
CAMFR (CAvity Modelling FRamework)
CAMFR is being distributed under a dual license scheme. All the code is released under the GPL, but a closed proprietary license scheme can be also provided. CAMFR was developed by Ghent University (Belgium) photonics group.
CAMFR is a fullvectorial Maxwell solver based on the eigenmode expansion method. Although it can handle general electromagnetic problems, its main focus is on applications in the field of photonics.
Capabilities:
 CAMFR treats the field as a sum of local eigenmodes in each zinvariant layer and does not rely on spatial discretisation and finite differences to solve Maxwell's equations (like other methods, e.g. FDTD, do).
 Since there is no spatial discretisation, CAMFR can be orders of magnitude faster than FDTD for a large class of structures.
 Incorporates advanced boundary conditions (like e.g. PML), which can drastically improve simulation accurary and speed.
 CAMFR is an ongoing active research project.
 Twodimensional Cartesian structures and threedimensional cylindrical symmetric structures
 CAMFR can be used to calculate:
 The scattering matrix of a structure
 The field inside a structure, for any given excitation
 Band diagrams of an infinite periodic structure
 Threshold material gain and resonance wavelength of laser modes
 The response to a current source in an arbitrary cavity
 Structures terminated by a semiinfinite repetition of another structure
 Defining structures is quite straightforward, either layerbylayer, or using geometric primitive shapes. There are also integrated plotting routines for rapid simulation feedback.
 CAMFR is conceived as a C++ framework, with all the algorithms implemented in terms of abstract waveguides and scatterers. This makes it extremely easy to extend CAMFR to new geometries.
 The end user does not deal with this C++ code directly, but rather through bindings to the Python scripting language.
Applications:
 Wavelengthscale microstructures (like photonic crystal devices)
 Lasers (like verticalcavity surfaceemitting lasers)
 Lightemitting diodes (like resonantcavity LEDs)
Related Publications:
 H. Wenzel et al., "A comparative study of higher order Bragg gratings: coupledmode theory versus mode expansion modeling," IEEE J. Quantum Electron. 42, 64 (2006).
 P. Bienstman et al., "Modelling leaky photonic wires: A mode solver comparison, Opt. and Quantum Electron. 38, 731 (2006).
 B. Luyssaert, P. Bienstman, P. Vandersteegen, P. Dumon, and R. Baets, Efficient Nonadiabatic Planar Waveguide Tapers, J. Lightwave Technol. 23, 2462 (2005).
 G. Roelkenset al., Integration of InP/InGaAsP photodetectors onto silicononinsulator waveguide circuits, Opt. Express 13, 1010210108 (2005).
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FIMMPROP
Commercial software software sold by Photon Design.
FIMMPROP is a tool for simulating two and threedimensional propagation phenomena in waveguides based on the eigenmode expansion (EME) method.
Capabilities:
 Fully vectorial
 The EME method enables the fields to be calculated using fast semi analytical methods.
 The speed and nature of the calculations allow the propagation to be treated in a fully bidirectional manner, taking into account all the reflections at intermediate joints.
 This makes FIMMPROP capable of modeling structures which are insolvable by other methods such as BPM.
 Modeling devices with strong internal reflections, such as waveguides terminated by a tilted facet.
 Use of semianalytical modal methods by FIMMPROP permits calculations to achieve high accuracy even for more complicated structures.
 Zvariant structures are modeled by joining two or more straight sections together.
 Once the local modes of the structure are found then propagation along the length of the section is nearinstantaneous.
 Calculations permit both transmission and reflection coefficients of the modes at each joint to be determined for use in the fully bidirectional propagation algorithm.
 Structures with Zvarying crosssections such as tapers and Yjunctions are computed using sophisticated extensions to the EME method.
 The algorithm builds a scattering matrix description of the device and all its elements, which means that once the matrices are generated, the response to many different input profiles can be found without further computation, e.g. one might want response to both TE and TM excitation.
 If the structure is altered, the routine needs only recalculate the elements that have changed.
Applications:
 MMI couplers
 Mode converters
 Codirectional couplers (e.g. polarization converters)
 Bends
 Periodic structures
 Tilted joins
 Facets and free space regions, e.g. for waveguidegapfiber simulations.
 Propagation in free space is treated with a special efficient algorithm based on plane wave expansion techniques
Related Publications:
 N. N. Feng et al., Lowloss compactsize slotted waveguide polarization rotator and transformer, Opt. Lett. 32, 2131 (2007).
 D. J. Y. Feng et al., Waveguide couplers with new power splitting ratios made possible by cascading of short multimode interference sections, Opt. Express 15, 1588 (2007).
 M. Hiltunen et al., "Modeling of Aperiodic Fractal Waveguide Structures for Multifrequency Light Transport," J. Lightwave Technol. 25, 1841 (2007).
 L. M. Augustin et al, A Single EtchStep FabricationTolerant Polarization Splitter, J. Lightwave Technol. 25, 740 (2007).
 F. Riboli et al., "Integrated Optical Microcavity Infiltrated by Liquid Crystals for CWDM Applications," Opt. and Quantum Electron. 38, 249 (2006).
 T. J. Karle et al., Observation of Pulse Compression in Photonic Crystal Coupled Cavity Waveguides, J. Lightwave Technol. 22, 514 (2004).
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OlympIOs Bidirectional Eigenmode Propagation (BEP) Module
Commercial software sold by OlympIOs.
The bidirectional eigenmode propagation method (BEP) is one of the modules OlympIOs currently offers for simulating the propagation of light through planar waveguide structures.
Capabilities:
 OlympIOs is the only commercially available platform that integrates the BEP method with the well known Beam Propagation Method (BPM) in a single user interface. The enduser can simulate (parts of) the device using the fastest and most appropriate method.
 Analysis of waveguide structures that include large waveguide sections invariant in the propagation direction
 Includes guided and radiation modes
 Simulates reflections
 Perfectly Matched Layer (PML) boundary conditions
 Can handle high index contrast
 Can handle very wide propagation angles
 Avoids redundant calculations in vary runs
 Generic simulation features:
 Extensive parameterization capabilities
 Vary runs
 Material library
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