Polarization-independent pulse retrieval based on frequency resolved optical switching

Area of Science:

• Optics and Photonics
• Ultrafast Laser Science
• Nonlinear Optics

Background:

• Characterizing ultrafast optical pulses is crucial for understanding light-matter interactions.
• Existing methods can be limited by pulse polarization states.
• Frequency Resolved Optical Switching (FROSt) offers a potential solution.

Purpose of the Study:

• To experimentally validate the polarization independence of the FROSt technique.
• To demonstrate FROSt's capability in characterizing multiple co-propagating pulses with orthogonal polarizations.
• To showcase FROSt's application in analyzing nonlinear optical processes involving polarization changes.

Main Methods:

• Experimental demonstration of FROSt with varying pulse polarizations.
• Characterization of two or three co-propagating pulses with orthogonal linear polarizations.
• Application of FROSt to study type-I second harmonic generation (SHG).

Main Results:

• The FROSt method's independence from the characterized pulse's polarization direction was experimentally confirmed.
• Simultaneous retrieval of temporal intensity, phase profiles, and group delay for orthogonally polarized pulses was achieved.
• Depleted fundamental and generated second-harmonic pulses in type-I SHG were successfully characterized.

Conclusions:

• The FROSt technique is a robust and versatile tool for ultrafast optical pulse characterization, irrespective of polarization.
• FROSt enables comprehensive analysis of nonlinear optical processes, including those with changing polarization states.
• This method provides valuable insights into both temporal and spectral dynamics of light-matter interactions.