Ring-Core Photonic Crystal Fiber of Terahertz Orbital Angular Momentum Modes with Excellence Guiding Properties in Optical Fiber Communication

• DOI: 10.3390/photonics8040122
• Publication Date: 2021-04-14T08:21:08Z
• Authors: Fahad Ahmed Al-Za...; Md. Anowar Kabir
• Keywords: 0202 electrical engineering, electronic engineering, information engineering; orbital angular momentum (OAM); ring-core photonic crystal fiber (RC-PCF); Applied optics. Photonics; terahertz (THz); mode division multiplexing (MDM); 02 engineering and technology; space division multiplexing (SDM); optical communication; mode separation; TA1501-1820

The orbital angular momentum (OAM) of light is used for increasing the optical communication capacity in the mode division multiplexing (MDM) technique. A novel and simple structure of ring-core photonic crystal fiber (RC-PCF) is proposed in this paper. The ring core is doped by the Schott sulfur difluoride material and the cladding region is composed of fused silica with one layer of well-patterned air-holes. The guiding of Terahertz (THz) OAM beams with 58 OAM modes over 0.70 THz (0.20 THz–0.90 THz) frequency is supported by this proposed RC-PCF. The OAM modes are well-separated for their large refractive index difference above 10−4. The dispersion profile of each mode is varied in the range of 0.23–7.77 ps/THz/cm. The ultra-low confinement loss around 10−9 dB/cm and better mode purity up to 0.932 is achieved by this RC-PCF. For these good properties, the proposed fiber is a promising candidate to be applied in the THz OAM transmission systems with high feasibility and high capacity.