Fig. 1. Permittivity as a function of electron concentration for four kinds of materials. (a) Real parts; (b) imaginary parts

Fig. 2. Silicon-based optical waveguide phase shifter. (a) Structure of proposed TCO-based optical waveguide phase shifter; (b) permittivity distribution of HfO2/TCO interface; (c) real and (d) imaginary parts of permittivity on gate voltage of cross-section cumulative layer of CdO film as functions of coordinate

Fig. 3. Device length L2π, absorption coefficient α, and insertion loss iloss, 2π of proposed TCO-based phase shifter as functions of gate voltage for achieving 2π-phase shift. (a)(b) Single-layer model; (c)(d) multi-layer model

Fig. 4. Performance comparative analysis of TCO-based phase shifters. Distributions of |E|2 of CdO-based phase shifter at gate voltages of (a) Vg= 0 V and (b) Vg= 1.4 V; distributions of (c) Hx and (d) Ey of TM mode at gate voltage of 1.4 V; distributions of electric-field component along central white dot line in Fig. 4(c) at different gate voltages for (e) SnO-based and (f) CdO-based waveguide phase shifters; (g) real and (h) imaginary parts of permittivity of accumulation layer TCOacc of waveguide ph

Fig. 5. Influences of device structural parameters on phase shifter performance. (a) CdO thickness; (b) width and height of silicon-based waveguide

Table 1. Optical performance parameters of four kinds of TCO materials

Table 2. Performance parameters of silicon-based waveguide phase shifters based on different TCO materials when generating 2π-phase shift