Fig. 1. EO polymer modulator. (a) Schematic of the thin-film SOH EO modulator. The inset is TE₀ mode distribution. (b) Molecular structures of chromophore AJLZ53 and host polymer amorphous polycarbonate. (c) The field interaction factor as a function of waveguide width. (d) The absorption loss of the thin-film waveguide as a function of the gap among the metal electrode, the waveguide core, and the waveguide width.

Fig. 2. Fabrication of EO polymer modulator. (a) Fabrication process of the thin-film SOH EO modulator. (b) Poling curve of the modulator. The black, red, and blue lines represent poling voltage, leakage current, and poling temperature, respectively. (c) SEM image of the thin-film waveguide.

Fig. 3. (a) Testing setup for the EO frequency response of the modulator, including electrical connections (red) and optical paths (black) using single-mode fibers. PC, polarization controller; EDFA, erbium-doped fiber amplifier; BPF, bandpass filter; PD, photodetector. (b) Transmission spectra of the device before and after poling. (c) Transmission spectra of thin-film SOH EO modulator under different DC voltages. (d) Wavelength shifts in relation to the applied voltage. (e) Measured EO transmission S₂₁ for devices (1 mm).

Fig. 4. Variations in EO response within the device over time.