Continuously adjustable-pulse-width electro-optically Q-switched laser with Nd:YVO₄/Nd:YAG dual crystals

Area of Science:

• Lasers and Photonics
• Materials Science

Background:

• Q-switched lasers are crucial for various applications requiring high peak power.
• Controlling pulse width in solid-state lasers is essential for fine-tuning output characteristics.

Purpose of the Study:

• To develop and demonstrate a continuously adjustable pulse width for an electro-optically Q-switched Nd:YVO4/Nd:YAG laser.
• To establish a theoretical model for dual-crystal pulse width adjustment.

Main Methods:

• Utilized a dual-crystal configuration with Neodymium-doped Yttrium Orthovanadate (Nd:YVO4) and Neodymium-doped Yttrium Aluminum Garnet (Nd:YAG).
• Adjusted pump power on the dual crystals to control the change rate of inverted population number densities.
• Developed a theoretical model to explain the photon density distribution alteration.

Main Results:

• Achieved continuously adjustable pulse widths ranging from 20.8-52.2 ns at 10 kHz and 35.4-93.6 ns at 20 kHz, while maintaining 3 W average power.
• Demonstrated peak power outputs from 5.7-14.4 kW at 10 kHz and 1.6-4.2 kW at 20 kHz.
• Validated the simplicity and stability of the pulse width adjustment method.

Conclusions:

• The dual-crystal approach provides a simple and stable method for continuously tuning pulse width in Q-switched lasers.
• The theoretical model accurately describes the pulse width control mechanism.
• This technique offers flexibility without altering the laser's core mechanical structure.