In order to solve the problem that the extra removal layer and the motion characteristics of the machine tool are difficult to meet the processing requirements of ion beam figuring, an ion beam figuring method based on new controllable ion source is proposed. By changing the working parameters of the ion optical system, the timing and duration of ion beam extraction are controlled in real time. The influence law of the machine tool motion acceleration in the process is analyzed theoretically, and then a new ion beam figuring method is proposed for the lack of dynamic performance. By adjusting the working parameters of the ion source developed by ourselves, the pulse duty ratio is continuously adjustable from 0 to 100% , and the pulse frequency is continuously adjustable from 1 to 1000 Hz. The sample is Φ100 mm monocrystalline silicon plane mirror. Firstly, the long-time stability of the new ion source was verified by line- scanning experiments, and then the error of 14.5 mm wavelength was etched with the axis of motion at a constant speed. The results show that the technology can make up for the lack of motion acceleration and avoid the extra removal layer, and have a wide range of potential applications in high precision quality adjustment, special surface treatment and so on. It is expected to promote the progress of ultra-precision machining technology.
Ion beam figuring has the advantages of non-contact, high certainty, and removal function’s long-term stability. It is the primary processing method of ultra-high precision optical elements such as lithography objective lens. In general, the IBF process does not require high motion precision of the moving mechanism. However, when the shape of the optical components changes from a plane to a curved surface and the RMS value of the surface accuracy is better than 0.3nm, the influence of the motion accuracy cannot be ignored. The paper focuses on the influence mechanism of IBF equipment’s motion accuracy on the shape of removal function, removal rate, and other essential parameters under the three-axis figuring mode of curved surface elements. We have discussed the sub-nanometer precision generation requirements of curved elements for removal function positioning accuracy and motion accuracy of polishing equipment. The feasibility of ion beam triaxial machining for the sub-nanometer precision generation of curved optical elements is demonstrated by analysis and calculation. The results show that under the condition of ensuring the micron motion accuracy, the three-axis ion beam figuring equipment can also process the curved surface’s surface to the ultra-high precision that the RMS value is better than 0.3nm. Still, it is difficult to achieve the machining goal only by improving the motion precision of the machine tool’s motion axis, so it is necessary to control the components’ initial profile error.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.