Advanced Laser Diode Simulator (ALDS) is a user-friendly and powerful computer-aided design software package for modeling and simulation of semiconductor laser diodes.ALDS is a performance simulator which predicts the characteristics of a laser diode based on design specification and operation conditions. ALDS has a versatile hierarchial environment that allows for the flexible choice of models. Powerful physics-based and behavioral models are used, and the designers can work at different levels to focus on the design issue of their choice.