Liquid excimers: lasing Xe(2) and Kr(2) in liquid argon

Area of Science:

• Physics
• Laser Science
• Materials Science

Background:

• Excimer formation and laser emission in condensed rare gases are crucial for vacuum ultraviolet (VUV) light generation.
• Previous studies have explored VUV lasers, but efficient excitation in liquid media remains an area of active research.

Purpose of the Study:

• To investigate the feasibility of achieving laser action in dilute mixtures of xenon (Xe) and krypton (Kr) within a liquid argon (Ar) matrix.
• To characterize the wavelengths of the emitted VUV laser light.

Main Methods:

• A small cryogenic cell was utilized to maintain liquid argon at low temperatures.
• A pulsed 1-MeV electron beam with a 40-nanosecond pulse duration was employed to excite the gas mixtures.
• Optical detection methods were used to identify and measure the wavelengths of the laser emission.

Main Results:

• Laser emission was successfully excited in dilute mixtures of xenon in liquid argon.
• The excimer Xe(2) produced laser light at a wavelength of 175 nm.
• The excimer Kr(2) generated laser emission at a wavelength of 147 nm.

Conclusions:

• Electron beam pumping is an effective method for achieving VUV laser action in liquid rare gas mixtures.
• This work demonstrates the potential of liquid argon as a gain medium for VUV excimer lasers.
• The observed wavelengths of 175 nm (Xe2) and 147 nm (Kr2) are significant for applications requiring VUV light sources.