Frequency tripled semiconductor disk laser with over 0.5 W ultraviolet output power.

Area of Science:

• Optics and Photonics
• Laser Technology
• Nonlinear Optics

Background:

• Semiconductor disk lasers offer high output power and excellent beam quality.
• Their tunable wavelengths and high intracavity power make them suitable for nonlinear frequency conversion to generate ultraviolet (UV) radiation.

Purpose of the Study:

• To develop a frequency-tripled 327 nm semiconductor disk laser with enhanced output power and wavelength tunability.
• To investigate the use of type-I phase-matched nonlinear crystals for efficient UV generation.

Main Methods:

• Employed a semiconductor disk laser as the fundamental light source.
• Utilized a type-I phase-matched Lithium Triborate (LiB₃O₅ or LBO) crystal for frequency doubling.
• Used a type-I phase-matched Beta Barium Borate (β-BaB₂O₄ or BBO) crystal for frequency tripling, leveraging its larger nonlinear coefficient and a small designed spot size.

Main Results:

• Achieved a record maximum output power of 538 mW for the 327 nm UV laser.
• Reached an optical-to-optical conversion efficiency of approximately 1.14% from pump to UV laser.
• Demonstrated a wavelength tuning range of about 8.6 nm with good power stability (standard deviation of ~0.94%).

Conclusions:

• The developed frequency-tripled semiconductor disk laser represents a significant advancement in UV light sources.
• The use of type-I phase-matched LBO and BBO crystals is highly effective for efficient UV generation.
• This laser system shows promise for applications requiring high-power, tunable UV radiation.