Frequency modulation (FM) noise spectroscopy with diode laser is applied to high-resolution Doppler-free spectroscopy of Cs atomic vapor near a dielectric surface with evanescent-wave pump-probe configuration. Both high resolution and high sensitivity are realized by using an extremely simple experimental setup, in which no sweep or precise tuning of laser frequency are required. Several experimental configurations of optical near-field spectroscopy are demonstrated, which is useful for an extensive study of resonant interactions of atoms and microscopic electronic systems in optical near-fields.

The prospects of electron spectroscopy of working organic electronic device structures are discussed. The experimental consideration and the result of actual measurement are presented.

The adsorption behavior of cytochrome c was investigated using slab optical waveguide (SOWG) absorption spectroscopy at the near ultraviolet region utilizing thin quartz plates as planar waveguides. SOWG absorption spectra of cytochrome c measured at constant time intervals showed significant influence of surface hydrophilicity and solution chemistry on the adsorption of this important heme protein in quartz surface. Being polar and typically amphoteric, the protein preferred adsorption on hydrophilic surface than on hydrophobic surface as implied by the lower absorbance data obtained in the latter than in the former. At lower ionic strength and in the absence of buffer, the protein molecules tend to adsorb on the quartz surface. Plots of near steady-state absorbance versus protein concentration follow hyperbolic pattern in the absence of buffer or at low ionic strength and become more linear as the buffer concentration is increased. The results presented here are explained in terms of the general qualitative understanding of protein adsorption at solid-aqueous interfaces and further aids in elucidating the properties of protein monolayers and films.

Human tissues conduct electricity about as well as semiconductors. However, there are large differences between tissues which have recently been shown to be determined mainly by the structure of the tissue. For example, the impedance spectrum of a layered tissue such as skin is very different to that of the underlying tissues. The way in which the cells are arranged and also the size of the nucleus are both important. Some of the recent developments in measurement and modelling techniques are described and the relationship between tissue structures and impedance spectra is outlined. The illustrations and examples look at the effect of premalignant changes on localised impedance spectra measured from cervical tissues. Electrical Impedance Tomographic measurements on lung tissue are used to show the maturational changes of lung structure in neonates. The conclusion contains some speculation as to what further research outcomes might occur over the next few years.

We have developed a 200-channel imaging system that enables measurement of changes in oxygenation and blood volume and that covers a wider area (45 cm 15 cm) than that covered by conventional systems. This system consisted of 40 probes of five channels, a light-emitting diode (LED) driver, multiplexers and a personal computer. Each probe was cross-shaped and consisted of an LED, five photo diodes, and a current-to-voltage (I-V) converter. Lighting of the LEDs and acquisition of 200-channel data were time-multiplexed. The minimum data acquisition time for 200 channels, including the time required for calculation of oxygenation and monitoring of a few traces of oxygenation on a computer display, was about 0.2 s. We carried out exercise tests and measured the changes in oxy- and deoxy-hemoglobin concentrations in the thigh. Working muscles in exercises could be clearly imaged, and spatio-temporal changes in muscle oxygenation during exercise and recovery were also shown. These results demonstrated that the 200-channel imaging system enables observation of the distribution of muscle metabolism and localization of muscle function.

This study is intended to realize an in-situ gas sensor based upon the principle of millimeter/submillimeter wave spectroscopy. In-situ gas sensor will be attractive because of gas selectivity, multiple parametric measurement such as gas temperature, pressure and density, and of the in-situ measurement capability. One of the major technical problem to be solved is to develop an instrument accurate enough to discern the spectrum change due to the variation of parameters such as temperature. In this paper a proposed gas absorption measurement system is investigated, which schematically consists of Fabry-Perot type gas cell for effective long path length, and vector signal processing to reject leak signal coupled between resonator input and output ports so as to achieve precise absorption measurement. Also included is an parametric study of oxygen absorption characteristics, which is served as the predicted value in the evaluation of the instrument. The experiment at 60 GHz and 120 GHz bands using oxygen demonstrates the effectiveness of the current system configuration.

In this paper, the distributions of two spectral intensities along the axis of an arc column of the breaking arc are measured by using a combination of a CCD color camera and an additional filter, and arc temperature and metal-vapor quantity are calculated, when copper electrodes interrupt circuits of dc 50 V/3.3 A and 5.0 A. As results; The spectral intensities of excited copper atoms are the strongest near the cathode and become weaker with distance from the cathode in the small number of breaking arcs. The spectral intensities become strong near the anode in the large number of breaking arcs. The average arc temperature in the cross-section of an arc column is high near both the cathode and the anode, and the temperature distribution in the cross-section of the arc column is high at the axis of the arc column, and the arc temperature along the axis of the arc column is high near both the cathode and the anode. The metal-vapor quantity is low near both the cathode and the anode, and it is much at the center of the arc column.

Photoacoustic spectroscopy (PAS) has recently received much attention especially for plant photosynthesis research, because this technique is capable of performing non-destructive measurement without any pre-treatment of specimens. So far we have developed a PAS system equipped with an open photoacoustic cell (OPC), which allows in situ and in vivo measurements of plant photosynthesis of intact undetached leaves. In this study, we have measured photosynthesis reaction using OPC and developed a Confocal Scanning Photoacoustic Microscopy (CSPAM) system, in which PAS is combined with confocal scanning laser microscopy. The system allows simultaneous measurement of acoustic signal and another signal such as fluorescence, and also gives two- and three- dimensional intensity distributions of these signals, thereby giving two- and three- dimensional information about photosynthetic activity of plants.

In a DC 50 V/3.3 A circuit, the spatial distributions of the spectral intensities of breaking arcs near the cathode for silver contacts were measured on the contact surfaces of three different shapes: flat and spherical (1 mm radius and 2 mm radius) and the arc temperature and the metal-vapor quantity were calculated from the spectral intensities. The influence of the contact shape on the arc temperature and the metal-vapor quantity were also examined, as well as the arc tracks on the contact surfaces and the gain and loss of the contacts. Findings show the distributions of spectral intensities are non-symmetrical from the beginning to the extinction of the breaking arc for the flat contact: However, they are symmetrical in the latter half of the breaking in spite of the number of breaking arcs and the shape of contact surface for the spherical contact. The relationship between the area of the arc tracks on the cathode and the shape of contact surface is the same as the relationship between the existent areas of measured spectra and the shape of the contact surface. For the spherical contacts, the arc temperature and the metal-vapor quantity are affected a little by the radius of the curved of contact surface and the number of breaking arcs. However, the longer the arc duration, the higher the metal-vapor quantity is in the latter period of the breaking arc. For the flat contacts, the metal-vapor quantity is lower than those for the spherical contacts. The gain and loss of the contacts are less and the arc duration is shorter for the flat contact than for the spherical contact.

Contact resistance of nickel hardened gold electroplate (NiHG) deposited on nickel-underplated phosphor bronze disk coupons (substrate) after thermal aging was measured with a hard gold-plated beryllium copper alloy pin probe by means of a four-point probe technique, compared to that of cobalt-hardened gold electroplate (CoHG). Surface of NiHG plated coupons after aging was analyzed by X-ray photoelectron spectroscopy (XPS) to investigate the influence of the oxide film formation during thermal aging on contact resistance of NiHG electroplate, compared to that of CoHG. Initial contact resistance of the NiHG coupons was less than 10 mΩ at a contact forces more than 0.05 N, increased to 10 mΩ at a contact force of 0.05 N after 100 hours aging at 200. In contrast, contact resistance of the CoHG coupons progressively increased with increase in aging time, reached 1000 mΩ even at a contact force of 0.05 N after 52 hours aging. XPS analysis for the NiHG coupons demonstrated that nickel oxide film was formed on the NiHG surface in conformity with parabolic growth kinetics, as cobalt oxide film formed on CoHG surface. However, a thickness of the latter film was approximately 4-fold larger than that of former after 100 hours aging at 200. The small increase in contact resistance of NiHG coupons after aging suggested to be due to inhibitory of nickel oxide film growth on the surface. The cause of relatively low and steady contact resistance of NiHG during thermal aging was discussed.

Recent technologies of organic film devices are reviewed. New technologies of fabrication and characterization of organic thin films, electro-mechanical conversion materials, and applications for electrical and optical devices are discussed. In this review paper, especially organic light emitting diodes, tunneling junctions using polyimide Langmuir-Blodgett films, tunneling spectroscopy and high-density recording, plastic actuators using conducting polymers, molecular self-assembly process for fabricating organic thin film devices are reviewed.

In this study the spectral intensities of a breaking arc were measured near the cathode and the anode between separating Pd contacts in a DC 50 V/5 A circuit, and arc temperature and metal-vapor quantity and density were calculated. Results show the radial distribution of temperature in the cross section of an arc column was constant both near the cathode and the anode from the beginning to the extinction of the breaking arc. Near the cathode the arc temperature in the position of the peak value of spectral intensity rose to about 6000 K at the beginning and remained constant, but near the anode it rose to about 6000 K at the beginning and then decreased towards the extinction of the arc. Both near the cathode and the anode metal-vapor quantity and density rose suddenly at the beginning. Afterwards, they fell near the cathode until extinction. But they became constant approaching extinction near the anode. And the metal-vapor quantity was greater and the density higher near the cathode than near the anode.

In a DC 50 V/5 A circuit, the relationship between the number of breaking arcs and the spatial distribution of the spectral intensity of breaking arcs of long duration near the cathode in palladium contact were examined through substitution of the contact surfaces of three different shapes: flat and spherical (1 mm radius and 2 mm radius). Findings show the distribution of spectral intensity in Pd arcs to be influenced remarkably by the shape of contact surface and the number of breaking arcs. However, the temperature of Pd arcs was affected neither by the shape of contact surface nor by the number of breaking arcs. The metal-vapor quantity present differed for flat and spherical surface contacts; however, it was not affected by the radius of the curved contact surfaces or by the number of breaking arcs. Additionally, the longer the duration of the breaking arc, the more metal-vapor was presented in the beginning of the arc. Furthermore, arc tracks on contact surfaces were observed with microscopes, clarifying that the relationship between the area of the clouded white metal on the cathode and the shape of contact surface is the same as the relationship between the existent area of measured spectra and the shape of the contact surface.

The development of a far-infrared imaging system based on ultrafast THz time-domain spectroscopy has opened a new field of applications of femtosecond technology. We describe the principle of this new imaging technique and report recent progress to augment the possibilities of "T-ray" imaging. These include sub-wavelength-resolution near-field imaging and three-dimensional tomographic reconstruction of a samples refractive index profile.

This paper describes a simple system of measuring the spatial distributions of spectral intensities with AgI-421 nm and AgI-546 nm among many optical spectrums emitted from an arc discharge between separating Ag contacts. In order to detect the intensities of two optical spectrums, the prototype equipment has two sets assembled with a CCD color linear image sensor, a lens and optical filters, which are arranged on rectangularity. The intensities of two spectrums can be recorded with 2 ms time-resolution within a long arc duration on a digital memory. The recorded digital signals are processed by using a personal computer in order to reconstruct two spatial distributions of spectral intensities in a cross section of arc column with the Algebraic Reconstruction Technique.

We compare interfaces of Nb/AlOx-Al/Nb and Nb/ZrOx-Zr/Nb junctions using secondary ion mass spectroscopy and cross-sectional transmission electron microscopy. We have clarified that an interface of the Nb/AlOx-Al/Nb junction is drastically different from that of the Nb/ZrOxZr/Nb junction. An adsorbed water vapor layer plays an important role in suppressing grain boundary diffusion between Nb and Al at the interface of the Nb/AlOxAl/Nb junction. In depositing Nb and Al at low power and cooling the substrate, it is important to control the formation of the adsorbed water vapor layer for fabricating Nb/AlOx-Al/Nb junctions exhibiting excellent current-voltage characteristics.

To investigate the effect of alkyl chain length and adsorption time on the charge-transfer complex formation, ultraviolet-visible absorption and inelastic electron tunneling (IET) spectroscopy measurements were carried out for the tetramethylphenylenediamine (TMPD; donor molecule) adsorbed dodecyl-, pentadecyl- and octadecyl-tetracyanoquinodimethane (TCNQ) Langmuir-Blodgett (LB) films. In the optical absorption spectra, the main peak of LB films shows a red-shift depending on alkyl chain length and adsorption time. Furthermore, the dependence on alkyl chain length and adsorption time are also shown in the IET spectra. These results demonstrate that adsorption LB methods enable to control the adsorption ratio of functional molecules and the CT complex formation.

A Ge/Si structure grown by chemical vapor deposition (CVD) is angle-lapped and characterized by the micro-Raman spectroscopy. Near the interface, the phonon mode due to the Si-Ge bond is clearly observed, which indicates that a SiGe alloy is formed by the solid-phase interdiffusion at the interface. The thickness of the interfacial alloy layer is about 0.2 µm. Amount of residual strain is estimated by comparing the measured phonon frequencies with those predicted from the composition profie, but the shift due to the residual strain is not appreciable. Both the interdiffusion at the interface and the nearly complete relaxation of the lattice mismatch are attributed to the high growth temperature of the CVD sample.

Thermal desorption spectroscopy (TDS) is applied to analyze the oxidation reactions of hydrogen-terminated Si(100) surfaces in both the heating and cooling processes after hydrogen desorption. The oxidation reaction of oxygen and water with a silicon surface after hydrogen desorption shows hysteresis in the heating and cooling processes. In the cooling process, oxidation finishes when the silicon surface is adequately oxidized to about a 10 thickness. Oxidation continues to occur at lower temperatures when the total volume of oxygen and water is too small to saturate the bare silicon surface. The reaction of water with silicon releases hydrogen at more than 500. Hydrogen does not adsorb on the silicon oxide surface. A trace amount of oxygen, less than 110-6 Torr, roughens the surface.