Fig. 1. Schematic diagram of the structure of the microstructured terahertz fiber model

Fig. 2. Simulation results of the complete terahertz fiber. (a) Effective refractive index variation of the fundamental mode in the range of 0.1-1.2 THz; (b) mode field diagram at 0.675 THz (outer layer is perfectly matched layer and air layer)

Fig. 3. Simulation results of side-polished terahertz fiber. (a) Confinement loss plots of terahertz fibers with different side throw depths; (b) mode field distribution of terahertz fibers with different side throw depths at 0.675 THz

Fig. 4. Simulation results of side-polished terahertz fiber after integrating GaAs. (a) GaAs/SPTF model schematic and mode field diagram; (b) device limiting loss under different GaAs conductivity when side-polished three-layer small air holes; (c) limiting loss difference variation under different GaAs conductivity when side-polished three-layer small air holes

Fig. 5. Diagrams of device preparation equipment. (a) Schematic diagram of the side-polished equipment; (b) photovoltaic device integration platform

Fig. 6. Modulation depth test system structure schematic

Fig. 7. Test results of side-polished fiber coated with UV adhesive under different power laser irradiation. (a) Time domain spectrum; (b) frequency domain spectrum

Fig. 8. GaAs/SPTF test results with a remaining thickness of 1.55 mm in the side throw. (a) Time domain spectrum at different laser powers; (b) frequency domain spectrum at different laser powers; (c) modulation depth spectrum at different laser powers; (d) correspondence between modulation depth and laser power at 0.55 THz

Fig. 9. GaAs/SPTF test results with a remaining thickness of 1.80 mm in the side throw. (a) Time domain spectrum at different laser powers; (b) frequency domain spectrum at different laser powers; (c) modulation depth spectrum at different laser powers; (d) correspondence between modulation depth and laser power at 0.61 THz

Fig. 10. GaAs/SPTF test results with a remaining thickness of 2.05 mm in the side throw. (a) Time domain spectrum at different laser powers; (b) frequency domain spectrum at different laser powers; (c) modulation depth spectrum at different laser powers; (d) correspondence between modulation depth and laser power at 0.82 THz

Fig. 11. Comparison of modulation effects between the new type of optically controlled GaAs/SFPT modulator and other optically controlled terahertz modulators

Table 1. Modulation effect of the side-polished terahertz fiber modulator under 808 nm laser action