
VCSEL Module
Harold VCSEL 3-D Laser Module
Introduction
HAROLD/VCSEL is a full 3D model, computing the multiple optical cavity modes, electrical drift-diffusion, heat-flow and electron-photon interactions. Building on Photon Design’s 30 year experience in both EM and laser diode modelling, this provides a comprehensive integrated design environment for a variety of the VCSEL variations being explored by industry today, including QW materials, tunnel junctions, current blocking oxide apertures and more.
Modelling Scope
HAROLD/VCSEL covers the three main areas of modelling:
Optical:
- Built in full-vector 3D cavity mode solver for multiple modes
- Scattering off oxide windows, contact apertures
- Built-in far-field calculator
- Built-in QW gain model, with databases for common materials InGaAsP, AlGaAs, InGaAlAs etc.
Electrical:
- Self Consistent Poisson/drift-diffusion electrical model
- Current confinement via oxide apertures or tunnel junctions
- Electrical Leakage
Thermal:
- Full 3D thermal heat-flow model
- Joule(I2R) heating, contact resistance heating
- Recombination, FCA, IVBA heat sources
VCSEL Editor
Starting from your epitaxy recipe our updated user interface in Harold/VCSEL will make it easy to design your VCSEL, with features for easy definition of DBRs and positioning of contacts, tunnel junctions and oxide layers.
Simulation Results
Harold/VCSEL is capable of generating a wide variety of simulation results, giving a detailed insight in device behaviour. These include:
- Temperature, heat sources
- Current and carrier density
- Optical mode/far-field
Detailed Cross-Sectional and Plan Profiles

Steady State Device Results
- LIV Curves
- Temperature and dissipated heat source powers
- Recombination currents
- QW gain, carrier density, FCA/IVBA
Time-Domain Results Spectra
- Time evolution of optical power and carrier density
- Laser output optical spectra (power spectral density), RIN spectra
- Lasing linewidth