The boom in popularity of the Linux operating system in the past few years is resulting in, for example, the design of very low-cost laptop computers specifically around Linux. As is well known, the source code for Linux is available to everyone because Linux is released under the GNU General Public License, an open-source license. Now, optical researchers at the École polytechnique de Montréal (Montréal, Québec, Canada) are releasing their in-house optical-filter-design software, called OpenFilters, under the same license.
Used for the design of multilayer or graded-index filters, OpenFilters provides, in addition to the most-common filter characteristics, calculations on group delay, group-delay dispersion, ellipsometric variables, admittance and circle diagrams, electric-field distribution, and other information, as well as refinement, needle, step, and Fourier-transform capabilities. The researchers invite others to not only use OpenFilters free of charge, but also to examine its source code and modify it if needed, and collaborate with the Montréal group on the further development of the software (see Applied Optics, May 1, 2008, p. C219, for more detail on OpenFilters). Contact Stephane Larouche at [email protected].