Surface ionization of diamond by femtosecond laser pulses: A comparative study of analytical models

This paper presents a theoretical study of femtosecond-laser–induced ionization processes on diamond surfaces based on three analytical models: the multiphoton (MP) ionization model, the Ammosov–Delone–Krainov (ADK) tunneling model, and the Ivanov–Yudin (IY) model. The models were employed to analyze the dependence of plasma density on laser intensity, frequency ratio, and temporal evolution. The results reveal that the MP model is effective at low intensities and high frequencies, the ADK model is more accurate under strong-field conditions, and the IY model captures nonadiabatic and time-dependent effects, serving as an intermediate bridge between the two. Overall, a comprehensive understanding of laser–matter interactions requires a hybrid use of analytical models or their integration with advanced computational techniques, and the findings provide valuable insights for applications in micro- and nanoprocessing technologies, optical and quantum device fabrication, and biomedical sensing.