An all solid-state UV source based on a frequency quadrupled, passively Q-switched 946 nm laser

Area of Science:

• Optics and Photonics
• Laser Physics
• Materials Science

Background:

• Ultraviolet (UV) light sources are crucial for applications in spectroscopy, photochemistry, and materials processing.
• Efficient generation of UV light often requires nonlinear optical techniques.
• Compact and stable UV sources are highly sought after for specialized applications.

Purpose of the Study:

• To report the development of a compact 236 nm light source.
• To investigate second-harmonic generation (SHG) for UV light production.
• To compare nonlinear crystals for efficient UV generation.

Main Methods:

• Utilized a passively Q-switched 946 nm Neodymium-doped Yttrium Aluminum Garnet (Nd:YAG) laser as the fundamental light source.
• Employed critically phase-matched second-harmonic generation (SHG) in a beta-barium borate (BBO) crystal at room temperature.
• Compared periodically poled potassium titanyl phosphate (KTP) and bismuth borate (BiBO) crystals for 473 nm light generation efficiency and stability.

Main Results:

• Achieved a 236 nm UV light source with 20 mW of average power.
• Demonstrated efficient SHG in a beta-barium borate crystal.
• Evaluated conversion efficiency and stability of periodically poled KTP and BiBO for 473 nm generation.

Conclusions:

• Successfully developed a room-temperature 236 nm light source with significant average power.
• Beta-barium borate crystal is effective for SHG to generate UV light.
• Further comparison of nonlinear crystals like KTP and BiBO is valuable for optimizing UV generation.