2.07-microm cw diode-laser-pumped Tm, Ho:YLiF(4) room-temperature laser

Area of Science:

• Laser physics
• Solid-state lasers
• Infrared optics

Background:

• Thulium-sensitized holmium-doped lasers (Tm:Ho:YLF) are efficient sources of mid-infrared radiation.
• Optimizing Tm:Ho:YLF laser performance is crucial for applications requiring specific wavelengths and high power.

Purpose of the Study:

• To investigate the continuous-wave (CW) and Q-switched performance of a Tm-sensitized Ho:YLF laser.
• To evaluate the impact of crystal length and temperature on laser output characteristics.

Main Methods:

• Longitudinal pumping of a Tm-sensitized Ho:YLF crystal using diode-laser arrays.
• Characterization of CW laser output power, slope efficiency, and lasing threshold at room temperature (300 K).
• Evaluation of laser performance at cryogenic temperature (77 K) and demonstration of Q-switched operation.

Main Results:

• Continuous-wave operation achieved at 2.07 micrometers with a 2-mm-long Tm:Ho:YLF crystal at 300 K.
• Laser output power of 26 mW at 300 K with 30% slope efficiency and a 108 mW threshold.
• Maximum output power of 187 mW at 77 K with 67% slope efficiency.
• Preliminary Q-switching demonstrated 165 microJ pulse energy at 100 Hz repetition rate.

Conclusions:

• The Tm-sensitized Ho:YLF laser system exhibits efficient CW and pulsed operation at 2.07 micrometers.
• Performance is significantly enhanced at cryogenic temperatures, indicating potential for high-power applications.
• The demonstrated Q-switched capabilities open avenues for pulsed laser applications in the mid-infrared spectrum.