High-efficiency ultrafast Tm-doped fiber amplifier based on resonant pumping

Area of Science:

• Photonics
• Laser Technology
• Fiber Optics

Background:

• Thulium-doped fiber amplifiers are crucial for generating light in the 2 μm wavelength band.
• Achieving high efficiency and power in ultrafast fiber amplifiers remains a key challenge.

Purpose of the Study:

• To demonstrate a high-efficiency ultrafast thulium-doped fiber amplifier.
• To investigate the effectiveness of resonant pumping techniques for enhancing amplifier performance.

Main Methods:

• Utilized a continuous-wave fiber laser at 1940 nm as the pump source.
• Employed a resonant pumping technique within a thulium-doped fiber amplifier setup.
• Characterized amplifier performance including slope efficiency, output power, repetition rate, pulse duration, peak power, and pulse energy.

Main Results:

• Achieved a slope efficiency of 87% with respect to launched pump power.
• Reached a maximum average output power of 40 W at 53 W launched pump power.
• Generated ultrafast pulses with a repetition rate of 248 MHz, pulse duration of 129 ps, peak power of 1.25 kW, and pulse energy of 161.3 nJ.

Conclusions:

• The resonant pumping technique significantly enhances the efficiency of ultrafast thulium-doped fiber amplifiers.
• This work represents the first demonstration of a high-power, high-efficiency ultrafast fiber laser at 2 μm enabled by resonant pumping.
• The developed amplifier shows great potential for various applications requiring high-energy pulses in the 2 μm band.