This report reviews recent developments in the investigation of photo-induced optical and structural changes observed in various amorphous chalcogenides. The main subject is the reversible photostructural change in amorphous As2S3, and it is shown that the phenomenon is unique to the amorphous state. First, the chemical bonds and electronic structure of the As-S system are determined by the XPS technique. Second, the irreversible photobleaching observed in flash-evaporated As2+xS3 is described, and its kinetics are clarified by the detailed structural analyses. Finally, the reversible photostructural change accompanying photodarkening is discussed on the basis of detailed optical and structural studies, leading us towards a more complete understanding of the phenomenon.
Transparent conducting films of tin oxide and Sb-doped tin oxide with high conductivity, transparency, and hardness, were deposited on glass plates by the vapour blowing method using a tin salt of an organic acid. The characteristics, stability and structures of the films depend mainly on the substrate temperature and the impurity concentration during deposition. The films in routine process have a resistivity of about 6×10-3 Ω•cm, and a transmittance of above 80% at 600 nm. The Sb-doped tin oxide films are very stable and no aging effect was observed.
In an ordinary low pressure discharge tube, the axial electric field in a positive column has usually been evaluated without the diffusion loss of electron energy to the wall. In a discharge tube with small radius such as laser tubes, however, we must consider this diffusion loss, since in such a case the ratio of the diffusion loss to the collision loss is not negligibly small. In this paper, we theoretically analyze the axial electric field in a positive column including this diffusion loss, together with numerical values for He and Ne. From the results, it is shown that the effect of diffusion loss becomes more pronounced if the mean free path of electron is larger than the tube radius. Furthermore, the calculated results are compared with the experimental results, and, although a satisfactory agreement can not be obtained, some qualitative characteristics show that the above statement is valid.
A method of remote measurement of the particle size and density distribution of water droplets has been developed. In this method, the size of droplets is measured from the Mie scattering parameter which is defined as the total-to-backscattering ratio of the laser beam. The water density distribution is obtained by a combination of the Mie scattering parameter and the extinction coefficient of the laser beam. This method was examined experimentally for the mist generated by an ultrasonic mist generator and applied to clouds containing rain and snow. Compared with the conventional sampling method, the present method has advantages of remote measurement capability and improvement in accuracy.
A thermoelectric transistor thermometer is a grafted thermometer composed of a thermocouple, a transistor thermometer and a suitable operational amplifier which needs no reference temperature. The proportional constant γ of the transistor thermometer is adjusted to be equal to the temperature coefficient β of the thermocouple by means of an operational amplifier, and the sum of the e. m. f. and the voltage of the transistor thermometer is measured. It is proved theoretically that the temperature to be determined is known from the measurement of the voltage. Experiments are carried out with two typical circuits, one which enables us to measure the sum of e. m. f. of the thermocouple and the voltage of the transistor thermometer, and the other to measure the sum of the voltages multiplied by n. Results of experiments show that the outputs of the trial thermoelectric transistor thermometer agree fairly well with the e. m. f. of a thermoelectric thermometer of the same kind with the reference temperature of 0°C.
This paper deals with two topics. The first is the construction of a polarization analyzer which enables us to determine the four Stokes' parameters of light changing its state of polarization with time. Using the polarization analyzer, the technique for stabilizing an internal mirror laser by monitoring the intensity ratio of the two orthogonal linearly polarized components, was found on an experimental basis. The second topic is the construction of a simple stabilized laser based on the above technique. The single mode output of the stabilized laser was 0.47 mW, and the frequency stability was 1.02×10-7.
A plasma flame, whose cross-section is rectangular, can be produced by a particular type of a nozzle. It is composed of a two-stage entrance constrictor of circular cross-section and an exit constrictor of rectangular cross-section. The arc voltage of the newly developed nozzle is less than that of the ordinary cylindrical one, and thus the effluent volume of a plasma is decreased. However, the stability can be improved conspicuously, because the magnitudes of axial and radial fluctuations of a plasma flame by the system is reduced to half that of the conventional one.