Key Engineering Materials Vols. 364-366

Abstract: This study aimed to establish the coordinate transformation between the off-axis aspherics coordinate system σ and the axial symmetry aspherics coordinate system σ by transforming coordinates and present the computation models of asphericity in rectangular coordinate system and cylindrical coordinate system respectively. The asphericity expressions in both coordinate systems were applicable to the comparative sphere calculation of Off-axis aspherics with different figures. We selected an Initiation sphere in view of technology, along with equations in a right coordinate system for certain caliber and structure. Then, by numerical computation, we selected the best fitting sphere and simplifed the complex models by choosing a right coordinate system. At last, the solution for asphericity and the best fitting sphere curvature radius of off-axis aspherics were introduced by examples.

Abstract: This paper presents a high-precision, non-destructive measurement system for determining the thickness and refractive indices of birefringent optical wave plates. Significantly, the proposed method enables the two refractive indices of the optical sample to be measured simultaneously. The performance of the proposed system is verified using a commercial quartz optical wave plate with known refractive indices of 1.5518 e n = and 1.5427 o n = , respectively, and a thickness of 452.1428 μm. The experimentally determined values of the refractive indices are found to be 1.55190 e n = and 1.54281 o n = , respectively, while the thickness is found to be 452.189 μm, corresponding to an experimental error of approximately 0.046 μm. The measurement resolution of the proposed system exceeds that of the interferometer hardware itself and provides a simple yet highly accurate means of measuring the principal optical parameters of birefringent glass wave plates.

Abstract: With differential confocal pointing method, the ultra-precise machined surface can be measured with high resolution. In this technology, the differential confocal pointing signal, the zero point of the output diagram, may be affected by the different response of the two detectors, the different defocus of the two detectors, the accordance of the two pinholes in front of the detectors and so on. The paper aims at discussing the effect of these elements on the measuring signal. Through theoretical analysis of the output of the differential confocal microscopy (DCM), the conclusion that the pointing signal keeps fixed after the differential confocal system has been set up, does not change with the differences mentioned above, is presented. However, the resolution of the differential confocal system is concerned with the response performance and defocus of the two detectors. This is also confirmed by experiments.

Abstract: The scanning system which uses the non-linear focusing lens is usually accompanied by a major problem that is a non-constant scanning velocity of the spots in the projection plane. Moreover, the energy of the spots and the shape of the drilling holes would be affected. Hence, the focal lens of the scanning system usually uses the f-theta lens to solve this problem. This paper proposes a method utilizing the ZEMAX to analyze the commercial F-theta lens. The results indicate the F-theta lens can increase the quality of the drilling holes and amend the projection plane. In order to verify the analysis results, each diameter of an array holes drilled by the CO2 laser drilling machine would be measured. The experimental results can demonstrate that the percentage of the variation in the diameter of holes is close to the simulation results. Therefore, the method can effectively analyze the F-theta lens of the scanning systems.

Abstract: With an aim to achieve a breakthrough the choke point in research on system design, to achieve the transforming in multiple fields of view, the approaching to system efficacy limit in theory and improving smartness, pure diffractive optical system is chosen. The top idea and main strategy is developed. Some correlative model is established. In optimized design, global optimization algorithm is used to achieve wider spectrum range, multi field view, lower distortion and appropriate MTF. A kind of result works mainly in 3~5%m and 8~12%m with high ratio of more than 20:1 is evaluated. And this integrated multi-sensor electro-optical system satisfies the applied requirements o some criteria, such as Modulation Transfer Function (MTF), Spot Diagram (RMS) and Point Spread Function (PSF) etc., and achieves remarkable advantages in volume, weight, system efficiency and so on.

Abstract: For the 1:1 laser projection lithography system used to achieve large-area patterning with higher resolutions as well as higher throughput, the key parameters such as the laser beam geometry, the numerical aperture of projection lens, the laser source power and the pulse repetition rate are theoretically analyzed. It is expounded the process of uniform exposure in hexagonal beam shape, the advantages and limitations of 1:1 projection owing to numerical apertures deciding the resolution, as well as the cause of choosing larger laser power and pulse repetition rate. Meanwhile, the projection lens for a unit-magnification, refractive imaging system is tentatively simulationdesigned using ZEMAX optical design software. The optimized three-dimensional layout is plotted. For the designed results, the maximum optical path difference is smaller thanλ /4 within entire visual field. The resolution for feature sizes 10μm can be achieved within depth of focus 400μm by evaluating MTF. The maximum field curvature is within 10μm and the maximum distortion is small than 0.000007%. This fulfills the demands in technical specifications.

Abstract: Dynamic optical is a theory which we can deduce the object-image conjugated rations of optical system by researching motion group in optical system. It can unify various formula and methods of optical system which have motion group. Zoom system is a typical dynamic optical system. This paper will discuss how to apply the dynamic optical theory to zoom system design. With dynamic optical theory, we can derive the image motion compensating formula and the trace curve of the image motion compensating group. The cam can be fabricated according to compensating curve, which can ensure the stabilization of image plane and keep imaging quality. Moreover, a example of 30× zoom system is presented, which proves that the dynamic optical theory has some practicability for zoom system design.

Abstract: The formation of tool marks in single-point diamond turning is a fundamental study of the effect of materials swelling and recovery on surface roughness on a machined surface. A series of orthogonal face cutting tests has been conducted among plate aluminum alloy, oxygen-free high conductivity copper and electroless nickel phosphorus under the same cutting conditions by the use of facet tools with different front clearance angles. The results show that the regular width of the undulating pattern in tool marks could be explained by side swelling and the micro-waviness within a tool mark is caused by burnishing and recovery.

Abstract: In this paper, we are presenting a design method and its results for a space optical system with high resolution and wide field of view. This optical system can be used both in infrared and visible configurations. The designing of this system is based on an on-axis three-mirror anastigmatic (TMA) system. Here the on-axis concept allows wide field of view (FOV) enabling a diversity of designs available for the Multi-Object Spectrometer instruments optimized for low scattered and low emissive light. The available FOVs are upto 1º in both spectrum ranges, whereas the available aperture range is F/15 - F/10. The final optical system is a three-mirror telescope with two on-axis and one off-axis segment and its resolution is 0.3m or even lower. The distinguished feature of this design is that it maintains diffraction-limited image at wide wavelengths. The technological developments in the field of computer generated shaping of large-sized optical surface details with diffraction-limited imagery have opened new avenues towards the designing techniques. Such techniques permit us to expand these technological opportunities to fabricate the aspherical off-axis mirrors for a complex configuration.