After brief introduction of our new microscope unit with an immersion objective and ionic liquid used as a refractive index matching medium, in this paper, we describe the studies on dipole orientation imaging of single molecules under high vacuum conditions as one of the important applications of our microscope.

In situ UV-vis. absorption spectra of cytochrome c adsorbed on ITO electrode was observed with slab optical waveguide spectroscopy combining pulse potential step (PPS) between 0.3 and -0.45 V vs. Ag/AgCl. The amount of cytochrome c adsorbed on ITO electrode was estimated from the amount of coulomb of the peaks in cyclic voltammogram to be about a monolayer coverage in this experimental condition. Spectral change between oxidized and reduced cytochrome c by PPS was finished in about 20 msec with phosphate buffer solution. The results strongly proved that SOWG spectroscopy should be effective for in situ observation of ET reaction kinetics of surface adsorbed molecules.

We have developed a portable NIRS-based optical BCI system that features a non-invasive, facile probe attachment and does not require muscle movement to control the target devices. The system consists of a 2-channel probe, a signal-processing unit, and an infrared-emission device, which measures the blood volume change in the participant's prefrontal cortex in a real time. We use the threshold logic as a switching technology, which transmits a control signal to a target device when the electrical waveforms exceed the pre-defined threshold. Eight healthy volunteers participated in the experiments and they could change the television channel or control the movement of a toy robot with average switching times of 11.5 ± 5.3 s and the hit rate was 83.3%. These trials suggest that this system provides a novel communication aid for people with motor disabilities.

Ridge optical waveguides (OWGs) of fluorinated polyimides were deposited on a quartz crystal microbalance (QCM), and a hybrid sensor employing the OWG spectroscopy and the QCM technique was prepared. A polyvinyl alcohol (PVA) film with CoCl2 was deposited on the OWG, and humidity sensing characteristics were investigated. White light was entered into the waveguide and the output light spectra was observed. The output light intensity markedly changed because of the chromism of CoCl2 by humidity sorption. During the output light measurement, the QCM frequency was monitored simultaneously. The humidity dependences of the QCM frequency and output light were also investigated in a range from 10% to 70%. Furthermore, the response to hydrofluoroether (HFE) was observed, and the change in the output light was hardly observed because CoCl2 does not exhibit chromism in HFE sorption.

Solution-based organic field-effect transistors (OFETs) with low parasitic capacitance have been fabricated using a self-aligned method. The self-aligned processes using a cross-linking polymer gate insulator allow fabricating electrically stable polymer OFETs with small overlap area between the source-drain electrodes and the gate electrode, whose frequency characteristics have been investigated by impedance spectroscopy (IS). The IS of polymer OFETs with self-aligned electrodes reveals frequency-dependent channel formation process and the frequency response in FET structure.

In situ observation of the adsorption process and the states of cytochrome c on glass/solution interfaces, and the functionality of the reduction reaction of adsorbed cytochorome c were performed by using slab optical waveguide (SOWG) spectroscopy. The peak position of the absorption band of cytochorome c adsorbed on a bare glass surface was almost the same as that of that in solution. The cytochorome c adsorbed on glass/solution interface was reduced by sodium dithionite solution. The adsorbed cytochorome c was still maintained its functionality after immobilization.

The synthesis of single- and double-wall carbon nanotubes by gas flow-modified, catalyst-supported chemical vapor deposition (CCVD) is reported. We have investigated the gas flow condition dependence on the synthesis of carbon nanotubes (CNTs) by placing blocks in the CCVD reactor. Carbon nanotubes having large diameters are preferentially grown under turbulent flow conditions. This indicates that the diameter distribution of CNTs can be controlled by modification of the gas flow condition in the CCVD.

We carried out degradation analysis of a blue phosphorescent organic light emitting diode by both impedance spectroscopy and transient electroluminescence (EL) spectroscopy. The number of semicircles observed in the Cole-Cole plot of the modulus became three to two after the device was operated for 567 hours. Considering the effective layer thickness of the initial and degraded devices did not change by degradation and combining the analysis of the Bode-plot of the imaginary part of the modulus, the relaxation times of emission layer and hole-blocking with electron transport layers changed to nearly the same value by the increase of the resistance of emission layer. Decay time of transient EL of the initial device was coincident with that of the degraded one. These phenomena suggest that no phosphorescence quenching sites are generated in the degraded device, but the number of the emission sites decrease by degradation.

In situ observation of electrochemical activity and time dependent characteristics of cytochrome c (cyt c) was carried out in 0.01 M phosphate buffered saline (PBS, pH 7.4) containing 20 µM cyt c solutions at bare indium-tin-oxide (ITO) electrodes by using a cyclic voltammetry (CV) and a slab optical waveguide (SOWG) spectroscopy. The bare ITO electrodes could retain the electrochemical activity of cyt c in the PBS solutions, indicating the great advantage of using ITO electrodes against other electrode materials, such as gold (Au). The CV curves and simultaneously observed the time-resolved SOWG absorption spectra in the consecutive cycles implied that the cyt c molecules could retain its own electrochemical function for a long time.

In-situ measurement of photoelectron spectra of polypyrrole during electrochemical undoping/doping cycles has been carried out by using an open-type electrochemical cell. It has been observed that the ionization potential decreases with decreased electrochemical potential. This result seems to be reasonable because the decreased electrochemical potential corresponds to the undoping or recovery of electrons into vacant state of valence band.

The surface amino groups of plasma-polymerized films prepared from various nitrogen-containing monomers were quantitatively characterized for bioelectronic and biomedical applications. X-ray photoelectron spectroscopy (XPS) measurements were conducted on two kinds of surfaces: pristine surfaces of plasma-polymerized film prepared using various nitrogen-containing monomers, and theirs surfaces whose amino groups had been derivatized by a primary-amine-selective reagent carrying an XPS label. The XPS data showed that the maximum surface density of amino groups for this film was 8.41013 cm-2. Amino groups constituted 14-64% of all surface nitrogen atoms (NH/N), depending on the monomer used.

Time-of-Flight Mass Spectroscopy (TOF-MS) with superconducting detectors has two advantages over MS with conventional ion detectors. First, it is coverage for a very wide range of molecule weight over 1,000,000. Secondly, kinetic energies of accelerated molecules can be measured at impact events one by one. These unique features enable an ultimate detection efficiency of 100% for intact ions and a fragmentation analysis that is critical for top-down proteomics. Superconducting MS is expected to play a role in, for example, the detection of antigen-antibody complexes, which are important for medical diagnosis. In this paper, how superconductivity contributes to MS is described.

We demonstrate single electron counting on an alkanethiol-protected Au nanodot in a double-barrier tunneling structure by noncontact atomic-force spectroscopy (nc-AFS). The Coulomb step width dependence on the Au nanodot diameter is observed. Evaluation of fractional charge Q0 and contact potential difference by nc-AFS reveals a Vd-independent voltage shift due to Q0.

In situ observation of the adsorption process and reduction behavior of hemoglobin adsorbed on a bare glass surface was studied using slab optical waveguide (SOWG) spectroscopy. The peak position of the absorption band of hemoglobin adsorbed on the glass surface was almost the same as that of hemoglobin in solution. This result agrees with results previously reported by our group. The adsorbed hemoglobin molecules were also reduced by sodium dithionite solution. The adsorbed hemoglobin molecules still maintained their function in this experimental condition.

In situ observations were mainly performed by using slab optical waveguide (SOWG) spectroscopy synchronized with potential step measurements to investigate the time dependent spectral change of the adsorbed heptyl viologen cation radicals (HV+) in thin deposition layer on indium-tin-oxide (ITO) electrodes. Several absorption bands, which indicated a monomer and dimer of HV+ were co-adsorbed on ITO electrode surface with a monolayer or a few layers deposition, were observed in UV-visible region. The time dependent spectra yielded some important molecular information for the adsorption phenomena of HV+ on the electrode surface. All observed absorption bands disappeared completely when the electrode potential of -200 mV vs. Ag/AgCl was applied, which indicated the adsorbed HV+ species were electrochemically reoxidized on the ITO electrode.

In frequency-domain multiplexing (FDM) for TES signals, a magnetic field summation method utilizing a multi-input SQUID has the fundamental merit of small degradation of the signal-to-noise ratio. We formulated shifts of the operation point due to a common impedance and cross talk currents. These effects are evaluated for several FDM methods, and the requirements for the bandwidth and filters are summarized. The design parameters of multi-input SQUIDs and a flux locked loop driving circuits are also presented.

We observed the optically forbidden energy transfer between cubic CuCl quantum dots coupled via an optical near-field interaction using time-resolved near-field photoluminescence (PL) spectroscopy. The energy transfer time and exciton lifetime were estimated from the rise and decay times of the PL pump-probe signal, respectively. We found that the exciton lifetime increased as the energy transfer time fell. This result strongly supports the notion that near-field interaction between QD makes the anti-parallel dipole coupling. Namely, a quantum-dots pair coupled by an optical near field has a long exciton lifetime which indicates the anti-parallel coupling of QDs forming a weakly radiative quadrupole state.

Recently, DOAS (differential optical absorption spectroscopy) has been used for nondestructive air monitoring, in which the LS (least squares) method is used to calculate trace gas concentrations due to its computational simplicity. This paper applies the ICA (independent component analysis) method to the DOAS system of air monitoring, since the LS method is insufficient to recover the desired spectra perfectly due to sparsity characteristic. If the sparsity of reference spectra in the DOAS system imposes the assumption of independence, the ICA algorithm can be used. The proposed method is used to regress the observed spectrum on the estimates of the reference spectra. The ICA algorithm can be seen as a preprocessing method where the ICs of the references are used as the input in the regression. The performance of the proposed method is evaluated in simulation studies using synthetic data.

We have developed a novel basic technology for terahertz (THz) imaging, which allows detection and identification of chemicals by introducing the component spatial pattern analysis. The spatial distributions of the chemicals were obtained from terahertz multispectral transillumination images, using absorption spectra previously measured with a widely tunable THz-wave parametric oscillator. We have also separated the component spatial patterns of frequency-dependent absorptions in chemicals and frequency-independent components such as plastic, paper and measurement noise in THz spectroscopic images. Further we have applied this technique to the detection and identification of illicit drugs concealed in envelopes.

The DC resistivities of silicon germanium thin films on Si substrates by a non-contact and non-destructive technique using terahertz time domain spectroscopy (THz-TDS) agree with the values obtained by the four-point probe measurement. In the present experiment, the mobility has not been precisely determined owing to the limitation of the frequency range in our equipment (from 0.1 to 1.5 THz). However, when the mobility becomes large enough, this method will be highly useful in evaluating semiconductor thin films, since the method gives the same data as those from Hall measurement without sample processing or electrode contact to sample.