A set-up based on a special shadow method, pinhole method, was made and some experiments were done. The results show that this novel method is simple, easy to operate,and suitable for testing large aspherical surfaces...A set-up based on a special shadow method, pinhole method, was made and some experiments were done. The results show that this novel method is simple, easy to operate,and suitable for testing large aspherical surfaces quantitatively.展开更多
According to the theory of testing aspherical surface by normal aberration compensation method,the designing method of quasi-universal compensator is studied.On the basis of third-order aberration theory,after calcula...According to the theory of testing aspherical surface by normal aberration compensation method,the designing method of quasi-universal compensator is studied.On the basis of third-order aberration theory,after calculating and optimizing with an optical design program,the structure parameters of a compensator are obtained.This new compensator could be used in Twyman-Green interferometer,and in measurement of a certain range of paraboloid ellipsoid and hyperboloid.The compensation accuracy is more than 0.02 λ .展开更多
By using the derivative method, we obtained the same result with that of the previous work of Chen et al. in 2006. Different from the integral form, the derivative form of the surface expression published in this pape...By using the derivative method, we obtained the same result with that of the previous work of Chen et al. in 2006. Different from the integral form, the derivative form of the surface expression published in this paper is derived from differential equation and based on the theory of non-imaging focusing heliostat proposed by Chen et al. in 2001. The comparison of the derivative form of fixed aberration correction surface has been made with that of integral form surface as well as that of spherical surface in concentrating the solar ray.展开更多
Detailed theoretical investigations into asphericity in the Fermi surface (FS) and Fermi energy (FE) ofNa1_xKx, Na1_xRbx, and Na1_xCsx binary solid solutions are carried out for the first time. The alloying behavior o...Detailed theoretical investigations into asphericity in the Fermi surface (FS) and Fermi energy (FE) ofNa1_xKx, Na1_xRbx, and Na1_xCsx binary solid solutions are carried out for the first time. The alloying behavior ofthe K, Rb, and Cs with the Na generates the Fermi surface distortion (FSD) of bce simple metals. The FS of Na-K,Na-Rb, and Na-Cs solid solution is a distorted sphere with the largest deviation along [110]. We have found that theimpact of local-field correction function on FSD is maximun at [100] point and minimum at [111] point. The exchangeand correlation effect is found to suppress the value of FE.展开更多
In order to improve machining accuracy and efficiency, a software-controlled system of ultra-precision machining for axisymmetric aspheric mirror, using techniques of error compensation, remote transmission and modul...In order to improve machining accuracy and efficiency, a software-controlled system of ultra-precision machining for axisymmetric aspheric mirror, using techniques of error compensation, remote transmission and modularization, is designed based on industrial PC, Windows 2000 work platform and Visual Basic 6.0. By experiments, this system realizes functions of ultra-precision machining, machining error compensation, remote data transmission and automatic data transformation among first machining, compensation machining and accuracy measurement. The actual application shows that error compensation improves machining accuracy, remote transmission improves machining efficiency while modularization avoids repeated work and improves design efficiency. Therefore, the system has met ultra-precision machining need for aspheric mirror.展开更多
A reflective optical system is not affected by chromatic aberration, so it has a wide range of applications. Based on the design theory of reflective zoom system with three mirrors, this paper presents the simulation,...A reflective optical system is not affected by chromatic aberration, so it has a wide range of applications. Based on the design theory of reflective zoom system with three mirrors, this paper presents the simulation, optimiza- tion, and image quality evaluation of the traditional off- axis three-mirror zoom system and freeform off-axis three- mirror reflective zoom system.. In these systems, the optical design was aided by software CODEV. Through the analysis of aberrations and structural performance for the traditional aspherical off-axis three-mirror system, the freeform surface was introduced to the tertiary mirror to improve the balance capacity for optical aberrations. This off-axis three-mirror reflective zoom system based on freeform surface could provide technical reference to the study of such systems.展开更多
The original idea and shaping principle of locus shaping method for processing the aspheric optical parts are introduced, and the partial structure of the machine tool designed is described. The method has the advanta...The original idea and shaping principle of locus shaping method for processing the aspheric optical parts are introduced, and the partial structure of the machine tool designed is described. The method has the advantage of high efficiency and low cost compared to the numerical control method. And it is proven that the method is feasible.展开更多
In this paper, the factors of affecting surface roughness and profiles accuracy of the machined larege depth diamter ratio aspheric surfaces in ultra-precision grinding process are analyzed theoretically. An ultra-pre...In this paper, the factors of affecting surface roughness and profiles accuracy of the machined larege depth diamter ratio aspheric surfaces in ultra-precision grinding process are analyzed theoretically. An ultra-precision aspheric grinding system is then designed and manufactured. Aerostatic form is adopted to build the spindle of the workpiece, transverse guideway, longitudinal guideway and the spindle of the grinder in this system. The following specification is achieved, such as the turning accuracy of the spindle of the workpiece is 0.05 μm, radial rigidity of the spindle is GE 220N/μm, axial rigidity is GE 160 N/μm, radial rigidity of the guideway is GE 200N/μm, the highest rotational speed of the grinder is 80 000 rev/min and its turning accuracy is 0.1 μm, the resolution of linear displacement of the transverse and longitudinal guideway is 4.9 nm. Adjusting range of this adjusting mechanism is 2 mm in the Y direction, the adjusting accuracy of the precise adjusting mechanism is 0.1 μm. Micro displacement measuring system of this ultra-precision aspheric grinding adopts two-backfeed strategy, and angle displacement back-feed is realized by photoelectric encoder, it’s resolution is 655 360 pulse/rev. after 4 frequency multiplication, it’s angle displacement resolution is achieved 2 621 440 pulse/rev. Straight-line displacement is monitored by single frequency laser interferometer (DLSTAX LTM-20B, made in Japan). This CNC system adopts inimitable bi-arc step length flex CN interpolation algorithm, it’s CN system resolution is 5 nm.So this aspheric grinding system ensures profile accuracy of the machined part. The resolution of this interferometer is 5 nm. Finally, lots of ultra-precision grinding experiments are carried out on this grinding system. Some optical aspheric parts, with profiles accuracy of 0.3 μm, surface roughness less than 0.01 μm, are obtained.展开更多
This paper proposes an experimental approach for monitoring and inspection of the formation accuracy in ultra-precision grinding （UPG） with respect to the chatter vibration. Two factors related to the grinding progr...This paper proposes an experimental approach for monitoring and inspection of the formation accuracy in ultra-precision grinding （UPG） with respect to the chatter vibration. Two factors related to the grinding progress, the grinding speed of grinding wheel and spindle, and the oil pressure of the hydrostatic bearing are taken into account to determining the accuracy. In the meantime, a mathematical model of the radius deviation caused by the micro vibration is also established and applied in the experiments. The results show that the accuracy is sensitive to the vibration and the forming accuracy is much improved with proper processing parameters. It is found that the accuracy of aspheric surface can be less than 4 μm when the grinding speed is 1400r/min and the wheel speed is 100 r/min with the oil pressure being 1.1 MPa.展开更多
文摘A set-up based on a special shadow method, pinhole method, was made and some experiments were done. The results show that this novel method is simple, easy to operate,and suitable for testing large aspherical surfaces quantitatively.
文摘According to the theory of testing aspherical surface by normal aberration compensation method,the designing method of quasi-universal compensator is studied.On the basis of third-order aberration theory,after calculating and optimizing with an optical design program,the structure parameters of a compensator are obtained.This new compensator could be used in Twyman-Green interferometer,and in measurement of a certain range of paraboloid ellipsoid and hyperboloid.The compensation accuracy is more than 0.02 λ .
文摘By using the derivative method, we obtained the same result with that of the previous work of Chen et al. in 2006. Different from the integral form, the derivative form of the surface expression published in this paper is derived from differential equation and based on the theory of non-imaging focusing heliostat proposed by Chen et al. in 2001. The comparison of the derivative form of fixed aberration correction surface has been made with that of integral form surface as well as that of spherical surface in concentrating the solar ray.
文摘Detailed theoretical investigations into asphericity in the Fermi surface (FS) and Fermi energy (FE) ofNa1_xKx, Na1_xRbx, and Na1_xCsx binary solid solutions are carried out for the first time. The alloying behavior ofthe K, Rb, and Cs with the Na generates the Fermi surface distortion (FSD) of bce simple metals. The FS of Na-K,Na-Rb, and Na-Cs solid solution is a distorted sphere with the largest deviation along [110]. We have found that theimpact of local-field correction function on FSD is maximun at [100] point and minimum at [111] point. The exchangeand correlation effect is found to suppress the value of FE.
基金This project is supported by National Hi-tech Research and Development Program of China(863 Program, No.2004AA8042111)Program for "IRTXMU".
文摘In order to improve machining accuracy and efficiency, a software-controlled system of ultra-precision machining for axisymmetric aspheric mirror, using techniques of error compensation, remote transmission and modularization, is designed based on industrial PC, Windows 2000 work platform and Visual Basic 6.0. By experiments, this system realizes functions of ultra-precision machining, machining error compensation, remote data transmission and automatic data transformation among first machining, compensation machining and accuracy measurement. The actual application shows that error compensation improves machining accuracy, remote transmission improves machining efficiency while modularization avoids repeated work and improves design efficiency. Therefore, the system has met ultra-precision machining need for aspheric mirror.
文摘A reflective optical system is not affected by chromatic aberration, so it has a wide range of applications. Based on the design theory of reflective zoom system with three mirrors, this paper presents the simulation, optimiza- tion, and image quality evaluation of the traditional off- axis three-mirror zoom system and freeform off-axis three- mirror reflective zoom system.. In these systems, the optical design was aided by software CODEV. Through the analysis of aberrations and structural performance for the traditional aspherical off-axis three-mirror system, the freeform surface was introduced to the tertiary mirror to improve the balance capacity for optical aberrations. This off-axis three-mirror reflective zoom system based on freeform surface could provide technical reference to the study of such systems.
文摘The original idea and shaping principle of locus shaping method for processing the aspheric optical parts are introduced, and the partial structure of the machine tool designed is described. The method has the advantage of high efficiency and low cost compared to the numerical control method. And it is proven that the method is feasible.
文摘In this paper, the factors of affecting surface roughness and profiles accuracy of the machined larege depth diamter ratio aspheric surfaces in ultra-precision grinding process are analyzed theoretically. An ultra-precision aspheric grinding system is then designed and manufactured. Aerostatic form is adopted to build the spindle of the workpiece, transverse guideway, longitudinal guideway and the spindle of the grinder in this system. The following specification is achieved, such as the turning accuracy of the spindle of the workpiece is 0.05 μm, radial rigidity of the spindle is GE 220N/μm, axial rigidity is GE 160 N/μm, radial rigidity of the guideway is GE 200N/μm, the highest rotational speed of the grinder is 80 000 rev/min and its turning accuracy is 0.1 μm, the resolution of linear displacement of the transverse and longitudinal guideway is 4.9 nm. Adjusting range of this adjusting mechanism is 2 mm in the Y direction, the adjusting accuracy of the precise adjusting mechanism is 0.1 μm. Micro displacement measuring system of this ultra-precision aspheric grinding adopts two-backfeed strategy, and angle displacement back-feed is realized by photoelectric encoder, it’s resolution is 655 360 pulse/rev. after 4 frequency multiplication, it’s angle displacement resolution is achieved 2 621 440 pulse/rev. Straight-line displacement is monitored by single frequency laser interferometer (DLSTAX LTM-20B, made in Japan). This CNC system adopts inimitable bi-arc step length flex CN interpolation algorithm, it’s CN system resolution is 5 nm.So this aspheric grinding system ensures profile accuracy of the machined part. The resolution of this interferometer is 5 nm. Finally, lots of ultra-precision grinding experiments are carried out on this grinding system. Some optical aspheric parts, with profiles accuracy of 0.3 μm, surface roughness less than 0.01 μm, are obtained.
文摘This paper proposes an experimental approach for monitoring and inspection of the formation accuracy in ultra-precision grinding （UPG） with respect to the chatter vibration. Two factors related to the grinding progress, the grinding speed of grinding wheel and spindle, and the oil pressure of the hydrostatic bearing are taken into account to determining the accuracy. In the meantime, a mathematical model of the radius deviation caused by the micro vibration is also established and applied in the experiments. The results show that the accuracy is sensitive to the vibration and the forming accuracy is much improved with proper processing parameters. It is found that the accuracy of aspheric surface can be less than 4 μm when the grinding speed is 1400r/min and the wheel speed is 100 r/min with the oil pressure being 1.1 MPa.
