reZonator is a powerful software for designing laser resonators and calculation the propagation of light beams (as gaussian so as ray vectors) in complex optical systems. It has a modern, user-friendly interface, so you need no specialized training or programming skills to use all of its functions and tools.

You can use the program for educational purposes. Still, it was created as a real working tool for computer modeling of laser cavities and currently used in a number of research organizations over the world.

It uses the might of the Qt framework to manage cross-platform operation and can run natively under Windows, Linux, and macOS. It is also open-source. Not all of the abilities of the old closed-source version 1 are available in the open-source version yet. Still, it is continuously evolving and accepts more and more features from the closed-source version while providing new cool features as well.

Key features

Optical systems

reZonator supports standing wave laser cavities and running wave (ring) resonators, as well as conventional single-pass systems, e.g., pump roads or beam expanders. M² beam quality factor also is taken into account for single-pass systems.

Optical elements

Programs' elements catalog contains many essential optical elements - ranges, lenses, spherical mirrors, crystals, and many more. The ABCD ray matrix algorithm used for simulation of optical elements, so you also can define your own element by providing its matrix.

Unrestricted design

It is possible to construct arbitrary optical system from proposed or user-defined optical elements. reZonator automatically creates a rendition of the system under investigation - almost as you could sketch it on a paper sheet or your drawing board.

Stability maps

For advanced system optimization, reZonator can compute cavity stability maps against values of one or two parameters of any element. It is possible to specify arbitrary contour lines for the contour stability map. Also, automatic computation of stability boundaries provided.

Wavefront calculation

reZonator can plot the size and the wavefront curvature radius of the Gaussian beam over one or a few elements, astigmatism also taken into account. It is possible to compute beam size at any position inside the system. Automatic determination of position and size of the waist at element where it is, calculation of the radius of diffractive divergence, and other parameters of the Gaussian beam provided.


Adjustment tool allows you for gradually changing any parameter of any element - just like you rotate a screw of some mirror mount or a translating stage. Any results instantly recalculated while parameter value is changed.

and more

Other convenient and useful tools and functions also available - repetition rate, beam parameters at all elements, misalignments of elements, "freezing" results, full plot customization, copying results to the clipboard, and more...

You can take a view of screenshots to estimate how the results of these and other functions look. Or you can look into a few tutorials to learn basic software features and concepts.

Both open-source and closed-source versions are freeware, and you may use them with no limitations. However, please don't forget to give credits to the project when you use achieved results in your publications. And if you need to redistribute this software, please include the reference to the original project home page (this site) into your distribution.

Any questions, comments, help, and critical words should be sent to the project e-mail or posted as issues on GitHub (if they relate to the open-source version).