High-power, narrow-band, high-repetition-rate, 5.9 eV coherent light source using passive optical cavity for...

Area of Science:

• Optics and Photonics
• Laser Physics
• Materials Science

Background:

• High-energy coherent light sources are crucial for advanced spectroscopic techniques.
• Existing sources like synchrotron radiation facilities have limitations in accessibility and cost.
• Developing compact, efficient, and stable laser-based light sources is an ongoing research goal.

Purpose of the Study:

• To demonstrate an efficient scheme for generating a 5.9 eV coherent light source.
• To evaluate the performance characteristics of the generated light source, including power, linewidth, and repetition rate.
• To assess the suitability of this novel light source for high-resolution angle-resolved photoelectron spectroscopy.

Main Methods:

• Utilizing a Ti:sapphire picosecond mode-locked laser as the primary input.
• Employing a passive optical cavity with a BiB(3)O(6) crystal for efficient second-harmonic generation.
• Implementing frequency quadrupling by focusing the second-harmonic light into a β-BaB(2)O(4) crystal.

Main Results:

• Achieved generation of a 5.9 eV coherent light source.
• Obtained an average power of 23 mW with a narrow linewidth of 0.34 meV and a repetition rate of 73 MHz.
• Demonstrated stable operation of the light source for over a week.
• Reported a high second-harmonic generation conversion efficiency of 67%.

Conclusions:

• The developed scheme provides an efficient method for generating a high-quality 5.9 eV coherent light source.
• The characterized performance metrics indicate its potential as a viable alternative to traditional sources for specific applications.
• The light source is well-suited for high-resolution angle-resolved photoelectron spectroscopy, offering advantages in stability and accessibility.