We demonstrate deformation-suppressed optical deposition of graphene onto an optical fiber by forming a graphene/polyvinyl acetate (PVAc) composite for ultrafast nonlinear photonics. With pure graphene, its nonlinear operation threshold is elevated by the optical deposition that cannot guarantee the intact two-dimensional nanoshape of graphene. The role of PVAc that provides immunity to graphene against deleterious degradation of morphology and optical nonlinearity is elucidated via electron microscope analysis, Raman characterization, and realizing passive mode-locking operation of fiber lasers. Resultant center wavelength, spectral width, and repetition rate of the laser pulses are 1572.6 nm, 0.6 nm, and 91.5 MHz, respectively.

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SUMMARYA supercritical carbon dioxide power cycle has been focused as a promising power cycle because of its compactness, a high efficiency, and a wide applicability. A 10-kWe-class simple unrecuperated supercritical carbon dioxide Brayton experimental loop including a turbo-alternator-compressor unit using a centrifugal compressor and a radial turbine was developed. A shrouded type of a compressor impeller and a turbine wheel with labyrinth seals were designed to overcome thrust balancing problems of the high-pressure fluid turbomachinery. In addition, this type has no issues on the thermal growth collision failure and clearance loss between a shroud and a wheel. Preliminary operation at 30,000 rpm, turbine inlet temperature of 83°C, and pressure of 8500 kPa was successful. It is founded that all states of the cycle existed in the supercritical region.

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