Characterization of Ultrashort Laser Pulses Using Frequency-Resolved Optical Gating (FROG)

Frequency-Resolved Optical Gating (FROG) is a key technique in nonlinear optics, providing comprehensive spatiotemporal characterization of ultrashort laser pulses, including both intensity and phase. By spectrally resolving a nonlinear autocorrelation trace into a spectrogram, FROG overcomes the limitations of conventional intensity-only measurements. Through iterative phase retrieval, FROG extracts critical parameters such as pulse duration, chirp, and temporal structure with sub-femtosecond precision. Its versatility makes it indispensable in ultrafast science, supporting applications from attosecond spectroscopy to ultrafast laser development. In this paper we are interested to characterize the pulse with width duration : , and using a FROG technique. We showed that each pulses duration presents unique challenges and opportunities for characterization. Using pulse simulations require less computational power due to relatively slower dynamics, allowing for quicker retrieval with less sensitivity to noise. With pulse is more detailed simulations needed to account for broad bandwidth and potential nonlinear effects. Then using pulse require the most detailed and computationally intensive simulations, particularly to mitigate noise and account for rapid phase changes.