Exceptionally narrow homogeneous linewidth in erbium-doped glasses

Area of Science:

• Materials Science
• Quantum Optics
• Spectroscopy

Background:

• Rare-earth (RE) ions in glasses are crucial for optical applications but their spectral properties are often broadened.
• Spectral diffusion and interactions with two-level systems (TLSs) typically hinder precise measurements of homogeneous linewidths in glasses.
• Previous studies reported broader linewidths for RE ions in glasses at low temperatures.

Purpose of the Study:

• To demonstrate ultra-narrow homogeneous linewidths in rare-earth doped glasses.
• To investigate the potential of these glasses for advanced optical applications like spectral hole burning and holography.
• To understand and minimize spectral diffusion effects in RE-doped glasses.

Main Methods:

• Photon echo measurements were employed to probe the homogeneous linewidth.
• The study utilized erbium (Er3+) doped glasses, specifically Er(3+):2G2S.
• A magnetic field of 5 Tesla was applied to suppress spectral diffusion caused by RE spin-spin interactions and TLSs.

Main Results:

• Homogeneous linewidths as narrow as 287 kHz were achieved at low temperatures (4He temperatures).
• The contribution from TLSs to the linewidth was significantly reduced to 170 T(1.3) kHz under a 5 T magnetic field.
• These linewidths are considerably narrower than previously reported values for glasses in the same temperature range.

Conclusions:

• Rare-earth doped glasses can possess exceptionally narrow homogeneous linewidths, suitable for high-precision optical applications.
• Applying a magnetic field effectively mitigates spectral diffusion, allowing for the study of intrinsic homogeneous linewidths.
• The Er(3+):2G2S glass system shows promise for developing advanced spectral hole burning and spatial-spectral holographic technologies.