Crosslight Software (Gloucester, Ontario, Canada) introduced the software package Photonic Integrated Circuit Simulator in 3D (PICS3D) in October 1996. Manufacturers can use this program to simulate operation of semiconductor lasers and other optoelectronic devices in a three-dimensional environment. It provides detailed modeling capabilities for the semiconductor material and layer geometry in the lateral and longitudinal dimensions. Typical computational times are on the order of an hour or so, and the common laser designs that can be optimized with PICS3D include distributed feedback (DFB), distributed Bragg reflector (DBR), and vertical-cavity surface-emitting-laser (VCSEL) structures. Existing structures can also be optimized to cut manufacturing costs. Among the benefits the software offers is the ability to cut research and development costs by tens of thousands of dollars through an hour or so of computer time rather than two-to-three months of device manufacturing on experimental designs that may not work.