Ultra-broadband 3-dB coupler based on dual-hollow-core polymer fiber covering E plus S plus C plus L plus U band

Authors：Jia, Haoqiang; Lou, Shuqin; Hou, Donglian; Xue, Lu; Sheng, Inzhi; Chu, Paul K.; Wang, Xin^*

Source：Optics Express, 2023, 31(18): 29877-29886.

DOI：10.1364/OE.494281

• DESIGN

An ultra-broadband 3-dB coupler based on a polymer dual-hollow-core anti-resonant fiber (DHC-ARF) is designed to work in the E + S + C + L + U communication band. By incorporating two elliptical-like cores and modulating the air gap between the two cores, the wavelength and polarization dependence of the DHC-ARF-based coupler is reduced effectively. The feasibility of using a 1.46 cm long DHC-ARF as the ultra-broadband coupler for the operating bandwidth of 400 nm in the range between 1.33 & mu;m and 1.73 & mu;m is demonstrated theoretically. The coupling ratio of each polarized mode stabilizes at 50 & PLUSMN; 2% and the coupling ratio difference between the two polarized modes changes within & PLUSMN;0.6%. This DHC-ARF coupler which is made of a polymer can be fabricated by high-resolution 3D printing. Compared to a silica-based DHC-ARF coupler, the polymer-based DHC-ARF coupler is easier to manufacture and the total loss of the latter is only 0.041 & PLUSMN; 0.006 dB in the operating bandwidth. The polymer hollow-core fiber coupler boasting an ultra-broadband, short component length, and low loss is very promising in next-generation, high-speed, and large-capacity hollow-core fiber communication systems.

• Institution
  北京交通大学