Design and Characteristic Study of Terahertz Photonic Crystal Fiber for Orbital Angular Momentum Modes

In this paper, we design a new type of terahertz orbital angular momentum (OAM) optical fiber with excellent transmission characteristics over a wide frequency range. Within the 0.8–1.8 THz frequency band, it shows stable support for transmission of the fifth-order OAM mode. Its dispersion control effect is excellent; it maintains the confinement loss of most modes at the extremely low level of 10−10 dB/m; its maximum dispersion is only 5.57 ps/THz/cm; and its effective mode field area is greater than 1.11 × 10−7 m2. These characteristics jointly endow this optical fiber with broad application prospects and significant research value in the field of terahertz communication. With the continuous advancement of technology in this field, this optical fiber is expected to become a key component when building efficient, reliable, and large-capacity communication systems.