Harold

Interface

Layers editor

HAROLD’s Layers Editor allows you to provide a complete specification of the epitaxial layer structure of your device. This will typically consist of: metal contact/heatsink layers, a substrate layer, bulk layers, QW and barrier (confinement) layers.

• For each layer you can specify (where applicable) the thickness, material, alloy composition and doping levels.

• Periodic structures can be defined, such as MQWs and DBRs (for VCSELs)

• Grading of composition and doping within layers are supported.

• You can also specify your own specialised Shockley-Reed-Hall recombination for individual layers in your structure.

Harold’s Layers Editor

Device editor

HAROLD’s Device Editor is used to define the basic properties of the Fabry-Perot device that is to be simulated, such as cavity length, width and the facet reflectivities. It also allows you to define such things as facet absorption, scattering loss, surface recombination parameters, heatsink properties and so on. Furthermore, one can use advanced parameters to fine-tune the spontaneous emission, gain, and capture escape models; and for 2D simulations one can define additional features such as a thermal overhang or suppression of current injection at the facets.

Harold’s Device Editor

Other editors

HAROLD also contains editors allowing you define your own trap definitions for modelling Shockley-Reed-Hall non-radiative recombination; a mesh policy editor which allows to use a specific simulation mesh for individual layers in your structure; and a quantum well level editor, should you want to experiment independently of HAROLD’s built-in Schrodinger solver.