High on-chip gain spiral Al₂O₃:Er³⁺ waveguide amplifiers

Area of Science:

• Materials Science
• Optoelectronics
• Photonics

Background:

• Integrated photonics requires efficient on-chip optical amplifiers.
• Aluminum oxide (Al2O3) offers a promising host material for rare-earth doping.
• Erbium (Er3+) is a key dopant for optical amplification in the telecommunication C-band.

Purpose of the Study:

• To demonstrate high-gain Al2O3:Er3+ waveguide amplifiers.
• To investigate the performance of these amplifiers for integrated photonic circuits.
• To establish a new benchmark for on-chip net gain in Al2O3:Er3+ systems.

Main Methods:

• Reactive sputtering for Al2O3:Er3+ film deposition.
• Electron beam lithography for waveguide patterning.
• Reactive ion etching for waveguide fabrication.
• Annealing for performance enhancement.
• Bidirectional pumping at 1480 nm for optical gain.

Main Results:

• Achieved over 30 dB small signal net gain at 1532 nm.
• Demonstrated on-chip output powers of 10.2-13.6 dBm.
• Utilized an erbium concentration of 3.9 × 10^20 ions/cm^3.
• Record-breaking on-chip internal net gain for Al2O3:Er3+ waveguide amplifiers.

Conclusions:

• The developed Al2O3:Er3+ waveguide amplifiers represent a significant advancement in integrated photonics.
• The high gain and scalability offer advantages over existing technologies.
• These amplifiers are suitable for various integrated photonic applications requiring efficient signal amplification.