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A hemi-paraboloidal solid immersion mirror (HP-SIM) was for the first time fabricated with the electrolytic in-process dressing (ELID) grinding technology. By improving the surface deviation and roughness of the HP-SIM to the order of ±0.3 µm and 4 nm, the spot size (FWHM) of 0.22×0.26 µm was obtained in the blue light concentration with the HP-SIM though fairly large side lobes were observed. A small-sized optical head was also designed with the HP-SIM, a pair of collimating lenses, and laser diode, which height can be reduced to 1 mm. Diffraction limited concentration is expected with the HP-SIM optical head, though the accuracy of less than ±1 µm is required for the alignment of the LD to the collimating lenses for both X and Y directions.

We have developed compound refractive lenses (CRLs) for cold neutrons, which are made of vitreous silica and have an effective potential of (90.1– 2.7×10 −4 i ) neV . In the case of compound refractive optics, neutron absorption by the material deteriorates lens performance. Thus, to prevent an increase in neutron absorption with increasing beam size, we have developed Fresnel lenses using the electrolytic in-process dressing grinding technique. The lens characteristics were carefully investigated with experimental and numerical simulation studies. The lenses functioned as a neutron focusing lens, and the focal length of 14 m was obtained with a 44-element series of the Fresnel lenses for 10 A neutrons. Moreover, good neutron transmission of 0.65 for 15 A neutrons was obtained due to the shape effect. According to comprehensive analysis of the obtained results, it is possible to realize a CRL for practical use by choosing a suitable lens shape and material.

ELID grinding is a method that realizes high quality mirror surface grinding in the nanometer order by use of electrolytically dressing metal-bonded wheels consisting of fine abrasives. Currently, ELID grinding is increasingly being applied as an ultra-precision grinding method to achieve desired surface roughness, high surface accuracy, high surface quality, and high grinding performance. This paper introduces the principle of ELID grinding and discusses some applications of ELID grinding to mirror surface grinding.

ELID-lap grinding is a method of constant pressure grinding which utilizes an electrically conductive wheel and the electrolytic in-process dressing (ELID) method. This method has the advantage of using micro grain-wheels above #10 000 and also, through simple modification, can be used on existing lap machines. To find the characteristics of metal-resin bonded wheels developed for ELID-lap grinding, experiments on the grinding of brittle materials were performed using wheels with a variety of grain diameters. The wheels used in the experiments were #8000, #120 000 and #3 000 000 metal-resin bonded diamond wheels (#8000 MRB-D, #120 000 MRB-D and #3 000 000 MRB-D wheels). The workpieces were silicon and glass. The results of the experiments showed that stable grinding can be achieved with the #8000 to #3 000 000 MRB-D wheels. With the #3 000 000 MRB-D wheel, very smooth surface finishes were obtained for both silicon (PV 2.8 nm) and glass (PV 2.5 nm). Atomic Force Microscope (AFM) and Scanning Electron Microscope (SEM) observations indicated these surfaces to be very smooth in the order of several nanometers, obtained by mechanical removal using an ultrafine wheel.

This chapter introduces a newly-developed profile measuring method with air-bearing cylinder slant probes to measure the profile in the wide range of angles with high accuracy. The air-bearing cylinder can be moved by electric-pneumatic regulator accurately with low friction. Since the measuring force can be controlled in a very low value, high measuring accuracy can be obtained. And the combination of multiple measurements by using slant probes enables to achieve high measuring accuracy in the points with steep angles. The airbearing cylinder slant probe can be also applied to general 3D-CMM to improve the measuring accuracy.

In this study, we attempted to develop a desk-top 4-axes machine “TRIDER-X” mounting a ELID system. This paper describes concepts and history of the machine, and detailed investigations on the performance of the machine. A concave mirror was ground using the desk-top 4-axes machine “TRIDER-X” mounting an ELID system. Good form accuracy was achieved.

In this research, a fused silica torus mirror with a surface roughness of 8.7 nm Ra were fabricated with highly efficient ELID) (electrolytic in-process dressing) grinding, and then polished with a φ 16mm polishing pad. The polishing was implemented in two processes: pre-polishing and final polishing. In the pre-polishing process, polyurethane foam type sheet was used. As a result, surface roughness of about 1.2 nmRa was obtained in the measurement of an area of 0.169×0.126 mm 2 using an interferometric microscope. In the final polishing process, the polyethyleneterephthalate fiber felt sheet used produced very good surface roughness. Through the analysis of the polished surface texture, the factors influencing surface finish were also investigated.

This paper introduces a new ultraprecision mirror surface machining system with ELID (Electrolytic In-Process Dressing). The machine has three linear axes, which can be controlled at a feeding resolution of 10nm under full closed feedback. 3-axes double hydrostatic guideway are used for sliding the machine, and hydrostatic bearing is used for the grinding wheel spindle. Ultraprecision mirror surface grinding, which achieved a surface roughness of 0.007 microns in Ra and surface straightness of 0.25 microns for a metal mold steel, was stably realized.

To achieve both high precision machining and high efficiency machining, the on-machine measurement system is inevitable. But conventionally there are no desirable sensors for on-machine profile measurement in the point of measurement accuracy and size. Authors have developed an ultraprecision profile measurement probe for on-machine measurement, which has three key technologies: laser interferometric displacement sensor and ultra-low pressure air-slide are inside and real-time measurement is possible by transmitting the current position data directly from the machine scales to the PC simultaneously together with the displacement data from the probe. The newly developed probe has high linearity, repeatability and traceability.

An on-machine measuring system based on the use of an LTP optical head was developed to accurately measure the slope error and profile error of long parts just after machining. Cylindrical surfaces can be measured completely by steering the beam up the sides of the cylinder with a rotatable mirror. To increase the reliability to measure the cylindrical surfaces, the optical system of the LTP head was improved. A personal computer collects all the data and controls the machine positioning and the beam steering mirror automatically.

We propose a method to make advanced thin-foil substrates for an X-ray telescope by press forming. Walter Type-I optics, which reflect X-rays twice with their confocal paraboloidal and hyperboloidal reflectors, have commonly been used in X-ray astronomy. However, it is difficult to make substrates for a large X-ray telescope with a high imaging quality. By forming two reflectors from one thin substrate, the accuracy of the angle between two reflectors is determined by the accuracy of a mandrel or a stamping die. We made a stamping die using a precision processing method at RIKEN. After several improvements of our pressing method, we have obtained the substrates with a figure error < 15 um, which corresponds to an angular resolution of about 2' at the focal plane, although a small waviness was found in the mirror surface. We also propose a new holding method of the foil to reduce a displacement of the foil positions. The foil is tightly held with three thin-supports with a thickness of 0.3 mm. We made the test model of a mirror housing, and found that the foil position was determined with σ~12μm.

In this study, we attempted to develop a cylindrical grinding machine applying the ELID technique, for use as a microtool. We also carried out a detailed investigation on the performance of the electrode turning method of the ELID system; a microcylindrical shaft and microangular shaft were ground using the cylindrical grinding machine applying ELID technique. Good dimensional accuracy was achieved.

For the purpose of realizing the flat surfaces of composite parts made of components with different properties, the finishing of such parts by a lapping method based on the ELID technique (ELID-lap grinding) was investigated. The composite parts used in this experiment were fabricated from copper and resin by the film lamination method. After 15 minutes of grinding, surface bumps could be smoothly ground from 15 μ m to 0.4 μ m The results confirmed that the method proposed is effective for smoothly grinding composite parts.

A hemi-paraboloidal solid immersion mirror is successfully fabricated with the ELID (electrolytic in-process dressing) grinding technology and the spot size obtained was 150% of that for diffraction limited processes. Small sized optical head would be possible with the HP-SIM, which size is comparable to that of a magnetic head for HDDs.

We have developed compound refractive prism for cold neutrons. To prevent an increase in neutron absorption, we have developed prism array like a Fresnel lens. The prism characteristics were investigated with experimental and numerical simulation studies. We achieved transmission of 0.75 and refractive angle of 7.5 mrad for 15 neutrons with 49 layered prism array.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

X-ray optics is advancing rapidly and being applied to numerous fields. X-ray mirrors may serve as one of the most important devices giving tremendous influence on the performance of a whole system.

Recent techniques for the fabrication of fine optical components have rapidly been developed as the expansion and development of information networks around the world.

X-ray optics is advancing rapidly and being applied to numerous fields. X-ray mirrors may serve as one of the most important devices giving tremendous influence on the performance of a whole system. X-ray mirrors require for higher precision than any other parts. But the technique which produces such mirrors has yet to be established. In this paper the applications of the ELID grinding technique1),2), which is known widely as a method for producing high precision ground surfaces in a short period of time, are described for X-ray mirrors.

The development of the micro-fabrication of structural components such as ceramics, optical glass, alloy steels etc., is increasingly required with the rapid growth of production in the recent years. The ELID (Electrolytic In-Process Dressing) grinding technique is a new grinding process using rigid metallic bond diamond wheels with the assistance of a special pulse electrolytic in-process dressing method.

Recent techniques for the fabrication of fine optical components have rapidly been developed as the expansion and development of information networks around the world. Generally optical components require higher accuracies than any other parts, and the fabrication of fine optical components require special techniques additionally. So it has been very difficult to fabricate them with high efficiency and high accuracies by conventional methods.

Nowadays many plastic lens are used in various optical systems, because the plastic lens can be mass-produced cheaply by the injection molding. But it is very difficult to produce a few plastic lens cheaply, because it requires much time and cost to make an injection mold. Turning is a way to make a few plastic lens directly and cheaply, but the plastic lens made by turning is not so good for optical lens, because the cutting marks give bad influence on optical characteristics of the plastic lens.

Recent demands for ultraprecision machining has been for higher precision. The ELID grinding technique is widely known as a method which produces high precision ground surfaces in a short period of time.1) Aspherical optics, one typical example of super precision parts, require not only good mirror surface finish but also high form accuracy.2) But it involves considerable difficulty to achieve both good mirror surface finish and high form accuracy. The authors have proposed a new form control system for achieving high form accuracy regularly and efficiently in aspherical ELID grinding, and successful results could be obtained through some experiments3),4). But there had been some conditions, under which the profile errors could not converge because the radius of the grinding wheel decreased by the wear. This paper proposes a new form compensation method which can be applied to the condition under which the grinding wheel is much worn.

Recently with a rapid advance of new material industry, the new materials such as ceramics and glass are increasingly applied to precision machine parts and optical parts etc.. Therefore, requirements of advanced slicing technique for precision slicing of these materials having the features of hardness and brittleness is gradually increasing. Generally, the slicing method using metallic bond diamond blades is using for the slicing of the hard and brittle materials. However, since the diamond blades of upper grits size #200 cannot be used due to the loading of blades etc., it is difficult to achieve the good slicing surface with high quality. In order to achieve the good slicing surface with high quality, post processing operations such as polishing and lapping must be carried out after slicing operation. Therefore, to obtain simultaneously excellent slicing surface such as mirror surface without the post processing operation, development of advanced slicing technique using a metallic bond diamond blade with fine grain size is essential. ELID (Electrolytic In-Process Dressing) is a new grinding technique which the protrudent gains of wheel is controlled and maintained by assistance of the electrolytic in-process dressing(ELID) and especially possesses the excellent capabilities for the fine or mirror surface grinding of hard and brittle materials1). Many studies on various grinding techniques applying ELID grinding have been reported until now2),3). In this study, ELID-grinding slicing technique to realize fine and mirror surface slicing of hard and brittle materials is proposed. A mirror surface slicing machine installed with the proposed ELID-grinding slicing system is developed and its performance is evaluated.

Due to the progress in fiber optics, optical storage systems and portable information devices, fabrication technologies for micro optical components becomes more and more important. The fabrication process of micro optical componets especially deep concave glass micro lens is facing a number of diffculties: (1)Since the diameter of the micro optical component is very small and the depth of the surface is large, the grinding wheel must have even samller diameter. (2)In order to obtain optimum cicumference speed, the rotation speed of the grinding wheel becomes extremely high. In order to overcome those problems, inclined grinding wheel can be used to cut the deep concave surface. This method solves the first problem but still extremely high rotation speed is necessary. The authors present a new resolution to those problems using ELID (ElectroLytic In-process Drssing) grinding method. Using ELID grinding, the grinding wheel is continuously dressed during the machininig process and always kept sharpened. This results in a very high quality surface finish even under low circumference speed. Fabrication example of glass micro concave lens (radius:4.6mm) is carried out with small grinding wheel (diameter 5mm) at relatively low rotation speed of 20,000 rpm, which is equivalent to 300m/min circumference speed. Surface roughness of 40nmp-ν and profile accuracy of approximately 1μm was obtained.