ABSTRACT
A new (to our knowledge) method for generating the modified spectrum autointerferometric correlation (MOSAIC) trace from the second-harmonic generation frequency-resolved optical gating (SHG FROG) dataset is shown. Examples are presented illustrating enhanced visual sensitivity, applicability, and complementary qualitative pulse characterization using SHG FROG.
ABSTRACT
Sensitive, real-time chirp and spectral phase diagnostics along with full field reconstruction of femtosecond laser pulses are performed using a single rapid-scan interferometric autocorrelator. Through the use of phase retrieval error maps, ambiguities in pulse retrievals based on the pulse spectrum and various forms of MOSAIC traces are discussed. We show second-order autocorrelations can introduce significantly different amounts of chirp depending on the implementation. Examples are presented that illustrate the sensitivity and fidelity of the scheme even with low signal-to-noise.
Subject(s)
Algorithms , Equipment Failure Analysis/methods , Interferometry/methods , Lasers , Signal Processing, Computer-Assisted , Statistics as TopicABSTRACT
A method for generation of the modified spectrum autointerferometric correlation that allows single-shot pulse characterization is demonstrated. A sensitive graphical representation of the ultrashort pulse phase quality is introduced that delineates the difference between the presence of temporal and spectral phase distortions. Using these schemes, full-field reconstruction of ultrashort laser pulses is obtained in real time using an efficient iterative technique.
ABSTRACT
The chirp of an ultrashort laser pulse can be extracted with high accuracy from a modified spectrum auto-interferometric correlation waveform by using a new time domain algorithm that allows signal averaging. We display results revealing high sensitivity to chirp even with signal-to-noise levels approaching unity. Correction algorithms have been developed to accommodate signal distortion arising from bandwidth limitations, interferometer misalignment, and nonquadratic detector response.
