Coherent satellites in multispectral regenerative frequency microcombs

Jinghui Yang,Chee Wei Wong,Shu-Wei Huang,Dim-Lee Kwong,Zhenda Xie,Mingbin Yu

doi:10.1038/s42005-019-0274-x

Abstract

Multispectral frequency combs provide new architectures for laser spectroscopy, clockwork, and high-capacity communications. Frequency microcombs have demonstrated remarkable impact in frequency metrology and synthesis, albeit with spectral bandwidth bounded by intrinsic second-order dispersion and consequently low-intensities at the spectral edges. Here we report coherent satellite clusters in multispectral regenerative frequency microcombs with enhanced intensities at the octave points and engineered frequency span. Beyond the conventional bandwidth of parametric oscillation, the regenerative satellites are facilitated by higher-order dispersion control, allowing for multiphase-matched parametric processes. The satellite span is deterministically controlled from 34 to 72 THz by pumped at C/L-bands, with coherence preserved with the central comb through the nonlinear parametric process. We further show the mirrored appearance of the satellite transition dynamics simultaneously with the central comb at each comb state. These multispectral satellites extend the scope of parametric-based frequency combs and provide a unique platform for clockwork, spectroscopy and communications.

Highlights

Multispectral frequency combs provide new architectures for laser spectroscopy, clockwork, and high-capacity communications
Optical parametric processes serve as the fundamental mechanism for a variety of nonlinear optics phenomena and unique applications involving laser frequency combs[1,2,3], squeezed state generation[4,5], four-wave mixing with matter waves[6], high-harmonic generation[7], and Bose−Einstein condensation[8]
In a parametric-based frequency microcomb, an overall comb bandwidth of an octave or two-third of an octave will allow for a self-referenced frequency stabilization through fto-2f or 2f-to-3f carrier-envelope-offset technique[9,10], which enables the precise definition of the comb line frequency without requiring an external optical reference

Summary

Introduction

Multispectral frequency combs provide new architectures for laser spectroscopy, clockwork, and high-capacity communications. This has led to the successful implementation of 2f-3f self-referencing assisted by external laser sources[10] This approach, still suffers from low comb powers at the octave points for harmonic (2f or 3f) generations and usually requires high-power transfer lasers to overcome the hyperbolic-secant intensity falloff bottleneck of frequency comb[16]. The primarily phase-matched modes, spectrally determined by the local anomalous dispersion, nonlinear frequency shift and pump-resonance detuning, will shape the total bandwidth and general envelope of the overall comb spectrum These primary modes and their subcombs are predominantly bounded by the second-order dispersion, striving for a near-zero or normal second-order dispersion for broadband clusters[32,33] and multioctave parametric oscillation[34]. The multiphase-matched regenerative satellite combs can serve as promising platforms for ultrabroadband coherent communications, self-referenced frequency combs, and multispectral precision sensing and spectroscopy

Methods

Results

Conclusion