Abstract
A multi-aperture atmospheric pressure plasma processing (APPP) method was proposed to structure the continuous phase plate (CPP). The APPP system was presented and removal investigation showed the removal function of APPP was of a high repeatability and robustness to the small disturbance of gas flows. A mathematical model for the multi-aperture structuring process was established and the simulation analysis indicated the advantages of the proposed method in terms of balancing the efficiency and accuracy of the process. The experimental results showed that multi-aperture APPP has the ability to structure a 30 mm × 30 mm CPP with the accuracy of 163.4 nm peak to valley (PV) and 31.7 nm root mean square (RMS).
Highlights
Continuous phase plates (CPPs) are essential diffractive optical elements in the light path of laser-driven inertial confinement fusion (ICF) systems, such as the National Ignition Facility [1], Laser Megajoule [2] and the SG-III laser facility [3]
Magnetorheological finishing (MRF) has been used to fabricate large-aperture CPPs [5], in which the spatial periods of microstructures are usually larger than 4 mm, and the peak to valley (PV) of the structure height is as large as several microns
Taking both the CPP structuring efficiency and accuracy into account, this study proposed a multi-aperture optimized structuring method, where multiple removal functions were considered, and the corresponding dwell time was simultaneously solved in one optimization process
Summary
Continuous phase plates (CPPs) are essential diffractive optical elements in the light path of laser-driven inertial confinement fusion (ICF) systems, such as the National Ignition Facility [1], Laser Megajoule [2] and the SG-III laser facility [3]. APPP has received a great deal of interest in optical fabrication because of its deterministic high material removal rate, controlled millimeter tool spot, and no subsurface damage. It is based on pure chemical reactions between the surface atoms of silicon-based materials and reactive fluorine radicals generated by the plasma at atmospheric pressure, which avoids the introduction of damage to the processed surface and significantly lowers the processing cost. The stable and controllable Gaussian-shape removal function makes APPP possible to fabricate structured surfaces with high accuracy and efficiency. Multi-aperture processing (with multiple-scale removal functions) is enabled to target different scales of surface features to increase the overall machining efficiency.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
