Your source of photonics CAD tools


A bi-directional optical propagation tool

Silicon Photonics Modelling

Simulations with FIMMWAVE and FIMMPROP software

FIMMPROP is probably the most widely used software propagation tool for the modelling of silicon photonics. It is a very efficient full vectorial 3D model with a full CAD interface - including GDS-II export - capable of modelling propagation in a large variety of high-index waveguides.

Typical designs that can be modelled with FIMMPROP include MMI couplers, directional couplers, Y-junctions, spot-size converters, mode-size converters, grating couplers, ring resonators etc.

Benefits of EingenMode Expansion for silicon photonics

When compared with other methods such as BPM, FEM or FDTD, FIMMPROP and the EigenMode Expansion (EME) method offer many benefits to model silicon photonics:

  • EME is a rigorous method: no slowly varying approximation (unlike BPM which is approximate!)

  • FIMMPROP is fully vectorial: can handle high index contrast, even for shallow or partial etch

  • Wide angle capability (unlike BPM which can only model a small range of angles)

  • High speed: fast propagation in long waveguides, use of semi-analytical methods, fast design optimisation etc. FIMMPROP is much faster than FEM or FDTD!

  • FIMMPROP's unique adaptive taper algorithm allows it to model z-varying structures very efficiently.

  • Fast scanning and optimisation: vary some design parameters instantly!

  • Effortless integration of a FIMMPROP component simulation with our photonic circuit simulator PICWave for the modelling of active and passive PICs.


The examples below are a selection of FIMMWAVE and FIMMPROP applications focusing on silicon photonics.

Modes of a Silicon Waveguide

Fiber to Chip Silicon Vertical Grating Coupler

Inverted Taper for Fiber to Silicon Chip Coupling

Silicon Optical Ring Resonator Filter

Silicon MMI Coupler for Wavelength Demultiplexing

Intensity profile for the ring coupling
Intensity profile in a silicon ring coupler (full results here).


FIMMPROP is used by most of the major players in silicon photonics, and it has been used extensively in publications over the past few decades - just type "FIMMWAVE silicon" or "FIMMPROP silicon" in Google Scholar! You can find a small sample below.

Authors' affiliation Reference
Intel Haisheng Rong, Ansheng Liu, Richard Jones, Oded Cohen, Dani Hak, Remus Nicolaescu, Alexander Fang and Mario Paniccia, "An all-silicon Raman laser", Nature 433, 292-294 (2005)
IBM Eric Dulkeith, Fengnian Xia, Laurent Schares, William M. J Green, and Yurii A. Vlasov, "Group index and group velocity dispersion in silicon-on-insulator photonic wires", Optics Express, Vol. 14, Issue 9, pp. 3853-3863 (2006)
UCSB H. Park, A. W. Fang, R. Jones, O. Cohen, O. Raday, M. N. Sysak, M. J. Paniccia, and J. E. Bowers,"A hybrid AlGaInAs-silicon evanescent waveguide photodetector", OPTICS EXPRESS 6044-6062, Vol.15, No.10 (2007) 
Gent University T. Claes, J.G. Molera, K. De Vos, E. Schachtb, R. Baets, P. Bienstman, "Label-Free Biosensing With a Slot-Waveguide-Based Ring Resonator in Silicon on Insulator," IEEE Photonics Journal, 1, 3, pp.197-204 (2009) 
TNO Wouter J. Westerveld, H. Paul Urbach and Mirvais Yousefi, "Optimized 3-D Simulation Method for Modeling Out-of-Plane Radiation in Silicon Photonic Integrated Circuits", IEEE Journal of Quantum Electronics, 47, 5, pp. 561-568 (2011) 
Molex A. N. M. M. Choudhury, T. R. Stanczyk, D. Richardson, A. Donval, R. Oron and M. Oron, "Method of Improving Light Coupling Efficiency Between Optical Fibers and Silicon Waveguides", IEEE Photonics Tech. Lett. 17, 9, pp. 1881-1883 (2005)  
University of Texas at Austin A. Hosseini, H. Subbaraman, D. Kwong, Y. Zhang, R. T. Chen, “Optimum Access Waveguide Width for 1xN Multimode Interference Couplers on Silicon Nanomembrane,” Optics Letters, vol. 35, 2864-2866 (2010) 
University of Bristol A. Politi, M.J. Cryan, J.G. Rarity, S. Yu, J.L. O'Brien, "Silica-on-Silicon Waveguide Quantum Circuits", Science, vol. 320 (5876), pp. 646-649 (2008)
Universitat Autonoma de Barcelona V.J. Cadarso, A. Llobera, I. Salinas, D. Izquierdo, I. Garces, C. Domınguez, "Silicon-based rectangular hollow integrated waveguides", Optics Communications 281, p. 1568–1575 (2008)