High sensitization efficiency and energy transfer routes for population inversion at low pump intensity in Er organic complexes for IR amplification

J.X.H., H.Y., H.L. and Y.P.Z. were financially supported by the China Scholarship Council and Queen Mary University of London (QMUL). S.K. was supported by a Proof of Concept grant funded by QMUL and the EPSRC through the Silicon Photonics for Future Systems grant EP/L00044X. J.G. was financially supported by QMUL. I.H. acknowledges financial support from the EU FP7 (Marie Curie-CIG-Grant 303535). Y.Z. acknowledges financial support from the Major State Basic Research Development Program (2013CB922101) and NSFC (21371093). W.P.G. acknowledges financial support from EPSRC (EP/L020114/1 and EP/P007767/1) and from NSFC (61574095

Target dependent femtosecond laser plasma implantation dynamics in enabling silica for high density erbium doping.

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 Er(3+)-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 Er(3+)-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 Er(3+)-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 Er(3+)-ions without clustering, validated by the record high lifetime-density product 0.96 × 10(19) 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 Er(3+) concentration via different target glasses. The increased Er(3+) content in the target glass enhance the refractive index and photoluminescence intensity of the modified silica layer whilst the lifetime and thickness decrease