Casting technique for organic glass has been developed by means of radiation-induced polymerization of acrylic monomer in a supercooled state at low temperature. It was found that transparent polymer product without optical strain in static strain gauge could be prepared efficiently in a very short time by this method. The micro-strain was also examined by means of Twyman-Michelson type interferometer and the product at low temperature showed very small micro-strain. The reason for these facts can be attributed to the extremely high viscosity, the minimum temperature rising due to polymerization heat and the small volume contract during polymerization in this casting method. The practical monomeric systems consisting of mainly CR-39 and of mainly MMA were applied to this method and excellent materials were obtained as the result. Furthermore, the continuous production method for line focus Fresnel lenses has been developed by radiation polymerization using the soft gel sheet which dose not flow, but is soft and plastic.

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A simple machine for making hyperboloid lenses has been developed. This machine utilizes a simple geometry of hyperbola. A plastic rod can be easily cut into hyperboloid lens within 10 minutes and the obtained surface of hyperboloid lens is rather smooth. This simple machine is very useful for preparing experimental optical systems with very small aberration in laboratories.

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A possible method of making a large screen display is to apply a virtual image system with a large concave mirror. A large concave parabolic mirror of high quality to be used for this purpose, can be made inexpensively with rotation method.
In this case, plastic material, such as epoxy resin which hardens at room temperature, is formed into parabolic shape within a rotating dish. A mirror of 920 mm diameter and 1150 mm focal length, which has been fablicated by this method, shows sufficiently good characteristics for a virtual image display system.

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As the recent trend in plastic surface coating, methods of“dry processing”such as vacuum deposition, sputtering and ion plating are progressively used in place of“wet processing”. Especially, adhesiveness of coating to the plastic surface, has been much improved by the introduction of plasma ion processing. Among various methods of dry processing, the RF ion plating method seems to be most effective. In this method, the cold plasma produced by RF discharge, acts effectively to the plastic surface and the excellent adhesiveness od coating is obtained.

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A process to calculate the illumination (the flux density along a ray path) over an arbitrary surface in an optical system is described. If the process is applied with Skew Ray Trace Algorithm, various kinds of calculation of illumination can be performed quantitatively and economically. As an example of calculation, the illumination of ghost is shown.
Also, a caustic surface is obtained by the locations where flux density becomes infinity. Here, the caustic surfaces of two sample lenses are shown, and the relationship between the caustic surfaces and ray aberrations is discussed.

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It is well known that the decentering in the lens manufacturing process decreases the performances of lenses. A computer simulation method is developed to estimate loss of the yield in manufacturing process caused by decentering. The outline of this method is described, and the effect of sample number on the accuracy of this simulation is examined. The usefulness of this method is shown through an example to improve the yield and an experiment to compare the productivities of several lens types.

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A computer program for metal-dielectric multilayer film is described, which has capabilities of optimizing and evaluating optical characteristics. Damped least squares method is applied for the optimization process. Antireflection coatings are used as practical examples of the program.

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A special instrument was designed to measure quickly the spatial distribution of the resolving powers in a wide image formed by a telescope (including binocular telescopes except for the Galileian type). Details of the instrument and the distribution of the resolving power of a binocular telescope measured with the instrument are given.

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This paper describes a waveguide-type optical modulator developed for optical transmission systems. It covers crystal growth of a high quality LiNbO₃ single crystal used as a substrate, titanium diffusion technique to form a waveguide, as well as fabrication and fundamental properties of the waveguide-type optical modulator.

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The staining resistivity of the optical glass is not only related to the forming rate of the stained layer but also dependent on the visibility of the stained layer formed. Therefore. it should be determined by measuring the time needed to form the stained layer which gives a certain value of the visibility. We established the new measuring method based on such a consideration. In the previous measuring method for chemical durability, most of dense flint glasses were known to have relatively high staining resistivity. However, in spite of the relatively slow rate of formation of the stained layer, the visibility of the layer is considerably high due to the big difference in refractive indices between the formed layer and the bulk glass. Accordingly, it takes considerably short time to form the visible stained layer. In the new measuring method, most of dense flint glasses are considered to be the glass having poor staining resistivity. This corresponds well to the results obtained in manufacturing process.

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