All-solid-state, high-power, deep-UV laser system based on cascaded sum-frequency mixing in CsLiB6O10 crystals

Area of Science:

• Lasers and Photonics
• Nonlinear Optics
• Solid-State Physics

Background:

• Cesium lithium borate (CLBO) crystals are known for their nonlinear optical properties.
• Generating deep-ultraviolet (UV) radiation below 200 nm is challenging.
• All-solid-state laser systems offer advantages in stability and compactness.

Purpose of the Study:

• To demonstrate an efficient all-solid-state deep-UV laser system.
• To achieve high-power UV generation below 200 nm using CLBO crystals.
• To explore the capabilities of CLBO in nonlinear frequency conversion.

Main Methods:

• Utilized cesium lithium borate (CLBO) crystals for nonlinear frequency mixing.
• Employed a 5 kHz Nd:YLF laser and a Ti:sapphire laser.
• Implemented a two-stage nonlinear optical process involving harmonic generation and sum-frequency mixing.

Main Results:

• Generated >3 W of UV radiation at 242 nm by mixing Nd:YLF and Ti:sapphire laser outputs in a CLBO crystal.
• Produced 1.5 W of deep-UV radiation at 196.3 nm by mixing UV output with residual Nd:YLF laser output in a second CLBO crystal.
• Achieved a bandwidth of <200 MHz for both UV outputs, indicating high spectral purity.

Conclusions:

• The study demonstrates the efficient use of CLBO crystals for generating high-power deep-UV radiation.
• The achieved 1.5 W power at 196.3 nm is the highest reported for deep-UV generation below 200 nm in a nonlinear optical crystal.
• The developed all-solid-state laser system offers a promising platform for applications requiring deep-UV light sources.