A review of the history, the excitation and oscillating mechanisms, and the technical pr-oblems in various ultraviolet lasers are given, including: (1) Gaseous discharge; ionized gas laser, metal vapor ion laser, molecular nitrogen laser and molecular hydrogen vacuum ultraviolet laser. (2) Harmonic oscillation ; 5th harmonics of the radiation of a Nd3+ glass (1.06μm) laser and continuous harmonic oscillations of Ar II lasers. 3) Dye laser; laser and flashlamp pumpings.
Development of laser techniques enables us to obtain one of the most powerful diagnostics of high temperature and density plasmas as an activespectroscopy. The theory of light scattering from electrons in the plasma is reviewed, and recent developments in the research on diagnostics of plasma by using laser light scattering and correlation are summerized.
A slotted disk type velocity selector for molecular beams has been constructed with thin disks made from stainless steel plates by chemical etching. The principle relating to the arran-gement of the disks is described and an example of such an arrangement used in the present work is also shown.
Various photographic images, in which the MTF have peaks at several special spatial frequencies; 0.5, 1.0, 2.0, 3.0, ……lines/mm and the over-all gradients of the objective tone reproduction characteristics are varied, are made by the masking technique. In this paper, it is shown that the subjective impressions of these photographic images, such as image quality, tone, contrast, and sharpness can be well correlated with the psychophys-ical evaluation function expressed by Eq. (8), which is not only a function of the MTF and the gradient of the tone reproduction characteristics of the image transfer systems, but also of the MTF of the visual system. Especially, if a weighting function such as the equivalent eye bandpass in the visual system is defined, subjective evaluations of sharpness can be successfully related to the psychophysical evaluation function expressed by Eq. (9).