Noise in Frequency-Resolved-Optical-Gating Measurements of Ultrashort Laser Pulses

Abstract

Frequency-resolved optical gating[1, 2] (FROG) is a technique that uses a phase-retrieval algorithm to obtain the intensity, I(t), and phase, ϕ(t), from a measured spectrogram of the pulse. Previous simulations have shown that, for noise-free data, the algorithm retrieves the correct intensity and phase for all pulses attempted, including those with complex intensity and phase structure. In practice, however, noise is present in actual FROG traces, and here we discuss the effects of noise on FROG and image-processing techniques to improve the retrieval.