Ho:CaF(2) solid-state saturable-absorber Q switch for the 2-µm Tm,Cr:Y(3)Al(5)O(12) laser

Area of Science:

• Laser physics
• Solid-state optics
• Materials science

Background:

• Thulium lasers operating around 2 µm are valuable for various applications.
• Developing efficient Q-switching techniques is crucial for enhancing laser performance.
• Solid-state saturable absorbers offer advantages in compactness and robustness.

Purpose of the Study:

• To investigate the efficacy of holmium-doped calcium fluoride (Ho:CaF2) as a saturable absorber.
• To demonstrate its performance in Q-switching a flash-lamp-pumped thulium, chromium: Yttrium aluminum garnet (Tm,Cr:YAG) laser.
• To optimize Q-switching parameters for high-energy pulse generation.

Main Methods:

• Utilized a flash-lamp-pumped Tm,Cr:YAG laser.
• Employed a 1-cm-thick holmium, erbium-doped calcium phosphate (Ho,Er:CaP2) crystal as the saturable absorber.
• Experimented with different output coupler reflectivity values (6.3% and 14.6%).

Main Results:

• Achieved Q-switched laser pulses with a 1-cm-thick Ho(0.5%),Er(5%):CaP2 saturable absorber and a 6.3% output coupler.
• Obtained a single pulse energy of 51 mJ and a duration of 60 ns at 85 J flash-lamp input energy.
• With a 14.6% output coupler, a typical pulse energy of 84 mJ and duration of 82 ns was observed.

Conclusions:

• Holmium-doped calcium fluoride crystals are effective solid-state saturable absorbers for Q-switching Tm:YAG lasers.
• The developed Q-switching method enables high-energy, nanosecond pulse generation at 2.017 µm.
• This technique shows promise for applications requiring pulsed laser sources in this wavelength range.