LIFSim enables the simulation of excitation spectra for diatomic molecules such as NO, OH, SiO, and O₂. By adjusting parameters like laser wavelength, environmental conditions (temperature and pressure), and gas composition, the software provides predictions of fluorescence excitation behavior. These simulations are crucial for designing selective and quantitative diagnostics, particularly in environments with complex chemical interactions. Researchers can use this feature to explore excitation transitions and optimize experimental setups for temperature and concentration measurements.


The software simulates emission spectra resulting from laser-induced fluorescence in various diatomic species. Users can define laser characteristics, spectrometer parameters, and environmental conditions to predict fluorescence signals. This tool is invaluable for understanding the spectral distribution of emitted light and optimizing detection systems in combustion and other reactive flows. By accounting for collisional quenching and line broadening, the emission spectra simulation supports detailed analysis and experimental design.

LIFSim facilitates the modeling of absorption spectra by integrating temperature- and pressure-dependent effects. These simulations provide insights into how diatomic molecules absorb laser light, revealing their population distributions and transition efficiencies. The feature helps researchers identify suitable wavelengths for probing target species and understanding the interaction between laser profiles and molecular absorption lines, essential for non-invasive diagnostics in high-temperature and chemically reactive environments.

The temperature sensitivity analysis tool identifies optimal spectral regions for multi-line LIF thermometry. By simulating and evaluating fluorescence spectra at different temperatures, the software highlights regions with the highest sensitivity for temperature measurements. Researchers can use this feature to minimize uncertainty in temperature fits, ensuring reliable diagnostics in challenging experimental conditions. This tool is especially useful for selecting spectral ranges in noisy or interference-prone environments.

LIFSim allows users to extract temperature information from experimental excitation spectra. This functionality supports both single-spectrum analysis and spatially resolved temperature mapping through multi-line imaging. By comparing measured spectra to simulated models, the software determines temperature with high accuracy, even in the presence of background noise or scattering. This feature is particularly useful for thermometry applications in combustion and other high-temperature processes. 

LIFSim includes tools to infer the mole fraction of target species based on their fluorescence signals. By combining information from spectral line intensities and temperature measurements, the software provides semi-quantitative estimates of species concentrations. This feature is ideal for comparative studies and understanding relative changes in molecular composition across varying conditions in experimental setups.

LIFSim is designed with a modular architecture, allowing users to easily add new molecular species or update existing spectral data. The software accepts detailed input, including line lists, partition functions, Einstein coefficients, and other spectroscopic parameters critical for the simulations. These datasets can be imported and stored for future use, making it simple to expand the library to accommodate additional diatomic species. This modular approach ensures that the software can adapt to emerging research needs, enabling facilitated modeling of species-specific fluorescence behaviors across diverse applications.

The simulation of collisional effects, such as quenching and broadening, is another key feature of LIFSim. The software allows users to define gas compositions through flexible input files, which specify the fractions of various collision partners in the probe volume. Additionally, LIFSim supports further implementation of collision models, enabling researchers to incorporate custom data or models for quenching and collisional broadening specific to their target species. This adaptability ensures updated representation of real-world conditions, facilitating the analysis of fluorescence behavior under complex environmental parameters.