Greater than 50% inversion in Erbium doped Chalcogenide waveguides

Area of Science:

• Materials Science
• Optoelectronics
• Photonics

Background:

• Chalcogenide glasses are promising for optical applications.
• Erbium doping enables light emission at telecommunication wavelengths.
• Developing efficient Er-doped waveguides is crucial for integrated optics.

Purpose of the Study:

• To fabricate and characterize Erbium-doped Germanium-Gallium-Selenide (Ge-Ga-Se) films and waveguides.
• To investigate the optical properties of these materials for potential amplifier applications.
• To assess the population inversion achieved in the Erbium ions.

Main Methods:

• Co-thermal evaporation for film deposition.
• Plasma etching for waveguide patterning.
• Photoluminescence spectroscopy for optical characterization.
• Lifetime measurements to determine emission properties.

Main Results:

• Strong photoluminescence at 1.54 µm was observed with a 1490 nm excitation source.
• An intrinsic lifetime of 1 ms was measured for the Er-doped films.
• Erbium population inversion reached up to 50%, nearing the theoretical maximum.
• Upconversion pumped photoinduced absorption prevented optical gain.

Conclusions:

• Er-doped Ge-Ga-Se films exhibit excellent photoluminescent properties.
• The achieved population inversion is a significant step towards waveguide amplifiers.
• Further optimization is needed to overcome parasitic absorption and achieve net gain.