Efficient testing of segmented aspherical mirrors by use of a reference plate and computer-generated holograms. II. Case study, error analysis, and experimental validation
Feenix Y. Pan, Jim Burge, Dave Anderson, and Alexander Poleshchuk
Feenix Y. Pan, Jim Burge, Dave Anderson, and Alexander Poleshchuk, "Efficient testing of segmented aspherical mirrors by use of a reference plate and computer-generated holograms. II. Case study, error analysis, and experimental validation," Appl. Opt. 43, 5313-5322 (2004)
Segmented mirrors present unique challenges to fabrication and testing that are absent for monolithic optics. Since traditional asphere tests do not address segmented optics adequately, we validate a previously developed method to test large quantities of segments accurately, quickly, and economically. In this test, the aspheric shape of each segment is controlled to high accuracy by use of computer-generated holograms, and the radius of curvature is tightly controlled by use of the reference plate. In an adjoining paper [Appl Opt 43, 5303 (2004)] we developed the theory for this test, and now we present a complete system design and optimization for measuring the 1.4-m segments from a 30-m F/1 primary. A complete tolerance analysis predicts a test accuracy of 4.8-nm rms surface and excellent accuracy for controlling the geometry of the segment. In addition, a laboratory demonstration using 30-cm optics is presented that demonstrated 3.9-nm rms surface accuracy.
You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.
You do not have subscription access to this journal. Figure files are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.
You do not have subscription access to this journal. Article tables are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.
You do not have subscription access to this journal. Equations are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.
give hologram size of 33.5 mm in diameter with 15-μm nominal spacingb
for the farthest-out segment (Fig.
3).
If these holograms are made onto a 150 mm × 150 mm substrate, we estimate that to test all 103 optically unique segments with six substrates would cost a total of under $45,000.
Table 2
Figure Error Budget for Test of the T13 Segment (the Most Difficult)a
give hologram size of 33.5 mm in diameter with 15-μm nominal spacingb
for the farthest-out segment (Fig.
3).
If these holograms are made onto a 150 mm × 150 mm substrate, we estimate that to test all 103 optically unique segments with six substrates would cost a total of under $45,000.
Table 2
Figure Error Budget for Test of the T13 Segment (the Most Difficult)a
Add to BibSonomy