Zeolite-templated carbon is a promising candidate as an electrode material for constructing an electric double layer capacitor with both high-power and high-energy densities, due to its three-dimensionally arrayed and mutually connected 1.2-nm nanopores. This carbon exhibits both very high gravimetric (140-190 F g(-1)) and volumetric (75-83 F cm(-3)) capacitances in an organic electrolyte solution. Moreover, such a high capacitance can be well retained even at a very high current up to 20 A g(-1). This extraordinary high performance is attributed to the unique pore structure.

An ordered microporous carbon, which was prepared with zeolite as a template, was used as a model material to understand the ion storage/transfer behavior in electrical double-layer capacitor (EDLC). Several types of such zeolite-templated carbons (ZTCs) with different structures (framework regularity, particle size and pore diameter) were prepared and their EDLC performances were evaluated in an organic electrolyte solution (1 M Et(4)NBF(4)/propylene carbonate). Moreover, a simple method to evaluate a degree of wettability of microporous carbon with propylene carbonate was developed. It was found that the capacitance was almost proportional to the surface area and this linearity was retained even for the carbons with very high surface areas (>2000 m(2) g(-1)). It has often been pointed out that thin pore walls limit capacitance and this usually gives rise to the deviation from linearity, but such a limitation was not observed in ZTCs, despite their very thin pore walls (a single graphene, ca. 0.34 nm). The present study clearly indicates that three-dimensionally connected and regularly arranged micropores were very effective at reducing ion-transfer resistance. Despite relatively small pore diameter ZTCs (ca. 1.2 nm), their power density remained almost unchanged even though the particle size was increased up to several microns. However, when the pore diameter became smaller than 1.2 nm, the power density was decreased due to the difficulty of smooth ion-transfer in such small micropores.

Abstract:We demonstrate an optical amplifier based on an erbium doped holey fiber (EDHF) with a small core. Owing to the high NA, which is readily achievable using holey fiber technology, and the tight physical confinement of the erbium ions, we show that it is possible to achieve an internal gain efficiency of >8.5dB/mW using an aluminosilicate based glass within the core. The dependence of the gain and noise figure performance with respect to fiber length and wavelength are experimentally characterized.

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Abstract-We experimentally demonstrate a novel pulse compression scheme using dispersion decreasing fiber (DDF)-based distributed Raman amplification. We adiabatically compress 10-GHz 13-ps seed pulses generated using a commercially available electroabsorption modulator into high-quality 1.3-ps pulses in a 20-km DDF-based diode-pumped Raman amplifier. The usual DDF adiabatic soliton compression process is assisted by the distributed Raman gain along the fiber and by control of the input pulse chirp. Both wavelength tunability of about 30 nm and pulse-duration tunability from 1 to 5 ps are also demonstrated.