Route to the minimum pulse duration in normal-dispersion fiber lasers

Area of Science:

• Laser physics
• Nonlinear optics
• Ultrafast optics

Background:

• Understanding factors controlling ultrashort pulse duration is crucial for advancements in laser technology.
• All-normal-dispersion lasers offer unique properties for generating ultrashort optical pulses.

Purpose of the Study:

• To identify and analyze the key factors governing pulse duration in all-normal-dispersion lasers.
• To establish guidelines for minimizing pulse duration and optimizing laser performance.

Main Methods:

• Theoretical analysis of factors influencing pulse duration.
• Numerical simulations of laser dynamics.
• Experimental validation using single-mode fiber at 1-micrometer wavelength.

Main Results:

• Minimal cavity dispersion is essential for achieving the shortest pulse durations.
• Increasing pulse energy, for a fixed dispersion, leads to shorter pulses.
• Spectra become more structured with increasing pulse energy.
• Experimental results with ordinary single-mode fiber produced clean ~80 fs pulses, aligning with simulations.
• Simulations predict the possibility of generating ~30 fs pulses at higher energies.

Conclusions:

• Cavity dispersion and pulse energy are the primary controllable parameters for pulse duration in these lasers.
• Optimizing these parameters can lead to significant reductions in pulse duration.
• The findings provide a pathway for developing lasers capable of generating even shorter pulses.