Details

Autor(en) / Beteiligte

• Wang, Zhuo
• Tu, Jiajing
• Liu, Zhengyong
• Yu, Changyuan
• Lu, Chao

Titel

Design of Weakly Coupled Two-Mode Hollow-Core Antiresonant Fiber With Low Loss

Ist Teil von

• Journal of lightwave technology, 2020-02, Vol.38 (4), p.864-874

Ort / Verlag

New York: IEEE

Erscheinungsjahr

2020

Quelle

IEEE/IET Electronic Library (IEL)

Beschreibungen/Notizen

• We first design and optimize a hollow-core conjoined-tube antiresonant fiber (CT-ARF) for weakly coupled <inline-formula><tex-math notation="LaTeX">\mathrm{LP_{01}}</tex-math></inline-formula> and <inline-formula><tex-math notation="LaTeX">\mathrm{LP_{11}}</tex-math></inline-formula> modes transmission. The critical core radii for the weak-coupling condition in the CT-ARFs with 4 to 8 tubes are obtained. Using numerical simulation, we demonstrate that by tuning the glass sheets positions in cladding tubes the confinement losses (CLs) of higher-order modes (HOMs) <inline-formula><tex-math notation="LaTeX">\mathrm{LP_{21}}</tex-math></inline-formula>, <inline-formula><tex-math notation="LaTeX">\mathrm{LP_{02}}</tex-math></inline-formula>, and <inline-formula><tex-math notation="LaTeX">\mathrm{LP_{31}}</tex-math></inline-formula> can be maximized through core-cladding mode coupling. Among the CT-ARFs with 4 to 8 tubes, the 6-tube one is proved to have the lowest CLs and bending losses of <inline-formula><tex-math notation="LaTeX">\mathrm{LP}_{01}</tex-math></inline-formula> and <inline-formula><tex-math notation="LaTeX">\mathrm{LP}_{11}</tex-math></inline-formula> modes and the highest CL ratios between the undesired HOMs and the two guided modes. In the designed 6-tube CT-ARF, <inline-formula><tex-math notation="LaTeX">\mathrm{LP_{01}}</tex-math></inline-formula> and <inline-formula><tex-math notation="LaTeX">\mathrm{LP_{11}}</tex-math></inline-formula> modes have low CLs in the transmission band of 1.31-1.65 <inline-formula><tex-math notation="LaTeX">\mu \text{m}</tex-math></inline-formula>. The minimum CLs of <inline-formula><tex-math notation="LaTeX">\mathrm{LP_{01}}</tex-math></inline-formula> and <inline-formula><tex-math notation="LaTeX">\mathrm{LP_{11}}</tex-math></inline-formula> modes are <inline-formula><tex-math notation="LaTeX">\text{1.7}\times \text{10}^{-4} \text{ dB/m}</tex-math></inline-formula> and <inline-formula><tex-math notation="LaTeX">\text{3.1} \times \text{10}^{-3} \text{ dB/m}</tex-math></inline-formula> in the C-band (1.53-1.565 <inline-formula><tex-math notation="LaTeX">\mu \text{m}</tex-math></inline-formula>) respectively. A 10 cm bend has a weak influence on the two guided modes. The CL ratio between the lowest loss HOM and <inline-formula><tex-math notation="LaTeX">\mathrm{LP}_{11}</tex-math></inline-formula> mode keeps <inline-formula><tex-math notation="LaTeX">>\!\!150</tex-math></inline-formula> in the wavelength range from 1.25-1.65 <inline-formula><tex-math notation="LaTeX">\mu \text{m}</tex-math></inline-formula>, which ensures the high purity of <inline-formula><tex-math notation="LaTeX">\mathrm{LP_{01}}</tex-math></inline-formula> and <inline-formula><tex-math notation="LaTeX">\mathrm{LP}_{11}</tex-math></inline-formula> modes. The fabrication tolerances of the fiber are discussed.