Optical frequency-to-time mapping using a phase-modulated frequency-shifting loop

Area of Science:

• Photonics
• Optical Engineering
• Signal Processing

Background:

• Real-time spectral analysis is crucial for various applications.
• Existing methods may have limitations in speed or resolution.
• Frequency-shifting loops offer potential for advanced optical signal processing.

Purpose of the Study:

• To experimentally demonstrate real-time spectral analysis using a frequency-shifting loop.
• To investigate the frequency-to-time mapping capabilities of the system.
• To analyze the nonlinear characteristics of the spectral mapping.

Main Methods:

• Utilizing a frequency-shifting loop with an electro-optic phase modulator.
• Seeding the loop with single-frequency and polychromatic lasers.
• Analyzing the temporal output for spectral information and mapping fidelity.

Main Results:

• Demonstrated real-time spectral analysis with a frequency-shifting loop.
• Observed pulse doublet emission under integer Talbot conditions with a single-frequency laser.
• Achieved frequency-to-time mapping of polychromatic seed spectra with 400 kHz resolution.
• Confirmed nonlinear mapping due to the phase modulation function.

Conclusions:

• The frequency-shifting loop is a viable platform for real-time spectral analysis.
• The system exhibits nonlinear frequency-to-time mapping, consistent with theoretical predictions.
• Potential for integration into compact systems for diverse applications is discussed.