Your source of photonics CAD tools


A WDM/DWDM model for AWGs and Echelle Gratings


What is Epipprop?

Epipprop is a unique and innovative tool for the modelling and optimisation of:

in particular for wavelength division multiplexing applications (WDM/DWDM).

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 or planar concave gratings. Epipprop has efficient numerical techniques for modelling such wide layers – much more efficient than traditional techniques like BPM.

Epipprop now provides all your WDM/DWDM tools in one box! 

Echelle Gratings and Planar Concave Gratings

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 grating simulation package. Using AWGs? Why not see if an echelle grating would be better!

Want to learn how to design and optimise Echelle gratings?

Our paper on Echelle grating design & optimisation using Epipprop is published in the IEEE Photonics Journal. This paper builds up on our experience of Echelle grating modelling and describes a new single-point stigmatic design for Echelle gratings: the Perfect Chirped Grating (PCG). It also offers a discussion on the Echelle grating design process and introduces a series of rules to improve the performance of any grating. The paper is available and open access.

You can also find some results obtained by applying the Perfect Chirped Grating design for silicon photonics in an article that we co-published with CEA-LETI. The article showed excellent agreement of the channel spacing and output wavelength positions between simulation and experiments.

Echelle gratings

A two stigmatic point grating with corner mirror total internal facets
and a perfectly chirped grating with distributed Bragg reflector facets.

Arrayed Waveguide Gratings

Arrayed waveguide gratings use a series of parallel waveguides of differing length to create a phase based device where light of different wavelengths are focused to a different position in space. They are widely used for wavelength de-multiplexing (WDM).

Looking to try designing an AWG? Epipprop provides a quick and easy design experience that allows the layout and ultrafast simulation of an AWG in any material platform.


Shown above is the layout of a compact silicon-on-insulator AWG and the simulated results. br /> You can see in the results the overlapping orders at each end of the spectra.