endowing Si3N4 photonic integrated circuits with gain enables the miniaturization of a wide range of fiber-based devices such as high-pulse-energy femtosecond mode-locked lasers.