Ellipsometry-based study of glass refractive index depth profiles obtained by applying different poling conditions

Area of Science:

• Materials Science
• Solid State Physics
• Glass Science

Background:

• Alkali ions in glass can be mobilized by external stimuli.
• Modification of glass composition affects its optical characteristics, particularly the refractive index.

Purpose of the Study:

• To investigate the effect of electric fields and elevated temperatures on alkali-depleted glass.
• To characterize the resulting changes in refractive index depth profile.
• To correlate optical properties with compositional changes.

Main Methods:

• Application of electric fields and moderate heat to glass samples.
• Spectroscopic ellipsometry for optical property characterization.
• Secondary Ion Mass Spectroscopy (SIMS) for compositional analysis.

Main Results:

• Depletion of alkali from the anode-facing side of the glass was observed.
• A significant variation in the refractive index depth profile was induced.
• The refractive index in the treated region was found to be higher than in untreated glass.
• Ellipsometry-derived refractive index profiles closely matched SIMS concentration profiles.

Conclusions:

• Electric field and thermal treatment effectively modify glass composition by alkali depletion.
• This modification leads to a measurable and enhanced refractive index profile.
• Spectroscopic ellipsometry is a reliable method for characterizing these optical changes, correlating well with compositional data.