# Nonlinear filtering of an optical pulse train using dissipative Kerr solitons

## TL;DR

This paper demonstrates nonlinear filtering of optical pulse trains using dissipative Kerr solitons in microresonators, enabling longer information storage and narrower filter widths than traditional cavity linewidths, with applications in metrology and photonics.

## Contribution

It introduces a novel nonlinear filtering technique based on dissipative Kerr solitons, surpassing the limitations of cavity linewidths for optical filtering.

## Key findings

- Filter width can be more than ten times narrower than the cavity's intrinsic linewidth.
- Soliton dynamics enable longer information storage than the cavity's energy storage time.
- Experimental results align with analytical and numerical models.

## Abstract

The capability to store light for extended periods of time enables optical cavities to act as narrow-band optical filters, whose linewidth corresponds to the cavity's inverse energy storage time. Here, we report on nonlinear filtering of an optical pulse train based on temporal dissipative Kerr solitons in microresonators. Our experimental results in combination with analytical and numerical modelling show that soliton dynamics enables storing information about the system's physical state longer than the cavity's energy storage time, thereby giving rise to a filter width that can be more than an order of magnitude below the cavity's intrinsic linewidth. Such nonlinear optical filtering can find immediate applications in optical metrology, low-timing jitter ultra-short optical pulse generation and potentially opens new avenues for microwave photonics.