TPF-C Technology Plan - Exoplanet Exploration Program - NASA

Plan for Technology Development
7.4.9 Small Precision Optics
Scope
The key issues for masks are surface roughness, transmitted wavefront, and material
homogeneity. We will fabricate and test substrates that meet the mask PSD requirements with
emphasis on 15-100 micron spatial scales.
For the cube beamsplitters, stress birefringence is identified as the primary limiting factor. Two
approaches will be explored: redesign to eliminate cube beamsplitters and work with
manufacturers to develop techniques and materials for ultralow-stress birefringence.
For the remaining small optics, we will work with manufacturers to obtain 1 nm surface flatness
on mounted optics. The small precision optics have achieved TRL 3.Their schedule is given in
Table 7-10.
Table 7-10. Small Precision Optics Schedule
Planned
Completion
Date
Planned Activities Performance Targets TRL
Pre-Phase A
Work with manufacturers to
define specifications
Set of specifications manufacturers are willing to
attempt
Phase A Build components Substrate meets mask PSD requirements,
1 nm surface flatness for 10-20 cm reflective optics
3
4
119