Flexible picosecond thulium-doped fiber laser using the active mode-locking technique

Area of Science:

• Optics and Photonics
• Laser Physics
• Fiber Lasers

Background:

• Thulium-doped fiber lasers (TDFLs) are crucial for generating light in the 2-micron wavelength range.
• Achieving high repetition rates and tunable pulse widths in TDFLs remains an active area of research.
• Actively mode-locking techniques offer precise control over laser output characteristics.

Purpose of the Study:

• To develop an all-fiber actively mode-locked thulium-doped fiber laser (AML-TDFL).
• To demonstrate flexible picosecond pulse generation at 1980 nm.
• To investigate the tunability of pulse width and repetition rate.

Main Methods:

• Utilized a 10 GHz bandwidth electro-optic intensity modulator (EOM) driven by electrical pulses.
• Employed harmonic mode-locking to achieve high repetition rates.
• Investigated pulse width tuning by adjusting modulation frequency and electrical pulse width.

Main Results:

• Generated flexible picosecond pulses at 1980 nm.
• Achieved a fundamental repetition rate of 21.4 MHz, scalable to 1.498 GHz via 70th order harmonic mode-locking.
• Demonstrated a shortest output pulse width of 38 ps.
• Achieved superior pulse stability with a supermode suppression ratio of up to 48 dB for 1.498 GHz pulses.

Conclusions:

• The developed AML-TDFL provides a stable and flexible platform for generating picosecond pulses at 1980 nm.
• The pulse width tunability offers adaptability for various applications.
• The high repetition rate capability opens possibilities for high-speed optical signal processing.