Cloud native EDA tools & pre-optimized hardware platforms
The RSoft Photonic Device Tools are integrated with Synopsys Sentaurus TCAD products to provide streamlined, multi-disciplinary simulations of complex optoelectronic devices. It is a bi-directional interface that uses native file formats for efficient, robust analysis – with no messy file format conversions.
Sentaurus TCAD geometry can be imported into RSoft photonic design tools such as FullWAVE for finite-difference time-domain (FDTD) analysis, BeamPROP for rapid analysis of silicon photonics devices and DiffractMOD for diffractive optical structure analysis.
In addition, RSoft photonic design tools are integrated into the Sentaurus Workbench for easy inclusion in a Sentaurus TCAD workflow. This allows designers to simulate silicon modulators, for example, by passing complex index profiles from Sentaurus Device to BeamPROP for optical simulation, or to simulate waveguide photodetectors by passing absorption profiles from FullWAVE or BeamPROP to Sentaurus Device for electronic simulation.
Figure 1. RSoft tools are seamlessly integrated into Synopsys Sentaurus Workbench
The interface between industry-leading tools Sentaurus TCAD and RSoft photonic design software provides a powerful, unique approach for modeling and analyzing optoelectronic devices.
Model and analyze a phase shifter for use in a 3D free-carrier silicon modulator with longitudinal P-N junctions. The structure varies in both transverse and longitudinal directions and requires simulation by a 3D electronic solver such as Sentaurus TCAD.
Simulation tools used:
Sentaurus Structure Editor is used to model the modulator structure, doping calculation and electronics. Sentaurus Device Simulator is used for 3D electronic simulation to calculate properties such as electron density, hole density, and complex refractive index perturbation. This calculation was performed at several bias points. Finally, RSoft BeamPROP is used to perform the optical beam propagation analysis at each bias point to calculate the resulting phase shift.
Figure 2. Silicon modulator modeled in Sentaurus Structure Editor
The result, shown in Figure 3, shows the guided mode in the waveguide, the amplitude and phase of the propagating field, and the phase shift vs. bias. The phase shift can be used to calculate the properties of the phase shifter such as Vπ, the figure of merit of the modulator.
Figure 3. RSoft BeamPROP simulation results for silicon modulator
Calculate the I-V curve for a Ge photodetector integrated on top of an Si waveguide separated by a thin SiON layer. A taper is used to convert the optical mode from Si to Ge. Roughly 30 tungsten (W) pillars are alternately connected to one of two bias contact. SiO2 surrounds the entire structure.
Simulation tools used:
Sentaurus TCAD tools are used to draw the structure geometry, shown in Figure 4.
Figure 4. SiGe photodetector modeled in Sentaurus Device
The geometry is then passed to the RSoft tools, which calculate the 3D optical generation profile within the structure. RSoft BeamPROP or FullWAVE tools can be used to calculate the optical generation profile. The Sentaurus TCAD tools then perform the electronic simulation to calculate the I-V curve.
See Figure 5 for the photodetector analysis results from the RSoft and Sentaurus TCAD tools.
Figure 5 a) Structure seen in the RSoft CAD; b) Optical Generation Profile calculated by RSoft; c) I-V curves calculated by Sentaurus TCAD.
BeamPROP, based on the BPM algorithm, offers an extremely fast alternative to FDTD simulation with reasonable accuracy. Figure 6 shows a comparison of I-V curve results using optical data from FullWAVE (FDTD) and BeamPROP (BPM). The BPM results are similar to the FDTD results and are obtained approximately 50x faster than FDTD.
Figure 6. Comparison of I-V curve results using optical data from FullWAVE (FDTD) and BeamPROP (BPM).