Efficient continuous-wave radiatively cooled cr(4+):forsterite lasers at room temperature

Area of Science:

• Laser physics
• Solid-state laser technology
• Materials science

Background:

• Continuous-wave (cw) Cr(4+):forsterite lasers face thermal loading challenges at elevated temperatures.
• Efficient laser operation is crucial for various scientific and industrial applications.

Purpose of the Study:

• To investigate methods for reducing thermal loading in cw Cr(4+):forsterite lasers.
• To achieve high output power at room temperature without compromising laser performance.
• To explore the impact of crystal properties on thermal management.

Main Methods:

• Experimental investigation of a cw Cr(4+):forsterite laser.
• Utilizing a crystal with a low differential absorption coefficient (0.57 cm(-1)).
• Employing an efficient radiative cooling technique.

Main Results:

• Achieved 900 mW of cw output power at 1.26 µm with only 4.5 W of absorbed pump power at 1.06 µm.
• Observed a crystal boundary temperature of 15°C with no power fading.
• Attained an absorbed power slope efficiency of 29.5%, the highest reported for this laser type pumped by Nd:YAG around room temperature.
• Demonstrated the benefit of low differential absorption coefficient crystals compared to higher absorption ones (1.78 cm(-1)).

Conclusions:

• A low differential absorption coefficient Cr(4+):forsterite crystal combined with radiative cooling effectively mitigates thermal loading.
• This approach enables high-power cw operation of Cr(4+):forsterite lasers near room temperature.
• The study highlights a significant advancement in the performance of Cr(4+):forsterite lasers.