Kosaka, H.
Kiselev, A.A.
Baron, F.A.
Kim, Ki Wook
Yablonovitch, E.
An entanglement-preserving photodetector converts photon polarisation to electron spin. Up and down spin must respond equally to oppositely polarised photons, creating a requirement for degenerate spin energies, g(e) similar or equal to 0, for electrons. The authors present a plot of g(e) factor against lattice constant, analogous to bandgap against lattice constant. that can be used for g factor engineering of III-V alloys and quantum wells.
Kosaka, H.
Omori, M.
Murata, T.
Iidaka, T.
Yamada, H.
Okada, T.
Takahashi, T.
Sadato, N.
et. al.
Human lesion or neuroimaging studies suggest that amygdala is involved in facial emotion recognition. Although impairments in recognition of facial and/or emotional expression have been reported in schizophrenia, there are few neuroimaging studies that have examined differential brain activation during facial recognition between patients with schizophrenia and normal controls. To investigate amygdala responses during facial recognition in schizophrenia, we conducted a functional magnetic resonance imaging (fMRI) study with 12 right-handed medicated patients with schizophrenia and 12 age- and sex-matched healthy controls. The experiment task was a type of emotional intensity judgment task. During the task period, subjects were asked to view happy (or angry/disgusting/sad) and neutral faces simultaneously presented every 3 s and to judge which face was more emotional (positive or negative face discrimination). Imaging data were investigated in voxel-by-voxel basis for single-group analysis and for between-group analysis according to the random effect model using Statistical Parametric Mapping (SPM). No significant difference in task accuracy was found between the schizophrenic and control groups. Positive face discrimination activated the bilateral amygdalae of both controls and schizophrenics, with more prominent activation of the right amygdala shown in the schizophrenic group. Negative face discrimination activated the bilateral amygdalae in the schizophrenic group whereas the right amygdala alone in the control group, although no significant group difference was found. Exaggerated amygdala activation during emotional intensity judgment found in the schizophrenic patients may reflect impaired gating of sensory input containing emotion.
We have developed plastic-molded receptacle-lope vertical-cavity surface-emitting laser (VCSEL)-array modules directly push/pull connectable with the one-dimensional (1-D) conventional mechanically-transferable multifiber push-on (MPO) fiber connector and with a new two-dimensional (2-D) MPO-compatible fiber connector developed for this module. The VCSEL was mounted on the plastic-molded package using a highly precise completely alignment-free process using flip-chip solder bonding and ball-guide die bonding. These modules exhibit an optical coupling loss of 0.67plusmn0.23 dB (efficiency: 85.8plusmn2.93%) and a loss deviation of less than 0.26 dB for 100 matings with the fiber connector (MMF50). The modules were operated at a bit rate of 1 Gbps/ch without an isolator and showed floorless bit error rate (BER) performance at temperatures up to 70degC. At 1 Gbps/ch their optical sensitivity at a BER of 10 -11 was -26.0 dBmplusmn0.9 dB. These structures and techniques are applicable to high-density, high-throughput optical parallel interconnections and optical space-division switches
Kosaka, H.
Tomita, A.
Nambu, Y.
Kimura, T.
Nakamura, K.
The authors demonstrate single-photon interference over 100 km using a balanced gated-mode photon detector and a plug and play system for quantum key distribution. The visibility with 0.1 photon/pulse was more than 80% after 100 km transmission. This corresponds to the fidelity of a quantum cryptography system of more than 90% and a QBER of less than 10%, satisfying the security criteria.
The Mamut porphyry copper deposit of Paleocene to upper Miocene age is located on the northern end of the island of Borneo. The ore deposit is one of many mineralized centers which occur within and along a northwest-southeast-trending tectonic zone in the state of Sabah, Malaysia. Copper mineralization is associated with a potash-rich adamellite porphyry intrusion and is localized in the intrusion as well as in the wall rocks. The wall rocks consist of serpentinite and a sequence of clastic sedimentary rocks. Volcanic rocks are sparse and are represented only by very thin beds of tuff within the preore clastic rock sequence.Mamut is a copper-gold deposit with a total ore reserve of 179 million tons of 0.476 percent copper and about 0.5 grams per ton of gold. The ore mineral assemblage is dominantly chalcopyrite with minor molybdenite and sparse galena and sphalerite. Mamut is unusual because both pyrrhotite and pyrite occur as gangue sulfides. Ore-related alteration is characterized by strong silicification and the development of biotite, both of which occur within the ore shell. Quartz-sericite alteration with veins is commonly observed.