Experimental Demonstration of 5 Gbps Data Transmission Using Long Subwavelength Fiber at 140 GHz

We present the experimental demonstration of real-time data transmission using a long subwavelength dielectric fiber in the Terahertz (THz) frequency range. A commercial 3D printing filament made of polypropylene material with the diameter of 1.75 mm is used as the solid core fiber for signal transmission. A photonics-based THz communication system operating at the carrier frequency of 140 GHz is used to characterize the fiber. The fiber is butt coupled in both emitter and detector antenna to minimize the free space coupling loss. The performance of the fiber is measured by recording the bit error rate (BER) for the transmitted data rate of 5 Gbps with a pattern length of 2³¹-1. By fixing the decision threshold to 0 mV, the BER of 10^-7 is recorded for the fiber length of 3 m and 5 m respectively at the emitter photocurrent value of 8 mA. A successful error free data transmission using a 1 m fiber with the diameter of 670 μm is demonstrated. In addition, the effect of bending in a graded index porous fiber made of low density polyethylene is also studied.