Highly efficient passively Q-switched Tm:YAP laser using a Cr:ZnS saturable absorber

Area of Science:

• Laser Physics
• Optoelectronics
• Materials Science

Background:

• Diode-pumped solid-state lasers are crucial for various applications.
• Thulium-doped lasers operating at 2 μm offer unique spectral properties.
• Passively Q-switching enables high peak power generation.

Purpose of the Study:

• To demonstrate a high-power, diode-pumped, passively Q-switched 2 μm Tm:YAP laser.
• To investigate the performance of Cr2+:ZnS saturable absorbers in such systems.
• To achieve high optical efficiencies and pulse energies.

Main Methods:

• Utilized a diode-pumped Tm:YAP laser architecture.
• Employed a Cr2+:ZnS saturable absorber with varying nonsaturated transmission (T0).
• Characterized laser output power, efficiency, pulse energy, peak power, and duration.

Main Results:

• Achieved 10.5 W average output power with a T0=90% saturable absorber.
• Recorded a record 46% optical slope efficiency and 42% overall optical conversion efficiency.
• Generated 0.6 mJ Q-switched pulses with 32 kW peak power, and 1.45 mJ pulses with 138 kW peak power using a T0=80% saturable absorber.

Conclusions:

• The developed Tm:YAP laser system demonstrates high performance for 2 μm generation.
• Cr2+:ZnS saturable absorbers are effective for high-efficiency, high-energy Q-switched operation.
• This work presents a significant advancement in high-power pulsed laser sources.