Wafer-scale inverted gallium phosphide-on-insulator rib waveguides for nonlinear photonics.

We report a gallium phosphide-on-insulator (GaP-OI) photonic platform fabricated by an intermediate-layer bonding process aiming to increase the manufacture scalability in a low-cost manner. This is enabled by the "etch-n-transfer" sequence, which results in inverted rib waveguide structures. The shallow-etched 1.8 µm-wide waveguide has a propagation loss of 23.5 dB/cm at 1550 nm wavelength. Supercontinuum generation based on the self-phase modulation effect is observed when the waveguides are pumped by femtosecond pulses. The nonlinear refractive index of GaP, n2, is extracted to be 1.9 × 10-17 m2/W, demonstrating the great promise of the GaP-OI platform in third-order nonlinear applications.

[A new technique of extracting effective components from Chinese herb and natural plant--microwave assisted extraction, MAE].

The extraction and separation of effective components from Chinese herb and natural plant is one of the most important processes of natural medicine production. Recently, more and more advanced techniques have been used in the field of modern Chinese medicines, for example, microwave-assisted extraction (MAE). Developed on the base of traditional extracting technology using by organic solvents, MAE is of higher extraction rate and efficiency and better extract quality, as well as few investment, simple equipment, wide adaptability, high selectivity, good fidelity and no pollution. This paper mainly reviews the action principle and characteristic of MAE and its application in the extraction of natural products such as flavonoids, glycosides, polysaccharides, terpenoids and essence. Otherwise, the developing foreground of MAE is also prospected here.