An electrical absorption graphene modulator based on hybrid plasmonic waveguide is theoretically demonstrated. The sidewall scattering loss is mostly restrained by the vertical metal-insulator-silicon (MIS) waveguide structure. The patterned Si ₃ N ₄ (SiN) can both serve as the mask and the insulation layer, which offers the direct formation of silicon stripe by thermal oxidization. The metal cap layer utilized as an electrode is favorable to improve the frequency response. By finite element method (FEM) optimization of waveguide dimensions, the 700 nm-wide optical 3 dB-bandwidth that ranges from 1200 to 1900 nm can be obtained at the modulation length of 30 μm. The propagation loss is reduced to 0.088 dB/μm. The modulation depth and power consumption are calculated to be 0.509 dB/μm and 61.3 fJ/bit, respectively. The estimated electrical 3 dB-bandwidth of 330 GHz promises the proposed modulator potentials in next generation on-chip optical signal processing.

A broadband polarization-insensitive graphene modulator has been proposed. The dual built-in orthogonal slots waveguide allows polarization independence for the transverse electric (TE) mode and the transverse magnetic (TM) mode. Due to the introduction of metal slots in both the vertical and horizontal directions, the optical field as well as the electro-absorption of graphene are enhanced by the plasmonic effect. The proposed electro-optic modulator shows a modulation depth of 0.474 and 0.462 dB/μm for two supported modes, respectively. An ultra-low effective index difference of 0.001 can be achieved within the wavelength range from 1100 to 1900 nm. The 3 dB-bandwidth is estimated to be 101 GHz. The power consumption is 271 fJ/bit at a modulation length of 20 μm. The proposed modulator provides high speed broadband solutions in microwave photonic systems.

The growth interruption technology is introduced to the growth of GaAsP/InAlGaAs quantum well (QW) structure using metal–organic chemical vapor deposition (MOCVD). The effect of growth interruption time (GIT) on the crystalline quality and optical properties are investigated. The two distinctive emission peaks are the transition recombination between the electron level of conduction band and the light and heavy hole level of valence band in the photoluminescence (PL) at room temperature. The PL peaks present a redshift and merge together with the increasing GIT, which is attributed to the QW energy level shift caused by the increase in arsenic concentrations in GaAsP QW, the diversified thickness of QW and the variations of indium components in the InAlGaAs barrier layer. The Gaussian deconvolution parameters in temperature-dependent PL (TDPL) show that the GaAsP/InAlGaAs QW with a GIT of 6 s has a 565.74 meV activation energy, enhancing the carrier confinement in QW and the PL intensity, while the 6 s-GIT GaAsP QW has the increasing interface roughness and the non-radiative centers at the InGaAsP intermediate layer, leading to a spectral broadening. The QW with 10 s-GIT exhibits a small full width at half maximum (FWHM) with the various temperature, indicating reduced interface roughness and excellent crystal quality. An increase in GIT may be suitable for optimizing the optical properties of GaAsP/InAlGaAs QW.

Magneto-optical (MO) nonreciprocal devices are essential for integrated photonics and thermal-radiation control, yet a scalable III–V semiconductor platform with strong tunability remains lacking. Here, we report high-quality Si-doped InAs films grown on GaAs (100) via a tailored three-step metal-organic chemical vapor deposition (MOCVD) process. Systematic optical and electrical measurements reveal the quantitative link between carrier modulation and nonreciprocal optical response. Electron concentrations ( N ) tunable from 10 ¹⁸ to 4.7 × 10 ¹⁹ cm ⁻³ with a mobility ( μ ) of 1500 cm ² ·V ⁻¹ ·s ⁻¹ at the highest doping level are achieved. We designed MO nonreciprocal structures that exploit epsilon-near-zero (ENZ) engineering and doping-gradient effects. Simulations based on experimentally extracted parameters predict broadband, direction-dependent absorption and emission in the 10–13 µm band, with nonreciprocity exceeding 60%. These findings establish MOCVD-grown InAs/GaAs as a practical and tunable III–V semiconductor platform for integrated nonreciprocal photonics and mid-infrared energy-management devices.