Tabletop spectroscopic ellipsometry for probing optical properties in the extreme ultraviolet

Area of Science:

• Materials Science
• Optics and Photonics
• Spectroscopy

Background:

• Accurate optical-constant determination is crucial for characterizing materials and designing optical systems.
• Extreme-ultraviolet (EUV) spectroscopy presents unique challenges due to the high photon energies and limited source availability.

Purpose of the Study:

• To demonstrate the feasibility of using a tabletop high-harmonic generation (HHG) source for extreme-ultraviolet (EUV) spectroscopic ellipsometry (SE).
• To enable precise determination of complex refractive index (n-ik) in the EUV spectral range.

Main Methods:

• Development of a polarization-resolved EUV spectroscopic ellipsometry system.
• Utilizing a compact tabletop high-harmonic generation (HHG) source for EUV light generation.
• Validation of the system using a known Nb2O5 film and indirect analysis of Mo and Au mirror optical constants.

Main Results:

• Successful implementation of EUV spectroscopic ellipsometry (SE) with a high-harmonic generation (HHG) source.
• Accurate retrieval of the complex refractive index (n-ik) for Nb2O5 film.
• Validated optical constants for molybdenum and gold mirrors within the EUV range.

Conclusions:

• The developed EUV spectroscopic ellipsometry (SE) system offers a compact and versatile platform for precise optical-constant determination.
• This technique is suitable for characterizing materials and optical components in the EUV spectrum.
• The system holds potential for future ultrafast studies in the EUV regime.