Full analysis of a high-bandwidth microring-based PIN modulator

This study presents a new simulation strategy for a high-speed microring-based PIN modulator using the finite element method. It includes dc and transient simulations of the electro-optical behavior of the device. Variations in the effective refractive index and their effect on the optical output fields are determined by applying a reverse bias voltage pulse to the device. The frequency responses have been calculated for the microring modulator and 3 dB bandwidth. Calculations show a 3 dB bandwidth of over 115 GHz for a ring with a radius of 8 µm and a width of 0.5 µm at -7 V biasing voltage

Second harmonic generation using an electrically controlled asymmetric plasmonic waveguide

In this study, it was shown that field enhancement in the nonlinear metal-insulator-metal (MIM) plasmonic waveguides can result in a large enhancement of the second harmonic generation (SHG) magnitude as compared with values reported in the literature. The proposed structure has two metals at the top and two metals at the bottom of the crystal. In this structure, a voltage is applied on metals to produce a SHG electrically. Hence, the metals that define the cavity also serve as electrodes capable of generating high direct current electric fields across the nonlinear material. The frequency of a fundamental wave at 458 nm was doubled and modulated in intensity by applying a moderate external voltage to the electrodes, yielding a voltage-dependent nonlinear generation with a higher coupling efficiency. All the simulations here have been calculated by using the finite-element-based commercial COMSOL software

Plasmonic thin film InP/graphene-based Schottky-junction solar cell using nanorods

Herein, the design and simulation of graphene/InP thin film solar cells with a novel periodic array of nanorods and plasmonic back-reflectors of the nano-semi sphere was proposed. In this structure, a single-layer of the graphene sheet was placed on the vertical nanorods of InP to form a Schottky junction. The electromagnetic field was determined using solving three-dimensional Maxwell's equations discretized by the finite difference method (FDM). The enhancement of light trapping in the absorbing layer was illustrated, thereby increasing the short circuit current to a maximum value of 31.57 mA/cm2 with nanorods having a radius of 400 nm, height of 1250 nm, and nano-semi sphere radius of 50 nm, under a solar irradiation of AM1.5G. The maximum ultimate efficiency was determined to be 45.8% for an angle of incidence of 60°. This structure has shown a very good light trapping ability when graphene and ITO layers were used at the top and as a back-reflector in the proposed photonic crystal structure of the InP nanorods. Thence, this structure improves the short-circuit current density and the ultimate efficiency of 12% and 2.7%, respectively, in comparison with the InP-nanowire solar cells

Full analysis of a high-bandwidth microring-based PIN modulator

198-202This study presents a new simulation strategy for a high-speed microring-based PIN modulator using the finite element method. It includes dc and transient simulations of the electro-optical behavior of the device. Variations in the effective refractive index and their effect on the optical output fields are determined by applying a reverse bias voltage pulse to the device. The frequency responses have been calculated for the microring modulator and 3 dB bandwidth. Calculations show a 3 dB bandwidth of over 115 GHz for a ring with a radius of 8 µm and a width of 0.5 µm at -7 V biasing voltage

InP-based ridge lasers with lateral n-contacts

High-speed devices such as modulators and photodetectors on InP require the use of a semi-insulating substrate. Monolithically integrated lasers on semi-insulating substrates have to be provided with lateral n-contacts for current injection. In order to compare the performance of lateral n-contact with conventional back-side n-contacts, we fabricated ridge lasers on n-substrate that were provided with both lateral and backside n-contacts. In this article the performance of both types of contacts is compared