Fig. 1. Schematic diagram of the CT slip ring, which utilizes the conversion between optical and electrical signals to achieve data signal propagation.

Fig. 2. Structure diagram of FSEC system (LD: laser diode).

Fig. 3. Structure diagram of fiber side-emitting system applied to CT communication slip rings.

Fig. 4. SEF model diagram (I_t: intensity at the incoming end of the fiber; I_i: incident intensity; I_o: outgoing intensity; I_s: scattered intensity; Δx: fiber side emitting length).

Fig. 5. Model diagram of side light irradiance at (r, x₀) with an angle of (ζ, η) (e_x: the unit vector along the fiber x-axis; ρ: the radial coordinate in the plane perpendicular to the fiber axis; X_S: the coordinate along the fiber’s central x-axis at which side emission occurs; r: the radial distance from the fiber axis; x₀: the position along the x-axis; (ζ, η): the coordinate that describes the direction of the side emitted light).

Fig. 6. Attenuation of different diameters of SI-POF (SI-POF: step-index plastic optical fiber) by the POF-AC (POF Application Center, Germany).

Fig. 7. Side light direct coupling into the detector structure diagram. (a) Layout structure diagram. (b) Ray trace result diagram.

Fig. 8. Structure diagram of parabolic mirror and cylindrical lens system. (a) Layout structure diagram. (b) Ray trace results.

Fig. 9. FSEC system, where BERT is a bit error rate tester, LD is a laser diode, APD is an avalanche photodiode, and CDR is a clock and data recovery.

Fig. 10. FSEC system experiment, where BERT is bit error rate tester, LD Module is a laser diode driver module, Receiver is a photodetector module, and the CDR is a clock and data recovery. (a) Overall experimental setup diagram; (b) top view.

Fig. 11. System communication rate experiment. (a) Experimental results of BER. (b) 1.25 Gbps eye diagrams for data rates. The test environment employed a BSRT that generated a pseudo-random bit sequence as the transmitted signal.

Fig. 12. Received optical power and BER versus distance in the FSEC system experiments.

Fig. 13. Irradiance E as a function of the position x along the fiber for the example of a fiber segment.