Femtosecond Mamyshev oscillator at 920 nm

Area of Science:

• Optics and Photonics
• Laser Physics
• Fiber Optics

Background:

• Development of ultrafast fiber lasers is crucial for various scientific and industrial applications.
• Existing fiber oscillators often face limitations in energy scaling or spectral coverage.
• The 920 nm spectral region is less explored for high-energy femtosecond fiber lasers.

Purpose of the Study:

• To demonstrate the first all-polarization-maintaining (PM) fiber Mamyshev oscillator (MO) operating at 920 nm.
• To achieve high pulse energy and short pulse duration from a fiber-based laser source in this spectral region.
• To establish a new benchmark for femtosecond fiber oscillators in the 920 nm range.

Main Methods:

• Utilized a neodymium-doped fiber with a W-type index profile to suppress unwanted 1064 nm emission.
• Employed a linear cavity incorporating two near-zero dispersion fiber Bragg gratings with Gaussian reflectivity profiles.
• Implemented a grating-pair compressor to achieve pulse compression.

Main Results:

• Successfully demonstrated a self-starting femtosecond all-PM-fiber Mamyshev oscillator at 920 nm.
• Generated pulses with energies up to 10 nJ at a repetition rate of 41 MHz.
• Achieved pulse compression down to 53 fs using a grating-pair compressor.
• Established this as the first MO and highest energy femtosecond fiber oscillator in the 920 nm spectral region.

Conclusions:

• The developed Mamyshev oscillator represents a significant advancement in ultrafast fiber laser technology.
• This work opens new possibilities for applications requiring high-energy femtosecond pulses at 920 nm.
• The demonstrated performance sets a new standard for femtosecond fiber oscillators in this spectral range.