In booth 3553 at SPIE Photonics West 2025 in San Francisco, CA, USA (25-30 January), photonic simulation CAD software developer Photon Design Ltd of Oxford, UK is previewing results from its upcoming quantum dot module being added to its established laser simulator HAROLD. The expansion to HAROLD will allow simulation of gain and absorption spectra from epitaxy structures with multiple quantum dot layers using an eight-band k.p model and a full 3D stress-strain model. The module was developed and validated in collaboration with Cardiff University, which has expertise in compound semiconductor photonics...