Narrow-linewidth, tunable ultraviolet, Ti:sapphire laser for environmental sensing

Area of Science:

• Optics and Photonics
• Environmental Science
• Laser Technology

Background:

• Titanium:sapphire lasers are crucial for various spectroscopic applications.
• Compact and field-deployable laser systems are needed for environmental monitoring.
• Existing systems may lack the required tunability, linewidth, or efficiency for specific sensing tasks.

Purpose of the Study:

• To develop a compact, narrow-linewidth, etalon-tuned titanium:sapphire laser cavity.
• To design the laser cavity for effective field environmental sensing.
• To characterize the performance of the laser cavity, including its tunable range, conversion efficiency, and linewidth.

Main Methods:

• Utilized an etalon-tuned titanium:sapphire laser cavity design.
• Pumped the laser system using the second harmonic of a kilohertz Nd:YAG laser.
• Measured the fundamental tunable range, conversion efficiency, linewidth, and pulse width.

Main Results:

• Achieved a fundamental tunable range of 690 to 1100 nm.
• Obtained a conversion efficiency of at least 25% for the fundamental and 2-3% for intracavity frequency doubling.
• Demonstrated a narrow linewidth of <0.1 cm⁻¹ and a pulse width of 18 ns.
• Operated with 3.5 to 4 W of 532 nm pump power.

Conclusions:

• The developed laser cavity is suitable for field environmental sensing.
• The system's performance characteristics (tunability, efficiency, linewidth) are advantageous for trace gas measurements.
• Potential applications include laser-induced fluorescence, cavity ringdown spectroscopy, and micropulse lidar.