Higher order mode supercontinuum generation in tantalum pentoxide (Ta2O5) channel waveguide

On-chip Er-doped Ta2O5 waveguide amplifiers with a high internal net gain

We designed and fabricated a double-layered structure Er3+:Ta2O5 waveguide and investigated its optical amplification performance in C band. The pump laser threshold for zero gain at 1533 nm was 2.5 mW, and the internal net gain was ∼4.63 dB/cm for a lunched pump power of 36.1 mW at 980 nm and signal input power of -30.0 dBm (1 µW). The relationship between the internal gain and the signal input power was also investigated, and a large internal net gain of 10.58 dB/cm was achieved at a signal input power of ∼-47.1 dBm. The results confirm the potentials of the use of Ta2O5 as a host material for optical waveguide amplification.

Cluster-Glass for Low-Cost White-Light Emission

The development of efficient and high-brilliance white-light sources is an essential contribution to innovative emission technologies. Materials exhibiting strong nonlinear optical properties, in particular second-harmonic generation (SHG) or white-light generation (WLG), have therefore been investigated with great activity in recent times. While many new approaches have been reported until now, the processability of the compounds remains a challenge. Here, a new class of materials, denoted as "cluster-glass", which do not only show superior white-light emission properties upon irradiation by an inexpensive continuous-wave infrared laser diode, but can be easily accommodated in size and shape by formation of robust glassy solids, is introduced. The cluster-glass materials are fabricated by mild heating from crystalline powders of adamantane-type clusters exhibiting a quaternary, inorganic-organic hybrid cluster core [(PhSi)(CH₂ )₃ (PhSn)E₃ ] (E  =  S, Se, Te). The process is fully reversible and preserves the integrity of the clusters in the glass, as proven by solution spectroscopy and recrystallization. Theoretical studies corroborate the importance of the quaternary nature of the cluster cores for the observed structural and optical phenomena. Thanks to these findings, high-brilliance white-light sources can be synthesized in form of stable, robust glass of any shape, which ultimately renders them suitable for everyday's applications.