Bright compact ultrabroadband source by orthogonal laser-sustained plasma

Area of Science:

• Physics
• Optics
• Materials Science

Background:

• Laser-sustained plasma (LSP) sources offer high brightness and broad spectral coverage, valuable for scientific and industrial uses.
• Low conversion efficiency is a key limitation, hindering compactness and widespread adoption of current LSP broadband light sources.

Purpose of the Study:

• To propose and demonstrate an innovative orthogonal LSP design to overcome the conversion efficiency limitation.
• To achieve a compact, high-efficiency broadband light source with enhanced UV spectral radiance.

Main Methods:

• Developed an orthogonal LSP configuration to mitigate the negative lensing effect on laser power density.
• Utilized a >100 W pump laser to drive the plasma source.
• Characterized the spectral radiance and conversion efficiency of the generated broadband emission.

Main Results:

• Achieved a compact broadband source (250-1650 nm) with UV spectral radiance exceeding 210 W/cm²/sr.
• Demonstrated the highest conversion efficiency to date for such sources, with negligible thermal loss.
• Improved contrast-to-noise ratio (CNR) by 4 dB in spectral single-pixel imaging using the novel source.

Conclusions:

• The orthogonal LSP design effectively eliminates detrimental lensing effects, enhancing laser power density.
• The developed source offers superior conversion efficiency and brightness, crucial for applications like high-speed inspection and spectroscopy.
• This work establishes a quantitative link between pumping optics and plasma absorption, paving the way for advanced light source development.