Ultrashort pulse characterisation with SHG collinear-FROG.

Area of Science:

• Optics and Photonics
• Ultrafast Laser Science
• Spectroscopy

Background:

• Traditional non-collinear FROG (frequency-resolved optical gating) is complex.
• Accurate laser pulse characterization is crucial for ultrafast science.
• Existing methods can be cumbersome and require specialized setups.

Purpose of the Study:

• To outline criteria for fast and accurate collinear FROG (CFROG) trace acquisition.
• To demonstrate CFROG as a versatile alternative to non-collinear FROG.
• To enable the use of CFROG in experiments with imposed collinear geometry.

Main Methods:

• Development of criteria for rapid and precise CFROG trace acquisition.
• Data processing to transform CFROG traces into traditional non-collinear FROG traces.
• Numerical and experimental validation of the CFROG technique.

Main Results:

• Established criteria for efficient and accurate CFROG trace collection.
• Demonstrated successful transformation of CFROG data for conventional retrieval algorithms.
• Achieved excellent results in both numerical simulations and experimental tests.

Conclusions:

• CFROG offers a simpler, more versatile geometry compared to non-collinear FROG.
• The data processing method allows leveraging existing SHG-FROG retrieval algorithms.
• CFROG is a practical and attractive alternative for laser pulse characterization, especially in collinear setups.