Dispersion slope equalizer for dispersion shifted fiber using alattice-form programmable optical filter on a planar lightwave circuit

This paper reports an integrated-optic dispersion slope (third-order dispersion) equalizer for dispersion shifted fiber which employs a lattice-form programmable optical filter on a planar lightwave circuit (PLC). This dispersion slope equalizer consists of nine symmetrical interferometers interleaved with eight asymmetrical interferometers. The performance of the equalizer is evaluated numerically. We confirm experimentally that this equalizer is effective in reducing the pulse waveform deterioration caused by the dispersion slope. In addition, the equalizer improves the power penalty of a 200-Gb/s, 100-km, time-division multiplexed optical transmission experiment     

Purification and partial amino acid sequences of the binding protein from Bombyx mori for CryIAa delta-endotoxin of Bacillus thuringiensis

The binding protein for Bacillus thuringiensis delta-endotoxin, CryIAa, from the brush border membrane of the midgut of Bombyx mori was purified by the dot blot method and delta-endotoxin affinity chromatography. The binding protein was purified to 235-fold enrichment from cholic acid extracts of brush border membranes from B. mori midgut by activated CryIAa-affinity chromatography and DEAE ion-exchange chromatography. The purified binding protein showed a single band of 180 kDa by sodium dodecyl sulfate polyacrylamide gel electrophoresis and this band specifically reacted to 125I-labeled CryIAa on Immobilon membrane. The affinity of the binding protein for CryIAa was equivalent to that of the brush border membrane vesicles and solubilized membrane proteins. Partial amino acid sequences of the binding protein showed sequence similarity to the cadherin-like binding protein for CryIAb from Manduca sexta, but not for CryIAc binding protein from M. sexta and Heliothis virescens.     

PLC-type hybrid external cavity laser integrated with front-monitorphotodiode on Si platform

A planar lightwave circuit (PLC)-type hybrid external cavity laser, integrated with a front-monitor photodiode (PD) on Si has been successfully fabricated. Polymer-embedded grooves are incorporated in the cavity to suppress mode hopping, and the optical power of the laser was stabilised from 18 to 56°C with no mode hopping     

400-channel arrayed-waveguide grating with 25 GHz spacing using1.5%-Δ waveguides on 6-inch Si wafer

A large-scale arrayed-waveguide grating with a 400-channel and 25 GHz spacing using 1.5%-Δ silica-based waveguides on a 6-inch Si wafer has been realised. Good demultiplexing properties have been obtained over the full Cand L-band range with an on-chip loss of 3.8 to 6.4 dB and a far-end crosstalk of -30 dB     

Silica-based 8×8 optical matrix switch integrating newswitching units with large fabrication tolerance

An 8×8 optical matrix switch consisting of asymmetric Mach-Zehnder (MZ) interferometer switching units with a waveguide intersection was fabricated using silica-based planar lightwave circuits (PLC's) on a silicon substrate. This switching unit can realize a high extinction ratio and a wide operation wavelength range even if the coupling ratios of the directional couplers (DC's) consisting the switching unit, deviate greatly from the ideal value of 50%. A matrix switch with a DC-coupling ratio of 30% was fabricated to test the validity of the proposed geometry. The average insertion loss was 7.3 dB in the transverse electric (TE) mode and 7.5 dB in the transverse magnetic (TM) mode. The average extinction ratio was 31.2 dB in the TE mode and 31.3 dB in the TM mode. The wavelength range with an extinction ratio greater than 20 dB was over 100 nm     

Low-power consumption silica-based 2×2 thermooptic switchusing trenched silicon substrate

We propose a silica-based 2×2 thermooptic switch using heat insulating grooves and trenches on a Si substrate to reduce electric power consumption. The switching power of a fabricated switch was successfully reduced to 135 mW, less than 1/3 that of a conventional switch. No detrimental effect on optical characteristics was observed: we obtained the insertion loss of 1 dB, the extinction ratio of better than 30 dB and no polarization dependency     

Enhancement of Catalytic Activity on Pd/C and Te–Pd/C During the Oxidative Dehydrogenation of Sodium Lactate to Pyruvate in an Aqueous Phase Under Pressurized Oxygen

The oxidative dehydrogenation of sodium lactate to sodium pyruvate in an aqueous phase proceeded favorably using Pd/C and that doped with Te at 358 K with no adjustment in solution pH under pressurized oxygen, although previous reports had stated that this reaction would not proceed using Pd/C while Pd/C doped with either Pb, Bi or Te showed the activity at atmospheric pressure, 363 K, and a pH of 8.     

Escherichia coli tmRNA (10Sa RNA) in trans-translation

Here we show that Escherichia coli tmRNA (10Sa RNA) has a dual function both as an mRNA and as a tRNA in vitro. The function as a tRNA is prerequisite for the function as an mRNA. These observations strongly support the trans-translation hypothesis.     

Electro-optic switch constructed with a poled silica-basedwaveguide on a Si substrate

2×2 electro-optic switching is demonstrated in an integrated Mach-Zehnder interferometer constructed with thermally poled GeO₂ -doped silica-based channel waveguides on a Si substrate