Low loss and polarization-insensitive coupling length for a terahertz fiber directional coupler with symmetric dual-suspended core structure

Citation

Zhu, Y.-F., Huang, X., Ke, Q., Liu, G., Rao, C.-F., Kong, D., Mei, P., Liu, Y., & Wang, H. (2021). Low loss and polarization-insensitive coupling length for a terahertz fiber directional coupler with symmetric dual-suspended core structure. Optics Communications, 480, 126497. https://doi.org/10.1016/j.optcom.2020.126497

Keywords

• Birefringence
• Coupling length
• Fiber coupler
• Transmission loss

Brief

The paper proposes and numerically investigates a novel dual-suspended core terahertz (THz) fiber directional coupler designed to achieve low loss and a polarization-insensitive coupling length by optimizing its geometric parameters.

Summary

This paper proposes and numerically investigates a novel dual-suspended core terahertz (THz) fiber directional coupler. The design aims to address the challenges of high loss and polarization-sensitive coupling lengths in existing THz fiber devices. By optimizing the geometric parameters of the fiber structure, numerical simulations show that the proposed coupler can achieve low transmission loss (partially by distributing THz wave power in air) and a short, polarization-insensitive coupling length. For instance, at a frequency of 1.00 THz, a coupling length of just 0.421 cm can be achieved with low transmission losses of approximately 0.30 dB and 0.26 dB for x- and y-polarization, respectively. The study suggests this design is a promising solution for developing high-performance THz devices.

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