A Toolkit for Time-Dependent 3D Thermal Modeling in KTP Crystal under Pulsed-Gaussian Second-Harmonic Generation Operation

We present an open-source toolkit for modeling the time-dependent three-dimensional temperature distribution in a cylindrical KTP crystal under repetitively Pulsed-Gaussian pumping, relevant to thermally influenced second-harmonic generation. The toolkit provides a Fortran finite-difference time-domain solver of the heat equation with temperature-dependent thermal conductivity and Robin boundary conditions (convection and radiation). It accepts pump, geometry, and material parameters as inputs and returns spatiotemporal temperature and derived conductivity data along radial, axial, and transverse directions. Relative to the prior published implementation of this problem, the toolkit packages the method as a versioned repository with a tagged release and archived digital identifier. Example datasets are included with filenames that encode pulse energy, repetition frequency, pulse count, and duration. The implementation uses the memory- and runtime-saving algorithm described for efficient multi-pulse simulations. The toolkit's validity follows from the reference implementation that treats KTP with convection and radiation boundaries and temperature-dependent conductivity, and the included code and results mirror those calculations and outputs. The toolkit is available as an open-source GitHub repository and is released under the MIT License as version v1.0.1, with a permanently archived distribution identified by DOI 10.5281/zenodo.17362545.