Watt-level tunable deep ultraviolet light source by a KBBF prism-coupled device.

Area of Science:

• Nonlinear optics
• Deep ultraviolet (DUV) generation
• Laser technology

Background:

• Generating deep ultraviolet (DUV) light below 200 nm is crucial for various scientific and industrial applications.
• Nonlinear optical crystals are essential for frequency conversion to access these shorter wavelengths.
• Previous methods have faced limitations in achieving high average power in this spectral region.

Purpose of the Study:

• To achieve watt-level average output power in the deep ultraviolet (DUV) region.
• To explore the potential of KBe2BO3F2 crystals for DUV generation.
• To demonstrate tunable DUV output from 185 nm to 200 nm.

Main Methods:

• Utilized a 2.71-mm thick KBe2BO3F2 crystal.
• Employed optical contacting with CaF2 and SiO2 prisms on both sides of the crystal.
• Investigated tunability in the 185-200 nm wavelength range.

Main Results:

• Achieved an average output power of 1.2 W at 200 nm.
• Demonstrated watt-level average power generation in the DUV region.
• Obtained tunable output from 185 nm to 200 nm.
• This represents the highest average power, to our knowledge, for nonlinear crystals below 200 nm.

Conclusions:

• KBe2BO3F2 crystals, when optically contacted with appropriate prisms, are highly effective for DUV generation.
• The demonstrated watt-level power output and tunability open new possibilities for DUV applications.
• This work establishes a new benchmark for high-power DUV generation using nonlinear optical materials.