Giant-chirp oscillators for short-pulse fiber amplifiers

Area of Science:

• * Fiber laser physics
• * Nonlinear optics
• * Ultrafast optics

Background:

• * Conventional chirped-pulse amplification (CPA) systems often involve multiple components like oscillators, stretchers, pulse-pickers, and preamplifiers.
• * Fiber lasers are attractive for generating ultrashort pulses due to their robustness and compactness.

Purpose of the Study:

• * To identify and characterize a new operational regime for fiber lasers.
• * To investigate the potential of this regime for generating large-energy, long-duration, and linearly chirped pulses.
• * To demonstrate the feasibility of using such a laser as a simplified front-end for CPA systems.

Main Methods:

• * Theoretical modeling of dissipative soliton formation in a normal-dispersion fiber laser.
• * Experimental implementation of a fiber laser operating in the identified regime.
• * Characterization of pulse parameters, including duration, chirp, and energy.
• * Amplification of generated pulses and measurement of final pulse characteristics.

Main Results:

• * A new regime of dissipative solitons with large pulse duration (~150 ps) and chirp was identified in a normal-dispersion fiber laser.
• * The developed fiber laser operates at a low repetition rate (3 MHz) and generates high-energy pulses.
• * Amplification of these pulses to 1 microJ energy with a final pulse duration of 670 fs was achieved.

Conclusions:

• * A novel, simplified approach to chirped-pulse amplification using a low-repetition-rate, giant-chirp fiber laser oscillator is demonstrated.
• * This approach can potentially replace conventional multi-component CPA front-ends.
• * The findings highlight the promise of this new laser regime for high-energy pulse generation and amplification.