Chemical dissimilarity of tellurium oxide with silica glass increases phase separation and crystallization tendency when mixed and melted for making a glass. We report a novel technique for incorporating an Er3+-doped tellurite glass composition into silica substrates through a femtosecond (fs) laser generated plasma assisted process. The engineered material consequently exhibits the spectroscopic properties of Er3+-ions, which are unachievable in pure silica and implies this as an ideal material for integrated photonics platforms. Formation of a well-defined metastable and homogeneous glass structure with Er3+-ions in a silica network, modified with tellurite has been characterized using high-resolution cross-sectional transmission electron microscopy (HRTEM). The chemical and structural analyses using HRTEM, Rutherford backscattering spectrometry (RBS) and laser excitation techniques, confirm that such fs-laser plasma implanted glasses may be engineered for significantly higher concentration of Er3+-ions without clustering, validated by the record high lifetime-density product 0.96 × 1019 s.cm−3. Characterization of planar optical layers and photoluminescence emission spectra were undertaken to determine their thickness, refractive indices and photoluminescence properties, as a function of Er3+ concentration via different target glasses. The increased Er3+ content in the target glass enhance the refractive index and photoluminescence intensity of the modified silica layer whilst the lifetime and thickness decrease.

Abstract:The limited solubility of rare-earths in silica hampers the development of loss-compensated photonic integrated circuits. We report a novel method using femtosecond laser plasma assisted hybrid material integration of rare-earth-doped tellurite with silica, achieving high doping concentration of Er 3+

An ultrafast laser plasma doping (ULPD) technique is used to high concentration doping of erbium ions into silica-onsilicon substrate. The method uses femtosecond laser to ablate material from TeO2-ZnO-Na2O-Er2O3 (Er-TZN) target glass. The generated plasma modifies the silica network, producing high index contrast optical layer suited to the production of on-chip integrated optical circuits. Cross-sectional analysis using scanning electron microscope with energy dispersive x-ray spectroscopy revealed homogenous intermixing of the host silica with Er-TZN, which is unique to ULPD. The highly doped layer exhibits spectroscopic characteristics of erbium with photoluminescence lifetimes ranging from 10.79 ms to 14.07 ms.

The properties of Er 3+-doped gallium lanthanum sulphide thin films prepared on a silicon substrate by femtosecond pulsed laser deposition were studied as a function of process temperature. The films were characterised using transition electron microscopy imaging, X-ray diffractometry, Raman spectroscopy, fluorescence spectroscopy, and UV-Vis-NIR spectroscopy. The results show that by increasing the substrate temperature, the deposited layer thickness increases and the crystallinity of the films changes. The room temperature photoluminescence and lifetimes of the 4 I 13/2 → 4 I 15/2 transition of Er 3+ are reported in the paper.

No abstract