The family of III-V semiconductors is of high significance in photonics for two main reasons. First, not only they are the most practical material platforms for active photonic devices but also they are suitable for monolithic integration of passive and active photonic devices. Second, some III-V compounds exhibit high values of second and third-order nonlinear coefficients – the property useful in all-optical signal processing and wavelength conversion. This Ph.D. thesis explores the above perspectives with two candidates from the group III-V family, namely AlGaAs and InGaAsP. The dissertation consists of two main parts. The first part is dedicated to the theoretical modelling of nonlinear bianisotropic AlGaAs metasurfaces, while the second part focuses on the experimental studies of the nonlinear optical performance of InGaAsP waveguides. Concerning the first part, due to the high confinement of light supported by the Mie resonances, AlGaAs nanoantennas and metasurfaces with both high refractive index and high nonlinear susceptibility have found a unique place in planar nonlinear optics, where not only the presence of high intensity of light is of significant matter, but also the optically thin thickness of the entities releases the device from phase matching. We first describe the linear optical properties of AlGaAs meta-atoms and metasurfaces such as relatively high scattering cross-sections and the bianisotropic effect. Also, we derive and explain all required analytic formulas for this purpose. Bianisotropic metasurfaces with magnetoelectric coupling and asymmetric optical properties have sparked considerable interest in linear meta-optics. However, further in this thesis, we explore the nonlinear features of bianisotropic AlGaAs metasurfaces. In particular, we explore a second-harmonic generation in a bianisotropic AlGaAs metasurface based on the multipolar interference inside the meta-atoms and the nonlinear polarization current. We theoretically demonstrate that it is possible to obtain several orders of magnitude secondharmonic power differences for the forward and backward illuminations by adjusting the geometrical parameters of the meta-atoms in such a way that quasi-bound states in the continuum (quasi-BICs) are achievable. This research paves the way for the generation of directional higher-order waves. Concerning the second part, the research is focused on exploring nonlinear material platforms for monolithic integration of active and passive devices on the same chip. In this regard, we explore InGaAsP/InP waveguides of different geometries. First, we provide the theoretical background such as the nonlinear Schrodinger equation and four-wave mixing (FWM) equations in a nonlinear waveguide, then we solve the set of FWM equations using MATLAB to observe the qualitative behavior of the signal, idler, and the pump inside a nonlinear waveguide. Furthermore, we design and employ two waveguide geometries i.e. half-core and nanowire waveguides. We first design these waveguides so that achieving zero group velocity dispersion is possible through a suitable material composition and certain geometrical dimensions. However, for the rest of the work, we continued with the waveguides of different dimensions compared to the designed ones (due to some limitations in fabrication). We demonstrate self-phase modulation (SPM) and FWM for the half-core waveguides. For the case of the nanowire waveguides, we also demonstrate the FWM effect. We measured and extracted the effective value of the nonlinear refractive index of InGaAsP/InP waveguides to be n2 = 1.9 × 10−13 cm2/W through the relation between the idler and the pump power when the phase mismatch is negligible. Finally, we experimentally observe the two-photon absorption effect in our waveguides through the nonlinear characteristics of input and output powers of the waveguides from which the two-photon absorption coefficient of 19 cm/GW is calculated.

Yes / In this paper, we present an analytical study for the investigation of the effects of the magnetoelectric elements of a reciprocal and nonreciprocal bianisotropic grounded substrate on the input impedance, resonant length of a dipole antenna as well as on the mutual coupling between two element printed dipole array in three configuration geometries: broadside, collinear and echelon printed on the same material. This study examines also the effect of the considered bianisotropic medium on the electric and magnetic field distributions that has been less addressed in the literature for antenna structures. Computations are based on the numerical resolution, using the spectral method of moments, of the integral equation developed through the mathematical derivation of the appropriate spectral Green’s functions of the studied dipole configuration. Original results, for chiral, achiral, Tellegen and general bi-anisotropic media, are obtained and discussed with the electric and magnetic field distributions for a better understanding and interpretation. These interesting results can serve as a stepping stone for further works to attract more attention to the reciprocal and non-reciprocal Tellgen media in-depth studies.