PIPES - diffraction modeling software <contact>gleb@duteisp.et.tudelft.nl <description><url>http://guernsey.et.tudelft.nl/pipes/pipes.html</url> Pipes is a small package which can help you to build models of optical devices in the frame of scalar diffraction theory. Package consists of expandable set of filters, the filters can be connected through system pipelines in any order within the shell environment to form the model of optical system. In some respect it can be considered as ``scalar diffraction'' extension of standard set of UNIX tools such as ``grep'' or ``sort''. The program operates on one large structure which contains a square two-dimensional array of complex amplitudes of electromagnetic field in a propagating light beam. You can filter the field through normal and Gaussian apertures, lenses, you can propagate it. you can split your beams and you can mix them again. You can write to a file the intensity and phase distributions from any point of your model and you can use Gnuplot (which is free) as simple user-end graphical interface to observe the results of your computations. Beam propagation, diffraction , interference and even laser resonators can be modeled with very short and simple shell scripts. The approach used is absolutely different from ray-tracing, so the package can not be used for lens design and optimization. <environment> The source code is compact, but to run it you need fast computer with at least 8 MB RAM and 10 MB of free disk space. The package was developed and tested on a LINUX/486DX2-66/20MB computer, which proves to be enough for modeling of simple devices. <keywords>application library; diffraction modeling <category>application </urc>