Mid-infrared ZBLAN fiber supercontinuum source using picosecond diode-pumping at 2 µm

Area of Science:

• Photonics and Optics
• Laser Physics
• Materials Science

Background:

• Supercontinuum generation is crucial for broadband light sources.
• Mid-infrared (mid-IR) sources are essential for spectroscopy and sensing.
• Existing mid-IR sources often face limitations in power, bandwidth, or cost.

Purpose of the Study:

• To demonstrate mid-IR supercontinuum generation pumped by a Thulium fiber laser.
• To achieve broadband generation with high power and spectral flatness in the mid-IR.
• To present a practical and cost-effective route for high-power broadband mid-IR sources.

Main Methods:

• Utilizing picosecond pulses from a Thulium fiber-amplified gain-switched laser diode at 2 µm.
• Employing step-index ZBLAN fiber for supercontinuum generation.
• Characterizing the generated spectrum, bandwidth, power, and spectral flatness.

Main Results:

• Achieved over two octaves of bandwidth (750 - 4000 nm).
• Generated Watt-level average power with spectral flatness < 1.5 dB over a 1300 nm range (2450 - 3750 nm).
• Demonstrated high system stability and potential for power scaling to 10 W.

Conclusions:

• The Thulium laser-pumped system is the first demonstration of its kind for mid-IR supercontinuum generation.
• The developed source offers a practical, versatile, and potentially inexpensive solution for high-power broadband mid-IR radiation.
• This technology opens new avenues for applications requiring high-performance mid-IR light sources.