Cr(4+):YAG double-clad crystal fiber laser

Area of Science:

• Materials Science
• Optoelectronics
• Laser Physics

Background:

• Development of efficient solid-state lasers is crucial for various scientific and industrial applications.
• Chromium-doped lasers offer unique tunable properties but often require specific operating conditions.
• Crystal fiber lasers present advantages in beam quality and power handling.

Purpose of the Study:

• To demonstrate the first room-temperature, continuous-wave Cr(4+):YAG double-clad crystal fiber laser.
• To investigate the performance characteristics, including threshold and efficiency, of this novel laser system.
• To validate experimental results with numerical simulations.

Main Methods:

• Growth of Cr(4+):YAG crystal fibers using the codrawing laser heated pedestal growth (LHPG) method.
• Fabrication of a double-clad crystal fiber laser.
• Characterization of laser performance under continuous-wave operation at room temperature.

Main Results:

• Achieved room-temperature, continuous-wave lasing of a Cr(4+):YAG double-clad crystal fiber.
• Demonstrated a threshold below 100 mW, a fourfold reduction compared to previous Cr(4+)-doped lasers.
• Obtained a slope efficiency of 6.9%, consistent with numerical simulations.
• Attributed low-threshold lasing to small core diameter, low propagation loss (0.08 dB/cm), and high core crystallinity.

Conclusions:

• The codrawing LHPG method is effective for producing high-quality Cr(4+):YAG crystal fibers for laser applications.
• The developed double-clad crystal fiber laser exhibits superior low-threshold performance at room temperature.
• This work paves the way for practical, efficient, and compact chromium-doped fiber lasers.