Simulation Of Photonic Devices Research Articles

Rigorous analysis of numerical methods: a comparative study

For any photonic device simulation, the accuracy of the numerical solution not only depends on the methods being used but also on the discretization parameters used in that numerical method. In this work, Finite Element Method and Finite Difference Time Domain Method based on Maxwell’s equations were used to simulate optical waveguides and directional couplers. As the solution accuracy may also depend on the index contrast used in such photonic devices, the characteristics of low-index contrast Germanium doped Silica and high-index contrast Silicon Nanowire Waveguides were analyzed, evaluated and benchmarked. Numerical results to benchmark Directional Couplers are also reported in this paper.

A Rigorous Circuit Model for Simulation of Large-Scale Photonic Integrated Circuits

A rigorous circuit model for the simulation of large-scale photonic integrated circuit (PIC) is proposed and validated. Different from the conventional circuit theory, both guided and radiation fields are taken into consideration in the circuit model. A PIC of arbitrary size and complexity is partitioned into a collection of basic circuit elements interconnected via physical and virtual ports. The model parameters describing the terminal properties of the circuit elements are extracted by numerical techniques for photonic device simulation such as FDTD method. The performance of the entire PIC can be simulated by conventional circuit simulation algorithms based on the complex scattering matrix formalism. In contrast with the existing numerical simulation techniques, the circuit model and the simulation methodology are more flexible, efficient, and scalable for the analysis of large-scale PICs.

Novel FEM Approach for the Analysis of Cylindrically Symmetric Photonic Devices

A novel scheme based on a 2-D finite element method (2-D-FEM) for the frequency domain, in cylindrical coordinates in conjunction with the perfectly matched layers (PML), is proposed and validated here. This scheme permits the analysis and simulation of photonic devices, including discontinuities along the propagation direction. Also, the present approach takes into account the dispersive nature of metals at optical wavelengths.

Modeling and simulation of photonic devices by generalized space mapping technique

The generalized space mapping (GSM) technique is employed for modeling and simulation of photonic devices. The mapping is established between the parameter spaces of coarse and fine models so that accuracy of the coarse model is significantly improved for a given range of parameters. To demonstrate the usefulness of this technique, modeling and simulation of an optical waveguide facet is used as an application example. Two methods are adopted for the coarse model, i.e., the transfer matrix method (TMM) and the free space radiation mode (FSRM) method. The time-intensive and accurate finite-difference time-domain (FDTD) method is used as the fine model for model calibration. The mapping-enhanced coarse models show significant improvement in terms of accuracy. Further, a criterion is established to measure the accuracy of the coarse models. It is shown that the FSRM is one order of magnitude more accurate than the TMM for the TE case, however, the two methods have almost the same level of accuracy for the TM case.

Multiple signal representation simulation of photonic devices, systems, and networks

Photonic systems design requires simulation over a wide range of scales; from wavelength-sized resonances in lasers and filters, to interactions in global networks. To design these global systems, while considering the effects of the smallest component, requires sophisticated simulation technology. We have developed the Photonic Transmission Design Suite, which includes five different signal representations, so that the details of device performance can be efficiently considered within a large network simulation. Alternatively, a design can be studied using a coarse signal representation before switching to a detailed representation for further refinement. We give examples of the application of these representations, and show how the representation of a signal is adapted as it propagates through a system to optimize simulation efficiency.

FDTD simulation of photonic devices and circuits based on circular and fan-shaped microdisks

This paper proposes novel photonic devices and circuits composed of circular and fan-shaped microdisks. Using the finite difference time domain (FDTD) method, we investigated propagation characteristics of light in fundamental elements, the coupler of closely placed disks and the butt-joint of disks. The coupler can be used for extracting the light from a disk laser. It was shown that the efficiency of the light extraction can be over 70% by the coupler. A mode size converter and a tunable filter combined with couplers were numerically demonstrated. The joint can be applied to a compact and sophisticate optical wiring in a large scale circuit, since the joint loss estimated was as low as 0.1 dB.