Optimization of Low-Loss $AL_{2}O_{3}$ Waveguide Fabrication for Application in Active Integrated Optical Devices

Abstract

In this paper we will present the fabrication and properties of reactively co-sputtered $AL_{2}O_{3}$ layers, being a very promising host material for active integrated optics applications such as rare-earth ion doped laser devices. The process optimization towards a reactive co-sputtering process, which resulted in stable, target condition-independent deposition of $AL_{2}O_{3}$ with high optical quality will be discussed in detail. The loss value of as-deposited optical waveguides sputtered by the optimized process has been measured. The loss in the near infrared wavelength range was 0.3 dB/cm. Furthermore $AL_{2}O_{3}$ material hosts fabricated by sputtering techniques are compatible with Si-based integrated optical technology and allow for uniform deposition over a large substrate area