We report an athermal InP (110) optical modulator with a simple planar n-SI-n heterostructure. A symmetrical push-pull operation provides a high-extinction ratio of >25 dB over the entire C-band and ...zero-chirp modulation. A Mach-Zehnder optical modulator (MZM) exhibits a 3 dB-EO bandwidth of 30 GHz and 40-Gb/s NRZ high-speed modulation with wavelength and temperature insensitive operation. We also successfully demonstrate an MZM integrated twin-IQ modulator that exhibits 56-Gb/s × 2 athermal QPSK modulation at constant drive and bias voltages.
A reduction in the intensity deviation of a nine-channel optical frequency comb block (OFCB) is demonstrated, by adopting an asymmetric differential drive method for an InP-based dual drive ...Mach-Zehnder modulator. The generation of a tailored OFCB with an intensity deviation of less than 0.8dB is confirmed by using the modulator.
We present a traveling-wave-electrode InP-based Mach-Zehnder (MZ) modulator that employs an n-p-i-n waveguide structure. The structure provides low electrical and optical propagation losses, which ...enables the modulator to operate at a high baud rate with a low driving voltage and a low optical insertion loss. We developed a compact 40-Gb/s differential phase shift keying (DPSK) tunable wavelength transmitter module, which incorporates a full C-band tunable laser and the MZ modulator in one package. The RF driving voltage for the MZ modulator is 3 V pp in a push-pull drive configuration. Using the same design for the MZ modulator, we also developed a differential quadrature phase shift keying (DQPSK) modulator or optical IQ modulator, and acheived 80-Gb/s DQPSK modulation. Furthermore, we fabricated a compact dual-polarization (DP) QPSK modulator by using the hybrid integration of an InP twin-IQ modulator and a planar lightwave circuit (PLC) polarization multiplexing circuit (PMC). We successfully demonstrated 112-Gbit/s DP-QPSK signal generation.
Dinotefuran (MTI-446: (RS)-1-methyl-2-nitro-3-(tetrahydro-3-furylmethyl)guanidine) is a new neonicotinoid commercialized by Mitsui Chemicals. Research led to this novel neonicotinoid by the removal ...of the chloropyridine or chlorothiazole ring that had been considered as indispensable for neonicotinoides. The research advanced as follows; (1) selection of acetylcholine for the lead compound, (2) recognition of the insecticidal advantages of 3-methoxypropyl compounds, (3) synthesis of (±)-tetrahydro-3-furylmethyl compounds by cyclization of the 3-methoxypropyl moiety. It resulted in dinotefuran which has a (±)-tetrahydro-3-furylmethyl moiety instead of a halogenated aromatic heterocyclic ring, and belongs to the third-generation neonicotinoids (sub-class: furanicotinyl compounds).
We report novel high-bandwidth InP-based Mach-Zehnder modulator and in-phase/quadrature (IQ) modulators that we realized by combining an n-i-p-n heterostructure and a capacitively loaded traveling ...wave electrode. The extremely low electrical and optical loss structure enhances the 3-dB electro-optic bandwidth of over 67 GHz without degrading other properties such as driving voltage and optical loss. The modulator also exhibits a static extinction ratio of over 24 dB with a Vπ of less than 1.5 V for the entire C-band. Furthermore, we demonstrate the first 120-Gbaud rate IQ modulation without optical pre equalization, and 100-Gb/s non-return-to-zero on-off keying modulation with a dynamic extinction ratio of over 10 dB.
For the purpose of development of the laser technique in veterinary medicine, the new bowel welding method using a diode laser were devised. A special intestinal clamp was developed for these ...studies, and it was named laser welding intestinal clamp (LW clamp). In fundamental researches, laser welding of bowel in dogs and cats was confirmed to be possible using the LW clamp and the contact probes under a diode laser. Therefore, we expected that this method is applicable to clinical cases. Laser bowel anastomoses were performed for cats with megacolon and toy-breed dogs with severe bowel obstruction. As short- and long-term clinical results, any severe postoperative complications were not found, and all cases revealed favorable recovery.
For the purpose of development of the laser technique in veterinary medicine, the new bowel welding method using a diode laser were devised. A special intestinal clamp was developed for these ...studies, and it was named laser welding intestinal clamp (LW clamp). In fundamental researches, laser welding of bowel in dogs and cats was confirmed to be possible using the LW clamp and the contact probes under a diode laser. Therefore, we expected that this method is applicable to clinical cases. Laser bowel anastomoses were performed for cats with megacolon and toy-breed dogs with severe bowel obstruction. As short- and long-term clinical results, any severe postoperative complications were not found, and all patients revealed favorable recovery.
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