Development in the fabrication techniques of aspheric surface is reviewed. While there is almost no problem in the fabrication of low-accuracy aspheric surface such as condensers and ophthalmic lenses, mass production of high-accuracy aspheric surface is still very difficult. The production of aspheric surface has to be studied as a synthesized technique of optical design, fabrication and test. Here is mainly described the fabrication process. A number of fabrication methods have been proposed. According to their working principles, these are classified into 13 groups; drum method, cam following method, link method, numerical control nethod, thermal sagging method, vacuum sagging method, vacuum evaporating method and others. For a given aspheric surface a method should be emploied in view of its accuracy, cost, capacity, etc. A process to mass-produce high-accuracy aspheric surface is discussed.
Several features of natural cleavage of KCI crystal obtained from the rapid cooling of the melt are discussed by using the method of computer simulation as follows: (1) Simulation is carried out on the assumption that certain imperfections are distributed at random in a one dimensional crystal and certain pairs lead to the cleavage. The simulation gives several characteristic features of the cleavage including the distribution of edge lengths of crystal fragments which resembles that from the experiments. (2) When the above type of distribution is extended to that of the imperfections, the relation between the distribution of the cleavage and the imperfections can be calculated and the result is in good agreement with the simulation.
When melted KCI is cooled somewhat rapidly in a crucible, crystal fragments of various sizes are obtained. Writers observed these fragments by means of monochromatic photography at 465, 353, 280 and 270 mg, and the following results are observed. (i) Giant clusters of optical defects are of microscopic scale in various shapes: stripe, point and lumps. (ii) Some of the defect clusters are closely related with the defect structures (step line, lumps, etc.) observable with the usual microscope, but others are not. (iii) Some stripe pattern of defect cluster may appear on the growing surfaces during the process of crystal growth. (iv) Optical characteristics of these defect clusters can be schematically classified into five kinds.
As the first step in constructing a multi-purpose analog-digital hybrid processing system, which allows several kinds of waveform preprocessing of the raw data from scientific instruments, one of the functional units for the smoothing operation is introduced. The whole system of the processor consists of a magnetic drum memory and analog hybrid operational circuits. The principle of the smoothing operation is based on the numerical filtering using the weighted moving average procedure. Time delay of the data in operation are executed with the magnetic drum memory, of which peripheral circuits are extremely simplified. The succeeding hybrid operational circuits calculate the weighted moving averages in real time. The overall accuracy of the system is better than±0.1% which is sufficient for the processing of data from scientific instruments. It is possible to use this system for a wide variety of waveform processing besides the smoothing. The effect of processing is demonstrated by smoothing a noisy infrared absorption spectrum.
The scanning electron micro probe method is a useful method in performing electron probe microanalysis of materials. In taking the electron beam scanning pattern, however, it is necessary to set up a suitable photographing condition, which is governed by the following factors: the operative voltage, specimen current, scanning speed of electron beam, brightness of oscilloscope used etc. This paper presents an apparatus for the determination of the best condition for photographing an X-ray or electron image of the surface of specimen under a given state. It is shown from some experiments that a very clear X-ray image can be taken by using the present apparatus.
An ultra-high-speed stroboscopic spectrometer utilizing an image converter camera as a signal sampling system is described. Plural sensing heads, each of which is composed of a photomultiplier tube and a horizontal slit, are aligned in a vertical direction on the fluorescent screen of the camera so as subsequently to sample small portions of the streaked image in every vertical sweep. Another feature is the stable processing electronics which contains specially constructed boxcar integrators for averaging the sampled signals from the sensing heads, under compensation of the dark current fluctuation. These arrangements make it possible to display time-resolved spectra at different instances on a multi-pen recorder, simultaneously. The attainable resolution time of this prototype instrument is as short as 0.3 nanosecond. To demonstrate the performance, the results of transient spectroscopic measurements for radiations from nanosecond light pulsers are presented.
Channel multiplier plates using a lead silicate glass were developed and the gain characteristics were examined, This paper deals with the method of their production in detail ; for example, tubing of micro-capillary, assembling of many channels and hydrogen treatment. The plates are composed of 100μm diameter channels and on the surface of the channels a conducting layer is developed by hydrogen reduction of PbO contained in glass. The total resistance is adjusted to 250MΩ allowing for temperature rise by Joule's heat. The electron gain reaches up to 108 at 3 kV dynode voltage and the background count rate is very low. Pulse height distribution measured at this voltage shows like a gaussian curve, but the distribution is an exponential type at a lower voltage.
This paper presents some experimental results concerned with the competition effect between 5682 Å and 6471 Å CW lines in the KrII ion laser by D. C. excitation. If each line is interrupted alternately for 60 seconds, and intensity changes of both lines are measured, two changes of long response time are found in the intensity of one oscillation line caused by the interruption of the other. One is about 5 seconds and the other is about 40 seconds. When a Fresnel Reflection Attenuator, which causes the same loss for both lines, is inserted in a common cavity, it is found that the 5682 A line has its maximum power not at the point of minimum cavity loss, but at the point when the 6471A stops oscillating.