Precision glass molding (PGM) technology provides a possibility of rapidly manufacturing optical lenses with large volume, high precision, and complex shapes. It is difficult to fabricate micrometer-level structures in common PGM mold materials like tungsten carbide (WC) using a grinding/polishing approach. But no literature has pointed out how to design the dimensional tolerance of molds to ensure the molding accuracy in the case of the molds working in a temperature range of several hundreds of degrees Celsius. In this paper, a theoretical model is established based on the general molds designed sizes. The finite element method (FEM) and the PGM experiments were carried out. The measuring results of the decenter and tilt of the molded lens indicated that the optimization was effective and could be applied to other PGM experiments.
The fabrication of high-precision mold core can make the optical elements of freeform surface be mass-produced by plastic injection or glass mold pressing. However, diamond tools cannot directly cut ferrous materials due to rapid wear of tool. Therefore, the technology of ultrasonic assisted diamond turning is proposed to process the freeform surface on the die steel in this paper. The characteristics of vibration servo machining are analyzed and discussed by theoretical modeling and digital simulating. After fabricating freeform surface on die steel by this technology, the value Ra of surface roughness can be achieve to 5.905nm.
An optimal method was presented to prevent the decrease of diffraction efficiency when the infrared diffractive optical elements working in a wide temperature range. The method can lower the cost of thermal infrared diffractive lenses by decreasing the microstructure height and volume of multilayer diffractive optical elements (MLDOEs). The diffraction efficiency of the results was compared to the previous methods with wavelengths between long wave infrared and middle wave infrared. Those comparisons show the better temperature stability of MLDOEs when the elements working in a wide temperature range.
Single diamond turning is usually used to fabricate multilayer diffractive optical elements (MLDOEs). The choice of diamond tools directly influences the profile error and surface roughness error of MLDOEs. Those two errors will cause the shadowing effect and scattering effect, which decrease the diffraction efficiency of MLDOEs. The relationship among diffraction efficiency, cutting tool radius, feed rate, and microstructure periods was presented. A model to find the optimal cutting tool radius and feed rate before the fabrication was put forward to balance the influence of shadowing effect and scattering effect, which can maximize the polychromatic integral diffraction efficiency. The effect of diamond cutting tool radius and feed rate in the manufacturing process of MLDOEs is discussed and analyzed numerically, and the results will be intended as guidelines for manufacture of MLDOEs to achieve diffractive surface-relief profile with high quality.
The signal-to-noise ratio (SNR) and noise equivalent radiance (NER) are important characteristics of an electro-optical systems sensor. A new method to improve the system’s SNR and reduce the NER was studied by analyzing the radiometric calibration data of the system. An image was obtained, when the system was illuminated by the uniform light source outputting from integrating sphere. The adjourn pixels were binned by n×n pixels (n=2, 3, 4, 5) in this image. And the digital numbers of binning pixels were added together. The new images were achieved. With 5×5 pixels binned, the SNR increased from 165.7 up to 842.3, which is improved almost 5 times. At the same time, the NER decreased from 0.077(W/m2/sr) to 0.015(W/m2/sr), which is declined by nearly 5 times. With the binning pixels up to n×n, the SNR and NER were enhanced and decreased almost by n times, respectively.
According to the expression of the phase delay and diffraction efficiency of the diffractive optical elements(DOEs), the expression of diffraction efficiency of multilayer diffractive optical element(MLDOEs) with the height error in fabrication process was described in this paper. We selected the PC and PMMA used usually at optics as substrate material of MLDOEs, and analyze the height error range of multilayer diffractive optical element with consideration of polychromatic integral diffraction efficiency basing on the mathematical analysis model of the relationship between height error and diffraction efficiency for MLDOEs. The range of height error the diffraction efficiency of MLDOEs was given. This model can be used to guide the design and fabrication process of hybrid diffraction refractive optical system for optical engineer.
According to the expression of the phase delay and diffraction efficiency of the diffractive optical elements(DOEs), the expression of diffraction efficiency of refraction and diffractive optical element with the tilt and decenter error in fabrication process was presented in this paper. Analysis results show, in the wavelength band of 501nm-554nm, the cycle of 500μm, the center wavelength of 521nm, when the tilt angleα increases form 0° to9.8° , the diffraction efficiency is above 99%; when the tilt angleα increases form 9.8° to 29.7° , diffraction efficiency is above 92.5%; when the tilt angleα is above 29.7° , the diffraction efficiency declines rapidly, diffraction efficiency is 0 when the tilt angleα is above 58° . When the decenter Δ increases form 0nm to 21.6μm,the diffraction efficiency is above 98%; when the decenter Δ increases form 21.6nm to 63.3μm, the diffraction efficiency is above 90%; when the decenter Δ is above 63.3μm, the diffraction efficiency declines rapidly, diffraction efficiency is 0 when the he decenter Δ is above 241.7μm. To sum up the results of analysis,mathematical analysis model of the relationship between the decenter and tilt error of diffractive optical element in processing and the diffraction efficiency can be used to guide the design of the refraction and diffractive hybrid optical system comprising the diffractive optical element.
The measurement of diopter and optical parallax of optical system is preceded traditionally with collimating device or
diopter cylinder, the result of which is influenced largely by subjective operator. In order to increase the pointing
accuracy of the telescope system, a high resolution CCD is adopted and the image of which is processed by computer,
then the result of measurement is outputted by latter. The measuring method which is processed in the paper increase the
degree of accuracy, cancel the influence of subjective factor and simplified the manipulation. Principle of test and
measurement of diopter and optical parallax is represented and computation formula is deduced also. Then, error analysis
of the test and measurement system is presented in the paper.
This measuring machine is specially designed to solve many parameters of crankshaft for some factory. According to the laser slot scanning principle, non-contact measuring of two axes' parallel degree for crankshaft is realized. The machine use laser technique, photoelectric measuring technique, fine mechanical technique, modern photoelectric sensor technique, electronics technique and computer-technique. And the difficulty which include complex shape, large weight, large size, high request of the measured parameter precision and difficult measuring, is solved.
In this paper, present test methods of optical aspherical surfaces are presented. The paper studies mainly a new kind of measurement method of aspherical surfaces-laser wavelength scanning interference test method. This research is aiming at putting forward a wavelength scanning interference test method. Processing and analyzing instantly-read interference patterns corresponding to continuous variable wavelength, the method overcomes the following disadvantages. For example, the longer reference arm, optical measurement environment in big-scale and high-accuracy aspheric testing and sensitive interferometer test system to disturbance, such as the oscillation of worktable, disturbance of air, and so on. Here, the authors describe the principle of elementary design of experiment device, and curtly introduce the method and principle for interference fringe processing. At the same time, this method and interferometric measurement instruments are studied and developed. We can not only perform surface test of high-precision aspheric surface, promote the application of aspheric, but also we can improve the integration of digital image processing, application of CCD and optical test.
The technology on the processing and detection of the extreme ultraviolet radiation and x-ray (EUV/x-ray) optical component is one of the main categories in modern short-wave band optical research. At present, EUV/x-ray optical component are in great demand on the construction of the rapidly developed synchrotron radiant lamp-house and beam of light engineering in developed countries. Now few countries has the ability of developing this kind of optical component with super-smooth surface and high precision and the key technology is processing and detecting technique. In this paper, the author study the measurement method and instrument of the EUV/x-ray optical component, improve the design of the measuring apparatus-long trace profiler LTP already existing, provide a kind of newly long trace profiler LTP-III, which is used to measure slope error.
Fabrication and testing technologies of super-smooth X-ray optical elements of synchrotron radiation is a new field. It works in the short-waveband and is one of the basic contents of optical foundation engineering research of soft X-ray. This article describes optical system characteristics of synchrotron radiation light beam, research goal, significance, background, present situation of our country and comparison with overseas level in fabrication and testing technology of super-smooth synchrotron radiation optical elements. It presents domestic and foreign present situation of super-smooth optical surface fabrication technology, as well as each kind of measurement technologies of synchrotron radiation optical elements. This article relates on fabrication and testing of super-smooth optical elements made of monocrystalline silicon emphatically, systematically introduces fabrication, test method and result of the optical elements. All test results meet with the design specification. The paper also demonstrates the progress approached or achieved both at home and abroad.
Sphere-prism is one of the elements often used in an off axis optical system. Reasonably using a sphere-prism, a series of optical systems with different applications can be designed. These systems have the advantages of small size, less weight and compact structure, and have some optical features which are hardly achieved by a centered optical system, expanding the applications of optical system. In this paper, the technology of making a sphere-prism, a new optical element, is described. At first we make the sphere surface, ans then we make the plane section of a sphere-prism. The professional optical instrument is used to guarantee the angular accuracy in the work of making the plane section. A binocular comparison goniometric angulometer 48°and 90°mater prisms are used to detect the position of spherical center. In the end, a plan that making the spherical section firstly and making the plane section lately is put forward to make sphere-prism. Finally , we give out the fabrication result of the sphere-prism.
Polymer Optics and Molded Glass Optics: Design, Fabrication, and Materials 2022
22 August 2022 | San Diego, California, United States
Advanced Optical Manufacturing Technologies and Applications 2022; and 2nd International Forum of Young Scientists on Advanced Optical Manufacturing (AOMTA and YSAOM 2022)
29 July 2022 | Changchun, China
Sixth Asia Pacific Conference on Optics Manufacture (APCOM2019)
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