Multi-octave two-color soliton frequency comb in integrated chalcogenide microresonators

Huanjie Cheng; Guosheng Lin; Di Xia; Liyang Luo; Siqi Lu; Changyuan Yu; Bin Zhang

doi:10.1007/s12200-024-00139-x

Multi-octave two-color soliton frequency comb in integrated chalcogenide microresonators

Front Optoelectron. 2024 Nov 11;17(1):36. doi: 10.1007/s12200-024-00139-x.

Authors

Huanjie Cheng^#¹, Guosheng Lin^#¹, Di Xia^#¹, Liyang Luo¹, Siqi Lu¹, Changyuan Yu², Bin Zhang³

Affiliations

¹ Guangdong Provincial Key Laboratory of Optoelectronic Information Processing Chips and Systems, School of Electrical and Information Technology, Sun Yat-sen University, Guangzhou, 510275, China.
² Photonics Research Center, Department of Electronic and Information Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong, China.
³ Guangdong Provincial Key Laboratory of Optoelectronic Information Processing Chips and Systems, School of Electrical and Information Technology, Sun Yat-sen University, Guangzhou, 510275, China. zhangbin5@mail.sysu.edu.cn.

^# Contributed equally.

Abstract

Mid-infrared (MIR) Kerr microcombs are of significant interest for portable dual-comb spectroscopy and precision molecular sensing due to strong molecular vibrational absorption in the MIR band. However, achieving a compact, octave-spanning MIR Kerr microcomb remains a challenge due to the lack of suitable MIR photonic materials for the core and cladding of integrated devices and appropriate MIR continuous-wave (CW) pump lasers. Here, we propose a novel slot concentric dual-ring (SCDR) microresonator based on an integrated chalcogenide glass chip, which offers excellent transmission performance and flexible dispersion engineering in the MIR band. This device achieves both phase-matching and group velocity matching in two separated anomalous dispersion regions, enabling phase-locked, two-color solitons in the MIR region with a commercial 2-μm CW laser as the pump source. Moreover, the spectral locking of the two-color soliton enhances pump wavelength selectivity, providing precise control over soliton dynamics. By leveraging the dispersion characteristics of the SCDR microresonator, we have demonstrated a multi-octave-spanning, two-color soliton microcomb, covering a spectral range from 1156.07 to 5054.95 nm (200 THz) at a -40 dB level, highlighting the versatility and broad applicability of our approach. And the proposed multi-octave MIR frequency comb is relevant for applications such as dual-comb spectroscopy and trace-gas sensing.

Keywords: Chalcogenide glasses; Kerr microcombs; Mid-infrared; Multi-octave; Two-color soliton.