Mid-Infrared Supercontinuum and Frequency Comb Generations by Different Optical Modes in a Multimode Chalcogenide Strip Waveguide

• Main Authors: Yujun Cheng, Jinhui Yuan, Chao Mei, Feng Li, Xian Zhou, Qiang Wu, Binbin Yan, Kuiru Wang, Chongxiu Yu, Keping Long, P. K. A. Wai
• Format: Article
• Language: English
• Published: IEEE 2020-01-01
• Series: IEEE Access
• Subjects: Chalcogenide strip waveguide; different optical modes; supercontinuum; frequency comb
• Online Access: https://ieeexplore.ieee.org/document/9248995/
• ISSN: 2169-3536

Supercontinuum (SC) with broad bandwidth and high coherence is crucial in the SC-based frequency comb source generation. In this paper, we numerically investigate the mid-infrared (MIR) SC generations with the three optical modes (TE₀₀, TE₁₀, and TE₂₀) in a multimode chalcogenide (As₂Se₃) strip waveguide. The waveguide structure is carefully engineered to ensure that the pump pulses are propagated in the normal dispersion regions of the considered three optical modes. Highly coherent and octave-spanning MIR SCs are generated when the optimized pump pulse with 80-fs pulse duration, 3-kW peak power, and 3-μm center wavelength is used. Moreover, the nonlinear dynamics of the SC generation are numerically analyzed. Finally, the SC-based frequency combs are numerically demonstrated when a pulse train with a repetition rate of 50 MHz is used as the pump source and launched into the multimode As₂Se₃-based strip waveguide. It is believed that the generated MIR SC and SC-based frequency comb sources have important applications in biophotonics, metrology, and sensing.