Simple high-efficiency TEM(00) diode-laser-pumped Q-switched laser.

Area of Science:

• Laser physics and engineering
• Materials science for laser gain media

Background:

• Diode-laser-pumped solid-state lasers offer advantages in efficiency and compactness.
• Q-switching is a technique to achieve high peak power laser pulses.
• Nd:YAG lasers are widely used in various scientific and industrial applications.

Purpose of the Study:

• To develop a simple and efficient diode-laser-pumped Q-switched Nd:YAG laser.
• To demonstrate high-energy, short-pulse generation with excellent beam quality.
• To investigate the potential for efficient harmonic generation.

Main Methods:

• Utilized a zigzag slab geometry for the Nd:YAG gain medium.
• Employed side pumping with a single high-power quasi-continuous-wave diode bar.
• Operated the laser in a Q-switched mode to produce nanosecond pulses.
• Measured laser output characteristics, including pulse energy, pulse duration, repetition rate, and beam quality (TEM00).
• Evaluated second and fourth harmonic generation efficiencies.

Main Results:

• Achieved 2.25 mJ, TEM00, 4-ns pulses at up to 90 Hz with only 20 mJ of pump power.
• Demonstrated long-pulse and Q-switched slope efficiencies of 28% and 19%, respectively.
• Obtained second-harmonic generation efficiency greater than 50% and fourth-harmonic generation efficiency greater than 20% at 1064 nm.
• Performance approached that of longitudinal pumping configurations.

Conclusions:

• The developed diode-laser-pumped Q-switched Nd:YAG laser is highly efficient and simple.
• The zigzag slab geometry and side-pumping scheme are effective for high-power laser operation.
• The laser system shows significant potential for applications requiring high peak power and efficient frequency conversion.