EPIPPROP (formally EchelleCAD) is is a unique and innovative tool for the modelling and optimisation of Echelle grating based planar lightwave components, in particular for wavelength division multiplexing applications.

EPIPPROP derives from the Greek word επίπεδο or "epipeda" which means layer or plane. EPIPPROP is a tool for simulating WDM devices that include a wide dielectric layer where a beam of light is confined vertically but is free to expand over large distances laterally – a geometry seen in the star couplers of AWGs and in planar Echelle gratings. EPIPPROP has efficient numerical techniques for modelling such wide layers – much more efficient than traditional techniques like BPM. Currently EPIPPROP can only model Echelle-based devices but it is hoped that it will model AWGs too in the future.

Echelle gratings provide a very efficient method for wavelength de-multiplexing (WDM) with a small footprint: they are typically much smaller than arrayed waveguide gratings (AWG) and offer simpler layouts. Photon Design provides in EPIPPROP the first commercial 3D Echelle simulation package. Using AWGs? Why not see if an echelle grating would be better!

  • 3D fully vectorial modelling of echelle gratings
  • Ultra fast propagation in the free-space region using analytic diffraction theory
  • Built-in fully vectorial 2D+z finite-difference waveguide mode solver: FIMMWAVE's FDM Solver
  • Tunable template gratings for Rowland circle and bifocal point stigmatic designs
  • Import any arbitrary user-defined grating
  • I/O waveguide arrays support multi-mode waveguides and arbitrary polarisation
  • Accounts for all diffraction orders
  • Flat and curved facets
  • Supports any grating surface, including metals with complex refractive index
  • Control tilt on grating facets in the plane for any blazed grating
  • Tilt the grating out of plane to model non-vertical facets
  • Simulate multiple vertical slab waveguide modes and the coupling between them
  • Simulate tapering and cross-coupling between adjacent waveguides (with FIMMPROP)
  • Export any design layout to a multilayer GDS-II file-from CAD to Fab in one click!

Example 1. Rowland Echelle Grating
The EPIPPROP interface allows you to design Rowland echelle gratings. The layout can be generated in the user interface or imported from a text file. A schematic view of a Rowland circle echelle grating in EPIPPROP is shown below.

Rowland Eschelle Grating Rowland Eschelle Spectra

Example 2. Bifocal Point Stigmatic Design
The EPIPPROP interface allows you to design bifocal point stigmatic echelle gratings. The layout can be generated in the user interface or imported from a text file. A schematic view of a stigmatic echelle grating in EPIPPROP is shown below.

Stigmatic Eschelle Grating Stigmatic Eschelle Spectra

Example 3. Modelling tapering and cross-talk in I/O waveguide arrays
The effect of tapering in the input and output waveguides in echelle gratings can be modelled using EPIPPROP combined with FIMMPROP. This will allow you to characterise the amount of unwanted cross-talk introduced by cross-coupling between neighbouring waveguides, and the associated deterioration in performance for the Echelle grating.

Spectra obtained with and without modelling the cross-coupling in the case of a non-optimum waveguide array can be found below. You can see that the cross-coupling introduces a fairly high level of cross-talk in the output spectrum as the transmission peak becomes wider when the cross-coupling in the taper is introduced (see arrow).

Cross-talk in I/O Waveguides

The corresponding EPIPPROP/FIMMPROP simulation showing the cross-coupling in the input waveguide array is shown below.

Cross talk in I/O Waveguides

GDSII Export
EPIPPROP allows you to export complete designs to GDS-II with the click of a button, for viewing using third-party GDS-II viewers and for manufacture.

Free Evaluation Available
A free 30-day trial of EPIPPROP is available. Please contact us for more information.