Two-mJ level, high-energy all-passive KGW/Tm:YLF Raman laser

Area of Science:

• Laser Physics
• Nonlinear Optics
• Materials Science

Background:

• Development of efficient lasers in the 2-micrometer spectral range is crucial for various applications.
• Stimulated Raman scattering (SRS) offers a pathway to generate new wavelengths from existing laser sources.
• All-passive configurations are desirable for simplicity and robustness.

Purpose of the Study:

• To develop and characterize an all-passive external cavity KGW Raman laser operating in the 2-micrometer spectral range.
• To achieve record-breaking energy per pulse and conversion efficiency for SRS in this spectral region.
• To investigate the performance of KGW crystals in a passive Raman laser setup.

Main Methods:

• Utilized a Tm:YLF laser operating at 1879.5 nm as the pump source.
• Employed an all-passive external cavity design incorporating a KGW (KY3(WO4)2) crystal.
• Investigated stimulated Raman scattering to generate output at longer wavelengths.

Main Results:

• The KGW Raman laser successfully emitted two lines at 2197 nm and 2263 nm.
• Maximum energy outputs of 1.86 mJ and 2.08 mJ were achieved for the two lines, respectively.
• Maximum conversion efficiencies of 40% and 45.3% were recorded, setting new records for this configuration.

Conclusions:

• The developed all-passive KGW Raman laser represents a significant advancement in 2-micrometer wavelength generation.
• The achieved performance surpasses previous records for energy per pulse and conversion efficiency in passive Raman lasers in the 2-micrometer range.
• This work highlights the potential of KGW crystals for high-performance SRS applications.