Diode-pumped continuous wave tunable and graphene Q-switched Tm:LSO lasers.

Area of Science:

• Laser Physics and Photonics
• Materials Science
• Solid-State Lasers

Background:

• Thulium-doped materials are crucial for generating mid-infrared laser light.
• Lithium Silicate (LSO) offers promising host properties for rare-earth ions.
• Investigating Tm:LSO laser performance across different operational modes is essential for its practical application.

Purpose of the Study:

• To characterize the lasing performance of Tm:LSO crystal.
• To explore continuous wave (CW), wavelength-tunable, and passively Q-switched operation.
• To evaluate graphene as a saturable absorber for Q-switching Tm:LSO lasers.

Main Methods:

• Experimental investigation of Tm:LSO laser in CW regime.
• Implementation of a quartz plate for wavelength tuning.
• Utilizing a graphene saturable absorber mirror for passive Q-switching.

Main Results:

• Achieved maximum CW output power of 0.65 W at 2054.9 nm with 21% slope efficiency.
• Demonstrated a broad wavelength tunable range of 145 nm (FWHM 100 nm) using a quartz plate.
• Generated passively Q-switched pulses of 7.8 μs duration at 2030.8 nm with 14.0 μJ pulse energy and 7.6 kHz repetition rate.

Conclusions:

• Tm:LSO crystal exhibits excellent lasing characteristics across multiple operational regimes.
• Graphene is an effective saturable absorber for achieving passively Q-switched Tm:LSO lasers.
• The demonstrated performance highlights Tm:LSO as a viable gain medium for mid-infrared laser applications.