Atomic layer engineering of Er-ion distribution in highly doped Er:Al2O3 for photoluminescence enhancement

Research output: Contribution to journalArticleScientificpeer-review

Researchers

Research units

  • University of Arizona
  • University of Eastern Finland

Abstract

For the past decade, erbium-doped integrated waveguide amplifiers and lasers have shown excellent potential for on-chip amplification and generation of light at the important telecommunication wavelength regime. However, Er-based integrated devices can only provide small gain per unit length due to the severe energy-transfer between the Er-ions at high concentration levels. Therefore, active ion concentrations have been limited to <1% levels in these devices for optimal performance. Here, we show an efficient and practical way of fabricating Er-doped Al2O3 with Er-concentration as high as ∼3.5% before concentration quenching starts to limit the C-band emission in our material. The Er-doped Al2O3 was fabricated by engineering the distribution of the Er-ions in Al2O3 with the atomic layer deposition (ALD) technique. By choosing a proper precursor for the fabrication of Er2O3, the steric hindrance effect was utilized to increase the distance between the Er-ions in the lateral direction. In the vertical direction, the distance was controlled by introducing subsequent Al2O3 layers between Er2O3 layers. This atomic scale control of the Er-ion distribution allows us to enhance the photoluminescence of our Er:Al2O3 material by up to 16 times stronger when compared to the case where the Er-concentration is ∼0.6%. In addition, long lifetime of approximately 5 ms is preserved in the Er-ions even at such high concentration levels. Thus, our optimized ALD process shows very promising potential for the deposition of optical gain media for integrated photonics structures.

Details

Original languageEnglish
Pages (from-to)2040–2048
Number of pages9
JournalACS Photonics
Volume3
Issue number11
Publication statusPublished - 16 Nov 2016
MoE publication typeA1 Journal article-refereed

    Research areas

  • erbium, rare-earth ions, atomic layer deposition, photoluminescence, optical amplifier, integrated photonics

ID: 9516906