CrystalWave

CrystalWave is a design environment that has been created from the ground up for the layout and design of planer photonic crystals.

CrystalWave is the only commercial software that includes a Finite Difference Time Domain (FDTD) Engine, a Plane Wave Expansion (PWE) Engine, a Finite Element Frequency Domain (FEFD) Engine, and an optimizer in one software package.

  • Powerful, user-friendly interface
  • Integrated fast 2D and 3D FDTD simulation engines
  • Clustered FDTD versions available
  • True multiprocessor capability
  • Native 64-bit version available
  • Active-FDTD module allows modeling of semiconductor gain
  • Very fast innovative FEFD engine
  • PWE Engine for band structure analysis
  • Automatic optimization
  • Output to GDSII with structure and array reference support
  • Script automation

Platforms

PC: x86+x64: Win2000/XP/Vista/7, 1GB RAM, 2GHz or better recommended.


The Layout Editor


CrystalWave provides probably the most powerful, user-friendly graphical user interface for the design of photonic crystals available on the market today.

You can use the mouse to lay out atoms in lattices, point and line defects, quickly and as easily as using a common drawing package; creating with ease even the largest of structures with tens of thousands of atoms.
Numerical input allows fine control of lattice parameters and atom positions, shapes and sizes. You can also use the script system to fully automate the construction of even the most complex structures.

  • 2D and 3D photonic crystal lattices
  • Hexagonal, rectangular and any other regular lattices

  • User may specify both lattice vector directions and both lattice spacings
  • Atoms may be circular, elliptical, rectangular, regular or irregular polygons
  • Tapered and tilted holes and other non-vertical etches
  • Easy to change the positions, shapes and sizes of large numbers of atoms
  • Easy to place single and line defects, Individual atoms may be offset from their lattice points
  • Free rotation of any object
  • Multiple crystals, e.g. one region with lattice vectors at 0° and 60° and another with vectors at 5° and 65°
  • Definition of conventional waveguides into the lattice
  • Multi-level undo/redo Constraint system to build complex structures by joining elements together

GDSII Export


Export your masks and layouts in just a click. CrystalWave allows you to export complete photonic designs to GDS-II with the click of a button, for viewing with third-party GDS-II viewers and for manufacturing.

The following GDS-II features have been implemented to produce a GDS-II file optimized for photonic crystal layouts - substantially reducing file size over a general purpose tool.

  • Dark field GDSII
  • Structure references
  • Array references
  • Advanced GDS-II version and resolution control

FDTD Engine


The CrystalWave framework includes a highly efficient 2D or 3D FDTD (Finite Difference Time Domain) Engine to simulate the propagation of light through your designs. Independent tests have shown that Photon Design's 3D FDTD Engine to be easily the fastest for many applications and at the same time using much less memory than other implementations


Overview

  • 2D and 3D FDTD engine
  • Very fast speed optimized algorithm
  • Grid discretization optimized for photonic crystal lattices
  • More memory efficient than competing products.
  • Advanced memory reducing techniques
  • Sub-gridding - ability to create 2x, 4x or greater increased resolution in localized region

Materials

  • Transparent and lossy materials
  • Dispersive materials including metals, including Debye, Drude and mixed Drude/Lorentz models
  • Non-linear materials including chi2 and chi3
  • Anisotropic refractive index - general symmetric tensor
  • Magnetic materials
  • Graded index materials

Boundary conditions

  • High performance PMLs on all six faces
  • Dispersive PMLs e.g. to match metals touching the boundaries
  • Metal, magnetic and periodic boundary conditions

Sources

  • Built-in accurate mode solver for excitation of waveguide mode
  • Single dipole source or volume of incoherent dipoles (e.g. for modeling an LED)
  • Plane wave source, Gaussian profile source
  • Arbitrary beam source, including beam direction, focal point, polarization and intensity profile

Sensors

  • Measurement of power in waveguide modes
  • Frequency domain results: Fourier analysis
  • Q-Factor calculator - calculate Q in typically 1/4 the time compared to using a Fourier Transform
  • Built-in Far Field Calculator
  • Net flux, forward flux and backward flux sensors, versus time, frequency or wavelength.
  • Box sensors - measure total flux in/out of a box - useful for e.g. photo detector efficiency simulation

Additional features

  • Storing / Restoring results from an FDTD calculation
  • Batch manager - submit multiple jobs to the engine at same time
  • Run time monitoring of evolving fields
  • Video capture - generate a movie of your FDTD simulation using any codec installed in your PC

FDTD Cluster System


The Cluster Version provides scalable compute power for the FDTD engine. This allows you to solve problems that are too big to run on a single PC, and also to solve problems more quickly.

  • All control is via the familiar software user interface
  • All cluster management occurs via the Cluster Management Interface, including installation of nodes
  • Once set up, all cluster control occurs transparently to the user
  • Linux/x86 and Windows 2000/XP/Vista cluster nodes
  • 3GB per cluster node (XP), 2GB per node (Linux-32), 3.5GB per nodes (Linux64 or Win64 OS)
  • 64 bit Linux and Windows nodes - virtually unlimited memory
  • Both 1D and 2D domain tiling (division of 3D problem into smaller elements)
  • Automatic load balancing – giving slower nodes less work to do
  • Support for SMP – each node can have multiple CPUs and/or multi-core CPUs

Performance
Photon Design's 3D FDTD Engine has constantly outperformed competing products, usually by a significant margin. The exact performance obtained under cluster operation is dependent on several things such as network bandwidth, domain size, but as a guideline you can typically expect a problem using at least 1GB per node to run better than 90% of the ideal.

The Windows cluster is designed as a convenient ad-hoc clustering setup where unused PCs on your network can be conveniently added to a cluster calculation with little trouble.

The Linux version of the cluster FDTD is designed for more dedicated high-performance cluster use. In this scenario typically the compute nodes are on a private network, inaccessible from designers’ desktop PCs and accessible only through a “head node”. This configuration is shown below.


Active-FDTD Module


The Active-FDTD add-on provides additional capabilities to the FDTD Engine to model semiconductor gain. It allows you to model the effect of population inversion to produce optical gain. Now you can at last model photonic crystal and other micro-cavity lasers realistically.

  • Rate equation model of carriers including spontaneous & stimulated recombination, injection current
  • Multiple-Lorentzian gain model, with automatic fitting to a set of gain curves
  • Convergence Acceleration gets the device into the correct steady state more quickly
  • Fully integrated into the standard user interface
  • Current injection can be readily injected anywhere you want

Applications include photonic crystal lasers and VCSELs.

Band Structure Analyser


The analysis of the band structure of a periodic lattice is a very useful starting point for a photonic crystal circuit design. In essence it computes the solutions of a structure with infinite periodicity. This can be a "bulk" lattice but could also be a line defect, telling you when the lattice is opaque, when a line defect is single mode and so on.

The Band Structure Analyser will compute the Bloch (periodic) modes of a photonic crystal lattice with 2 or 3 dimensional periodicity. It will automatically identify the TE and TM band gaps of your structure and evaluate the Bloch mode profiles at any point.

  • Full integration with the CrystalWave framework
  • PWE (Plane Wave Expansion) based engine for best computation in the frequency domain
  • 2D and 3D simulation modes
  • Supports all lattices definable in the CrystalWave layout editor
  • Generates w/k band diagrams for TE-like and TM-like polarizations
  • Automatic detection of band gaps
  • Easily plot the Bloch modes from any point on the w/k band diagram
  • Calculate effective index, group index and dispersion of the Bloch mode
  • Real and lossy materials
  • Speed optimized calculation engine takes advantage of any symmetries
  • Automatic scanners for generation of "band maps" e.g. against lattice period or hole size

Frequency Domain Engine


The FEFD (Finite Element Frequency Domain) Engine is a powerful state of the art 2D Maxwell solver for propagation within an arbitrary photonic structure. The FEFD Engine allows you to compute a steady state (single frequency) response for your device and is the first frequency domain solver that that is capable of solving problems currently only manageable with FDTD methods.


The FEFD Engine is able to perform calculations of complex 2D layouts even orders of magnitude faster than any competing tool.

  • Based on new efficient numerical techniques
  • Exclusive algorithm
  • Real index and lossy 2D structures
  • Unparalleled speed
  • High delta-n capability
  • Integrated with the FDTD Engine
  • Wide range of sources and sensors
  • High speed and low numerical noise makes it ideal for automatic optimization

Kallistos Optimizer


Photon Design's market leading automatic optimizer is available to drive either the FEFD Engine or the FDTD Engine – together these two tools will reduce design times to a fraction of what is currently possible.

The Kallistos module adds powerful automatic optimization to your CrystalWave design suite. It will save you many hours of design time if not days and will often locate new designs that you are unlikely to obtain manually by trial and error. You can readily find global optima for 3 or 4 parameters of your choice or local optima for 10 or more. Photon Design has used this internally to develop photonic crystal components with world record efficiencies.

From this…. .…to this within minutes


A small sample of publications using results from CrystalWave

"Experimental verification of numerically optimised Photonic Crystal Injector, Y-Splitter and Bend" - M. Ayre, T.J. Karle, L. Wu, T. Davies and T.F. Krauss. IEEE Journal on Selected Areas In Communications, vol. 23, pp. 1390-1395, 2005

"New design rules for planer photonic crystal devices obtained using automatic optimisatino, leading to record efficiencies" - T.P. Felici, A. Lavrinenko, D.F.G.Gallagher et al. Presented at the ECOC 2003 Conference, Rimini, Italy.

"Transmission of photonic crystal coupled resonator waveguide (PhCCRW) structure enhanced via mode matching" - Chongjun Jin, Nigel P. Johnson, Harold M. H. Chong, Aju S. Jugessur, Stephen Day, Dominic Gallagher and Richard M. De La Rue. Optics Express Vol. 13, No. 17, April 2005

"Photonic Integrated Circuits using Crystal Optics (PICCO)" - T.F. Krauss, R. Wilson, R. Baets, W. Bogaerts, M. Kristensen, P. I. Borel, L. H. Frandsen, M. Thorhauge, B. Tromborg, A. Lavrinenko, R. M. De La Rue, H. Chong, L. Socci, M. Midrio, D. Gallagher. ECIO 2003 p. 113-117, 2003

"in-plane Littrow lasing of broad photonic crystal waveguides" - O. Khayam, C. Cambournac, H. Benisty, M. Ayre, R. Brenot, G. H. Duan, W. Pernice. Applied Physics Letters, Vol. 91, 041111, 2007

"Integrated wavelength monitoring in a photonic-crystal tunable laser diode" - H. Hofmann, M. Kamp, A. Forchel, D. Gallagher, H. Benisty. Photonics and Nanostructures, Elsevier, col. 6, pp 205-212, 2008