High Concentration Erbium Implantation of Epitaxially Grown Caf 2 /Si Structures.
- PDF / 518,670 Bytes
- 6 Pages / 414.72 x 648 pts Page_size
- 29 Downloads / 154 Views
ABSTRACT Calcium fluoride thin films grown on silicon substrates by sublimation under ultra high vacuum are well known to be highly efficient hosts for rare earth luminescence properties. For this reason we incorporate erbium by ion implantation in order to form optoelectronic integrated devices. Here we describe the incorporation conditions of erbium in CaFý/Si structures and their luminescence characteristics. The properties of the material have been investigated for implantation doses varying from 4x10 14 to xIO17 at.cm- 2 . The role of oxygen in the charge compensation mechanisms is investigated and it is shown that the maximum emission in erbium at 1.53ltrm occurs for an implanted dose of 2x1016 at.cm- 2 . This corresponds to an Er concentration three orders of magnitude greater than for the case of classical-erbium-doped semiconductors. At this high concentration (up to 15 at.%) the light emission mechanisms are of great theoretical interest. They involve strong Er-Er coupling effects: energy transfer, cross-relaxation phenomena and high conversion efficiencies. These properties make erbium-implanted CaF 2 /Si structures excellent candidates for the production of optically active waveguides. The guiding structure can be formed by high energy implantation to build a buried active region of high refractive index within the CaF 2 thin film.
INTRODUCTION Incorporation of trivalent rare-earth (RE) ions in waveguides holds considerable potential in the field of new processes for optical telecommunication systems. Among REs, erbium is of particular interest because of its 4113/2-4115/2 intra-4f transition with a wavelength of 1.53p.m, coinciding with the low-loss window of standard optical telecommunications silica-based fibers 1. Remarkable progress has been achieved in the development of Er-doped optical fiber amplifiers and lasers 2. Our ultimate goal however, is the production of integrated high gain amplifiers or laser devices on the centimeter scale. Recently, erbium-doped waveguide materials integrated on semiconductor substrates have been investigated and have shown amplification and laser properties 3. 4. The realization of optoelectronic integrated circuits 5 (OEICs) such as active planar optical amplifiers, multiplexers or splitters requires high concentration of luminescent centers in the guiding region; a parameter directly related to amplification performances. Dielectric materials are suitable for the incorporation of high RE concentration with long luminescence lifetimes. Furthermore, they can be grown as thin films on various semiconductor substrates to form true optical-integrated devices 6-11. In a previous study 12,13 we have shown that epitaxial Ca 1 xErxF,,Fx/Si thin films exhibit high intensity 1.53ptm emission at room temperature. In this material, the erbium concentration (x) can be as high as x=16% without quenching of the 1.53[im luminescence. In this paper, we report on the incorporation of erbium by ion implantation in CaF,2 /Si epitaxial thin films.
Er IMPLANTATION AT HIGH DOSES: A NON
Data Loading...
