All approaches to starlight suppression are subject to spectral bandpass limitations. For nulling interferometers (“nullers”), the issue lies in achieving broadband symmetry between destructively interfering beams. In this effort we propose to improve upon the use of Fresnel rhombs as achromatic phase shifters (APS) for broadband high contrast nulling interferometry by adding dielectric coatings to each rhomb. These components will be characterized along with a fiber bundle spatial filter array (SFA) that is used for complex wavefront control. These components (the APS and SFA) are used in parallel to ultimately reach contrasts needed for Earth-like exoplanet detection.
The objectives of this project include 1) designing and tolerancing a new set of coated Fresnel rhomb APS that will, in theory, improve broadband peformance by over two orders of magnitude compared to a previous generation set of APS, 2) procuring one or more symmetric sets of APS and fabricating new mounting hardware, and 3) measuring and verifying the performance of the APS. The end goal or product is to produce an enhanced set of optics that improve the performance of the current, uncoated APS rhombs by two to three orders of magnitude, for use in testing with future demonstrations of the Segmented Aperture Interferometric Nulling Testbed (SAINT), which uses the Visible Nulling Coronagraph (VNC) for high-contrast source suppression. This is a technology maturation effort for missions such as the Habitable Exoplanet Imager (HabEx) or a future large aperture UV/Optical/IR telescope (LUVOIR) Surveyor. The innovative elements include a fabrication scheme that yields symmetric optics, and a test regiment that can measure prism angles with sub-arcsecond precision and retardance to micro-radian precision.More »
This technology will benefit future missions that seek to use nulling interferometry for high-contrast imaging applications such as exoplanet detection and characterization.More »
The purpose of the Goddard Space Flight Center’s Internal Research and Development (IRAD) program is to support new technology development and to address scientific challenges. Each year, Principal Investigators (PIs) submit IRAD proposals and compete for funding for their development projects. Goddard’s IRAD program supports eight Lines of Business: Astrophysics; Communications and Navigation; Cross-Cutting Technology and Capabilities; Earth Science; Heliophysics; Planetary Science; Science Small Satellites Technology; and Suborbital Platforms and Range Services.
Task progress is evaluated twice a year at the Mid-term IRAD review and the end of the year. When the funding period has ended, the PIs compete again for IRAD funding or seek new sources of development and research funding or agree to external partnerships and collaborations. In some cases, when the development work has reached the appropriate Technology Readiness Level (TRL) level, the product is integrated into an actual NASA mission or used to support other government agencies. The technology may also be licensed out to the industry.
The completion of a project does not necessarily indicate that the development work has stopped. The work could potentially continue in the future as a follow-on IRAD; or used in collaboration or partnership with Academia, Industry and other Government Agencies.
If you are interested in partnering with NASA, see the TechPort Partnerships documentation available on the TechPort Help tab. http://techport.nasa.gov/helpMore »
|Organizations Performing Work||Role||Type||Location|
|Goddard Space Flight Center (GSFC)||Lead Organization||NASA Center||Greenbelt, MD|