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Automation of Mode Locking in a Nonlinear Polarization Rotation Fiber Laser through Output Polarization Measurements
Published on: February 28, 2016
Spectral filtering for mode locking in the normal dispersive regime.
Brandon G Bale1, J Nathan Kutz, Andy Chong
1Department of Applied Mathematics, University of Washington, Seattle, Washington 98195-2420, USA.
Optics Letters
|May 3, 2008
Summary
A new theoretical model explains how to generate ultrashort, high-energy laser pulses using spectral filtering in normal-dispersion cavities. Optimal performance depends on filter bandwidth ratio and output coupler placement.
Area of Science:
- Laser physics
- Nonlinear optics
- Quantum optics
Background:
- Mode-locked lasers generate ultrashort pulses.
- Normal-dispersion lasers present challenges for pulse stability and energy.
- Spectral filtering is a key technique for pulse shaping and control.
Purpose of the Study:
- To develop a theoretical model for ultrashort, high-energy pulse generation in normal-dispersion laser cavities with strong spectral filtering.
- To identify critical physical parameters influencing optimal laser performance.
- To elucidate the role of spectral filtering in maintaining short pulse duration and high energy.
Main Methods:
- Development of a theoretical model based on the physics of ultrashort pulse generation.
- Analysis of the influence of spectral filtering and cavity parameters on pulse characteristics.
- Investigation of the phenomenon in the context of mode-locking with normal dispersion.
Main Results:
- The theoretical model successfully characterizes the physical process of generating ultrashort, high-energy, mode-locked pulses.
- Optimal laser performance is critically dependent on the ratio of filter bandwidth to gain bandwidth.
- Optimal laser performance is also critically dependent on the placement of the output coupler within the laser cavity.
- Strong spectral filtering is essential for maintaining short pulse durations and high pulse energies.
Conclusions:
- The developed theoretical model provides a framework for understanding and optimizing ultrashort pulse generation in normal-dispersion lasers.
- Spectral filtering is a crucial element for achieving high-energy, ultrashort pulses in this laser regime.
- The findings are applicable to mode-locking with normal dispersion generally.
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