Lightwave explorer is an open source nonlinear optics simulator, intended to be fast, visual, and flexible for students and researchers to play with ultrashort laser pulses and nonlinear optics without having to buy a laser first. Supports both CUDA and CPU calculations. Its purpose and goals are:

• Easily-extensible database of materials
• Multiple physical models, including the unidirectional nonlinear wave equation and finite-difference time-domain approaches.
• Efficient code so that complicated systems can be simulated in 3D: Real laser pulses can be messy, and if they weren't so before a nonlinear crystal, there's a good chance they are after. Multidimensional simulations open up the weird world of spatiotemporal couplings. You have options for very fast simulations when there's a symmetry to use (e.g. cylindrical), alongside fully 3D propagation
• A graphical interface that lets you see what you're doing
• A flexible sequence mode to string together elements: not just nonlinear crystals, also spherical or parabolic mirrors, apertures, filters, free space propagation and more
• Fitting/optimization routines
• A Python module for easy postprocessing