Temporal resolution limits of time-to-frequency transformations

Area of Science:

• Optics and Photonics
• Nonlinear Optics

Background:

• Time-to-frequency converters map light pulse intensity to its spectrum.
• Two primary architectures exist: dispersive line with phase modulator, and spectral Fraunhofer regime time lens.

Purpose of the Study:

• Compare the equivalence of two time-to-frequency converter architectures.
• Analyze their performance based on pulse coherence and spectral conditions.
• Investigate subpicosecond resolution capabilities.

Main Methods:

• Theoretical analysis of two distinct time-to-frequency converter designs.
• Examination of spectral Fraunhofer regime conditions.
• Evaluation of converter performance with varying pulse coherence and dispersion.

Main Results:

• The two architectures are not generally equivalent.
• Incoherent mapping is achieved with the dispersive line.
• The time lens approach's output depends on pulse coherence and residual dispersion.
• Subpicosecond resolution is attainable outside the spectral Fraunhofer limit.

Conclusions:

• Converter architecture choice critically impacts time-to-frequency mapping.
• Understanding coherence and dispersion is key for optimal converter design.
• These converters show potential for advanced optical pulse characterization.