Higher-Order Mode Suppression in Antiresonant Nodeless Hollow-Core Fibers

Micromachines

卷:10

Fanchao Meng¹  Yanfeng Li¹  Minglie Hu¹  Aichen Ge¹  Bowen Liu¹ 

[1] Ultrafast Laser Laboratory, School of Precision Instrument and Optoelectronics Engineering, Key Laboratory of Optoelectronic Information Technology (Ministry of Education), Tianjin University, Tianjin 300072, China;

关键词: hollow-core fiber;    antiresonant fiber;    negative curvature fiber;   

DOI  :  10.3390/mi10020128

来源: DOAJ

【 摘 要 】

Negative curvature hollow-core fibers (NC-HCFs) are useful as gas sensors. We numerically analyze the single-mode performance of NC-HCFs. Both single-ring NC-HCFs and nested antiresonant fibers (NANFs) are investigated. When the size of the cladding tubes is properly designed, higher-order modes (HOMs) in the fiber core can be coupled with the cladding modes effectively and form high-loss supermodes. For the single-ring structure, we propose a novel NC-HCF with hybrid cladding tubes to enable suppression of the first two HOMs in the core simultaneously. For the nested structure, we find that cascaded coupling is necessary to maximize the loss of the HOMs in NANFs, and, as a result, NANFs with five nested tubes have an advantage in single-mode guidance performance. Moreover, a novel NANF with hybrid extended cladding tubes is proposed. In this kind of NANF, higher-order mode extinction ratios (HOMERs) of 10⁵ and even 10⁶ are obtained for the LP₁₁ and LP₂₁ modes, respectively, and a similar level of 10⁵ for the LP₀₂ modes. Good single-mode performance is maintained within a broad wavelength range. In addition, the loss of the LP₀₁ modes in this kind of NANF is as low as 3.90 × 10⁻⁴ dB/m.

【 授权许可】

Unknown