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Testing and calibration of phase plates for jwst optical simulator
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Eichhorn, William Chu, Jenny Gong, Qian Kubalak, David Tournois, Severine |
| Copyright Year | 2011 |
| Description | Three phase plates were designed to simulate the JWST segmented primary mirror wavefront at three on-orbit alignment stages: coarse phasing, intermediate phasing, and fine phasing. The purpose is to verify JWST's on-orbit wavefront sensing capability. Amongst the three stages, coarse alignment is defined to have piston error between adjacent segments being 30 m to 300 m, intermediate being 0.4 m to 10 m, and fine is below 0.4 m. The phase plates were made of fused silica, and were assembled in JWST Optical Simulator (OSIM). The piston difference was realized by the thickness difference of two adjacent segments. The two important parameters to phase plates are piston and wavefront errors. Dispersed Fringe Sensor (DFS) method was used for initial coarse piston evaluation, which is the emphasis of this paper. Point Diffraction Interferometer (PDI) is used for fine piston and wavefront error. In order to remove piston's 2 pi uncertainty with PDI, three laser wavelengths, 640nm, 660nm, and 780nm, are used for the measurement. The DHS test setup, analysis algorithm and results are presented. The phase plate design concept and its application (i.e. verifying the JWST on-orbit alignment algorithm) are described. The layout of JWST OSIM and the function of phase plates in OSIM are also addressed briefly. |
| File Size | 578591 |
| Page Count | 14 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_20110015240 |
| Archival Resource Key | ark:/13960/t7mq01b9s |
| Language | English |
| Publisher Date | 2011-08-21 |
| Access Restriction | Open |
| Subject Keyword | Optics Silica Glass Thickness James Webb Space Telescope Errors Alignment Layouts Calibrating Simulators Detection Segmented Mirrors Wave Fronts Interferometers Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Article |
