Showing papers by "Daniel J. Hoppe published in 2005"
TL;DR: In this paper, the design approaches and performance analysis of the OTA in the wavelength band of interest are described, and the performance at 600nm wavelength based on a particular coating and occulting focal plane mask is also presented.
Abstract: We describe here the design approaches and performance analysis of the OTA in the wavelength band of interest. Coronagraph performance at 600nm wavelength based on a particular coating and occulting focal plane mask is also presented.
17 citations
TL;DR: In this paper, an interferometric apparatus that measures wavefront phase advance/delay through grey-scale and binary masks as functions of wavelength and optical density is presented along with ellipsometric measurements of optical constants.
Abstract: The development of stellar coronagraphs for exoplanet detection requires apodized occulting masks to effectively remove the light from the central star while allowing planet light to propagate past. One possible implementation, a gray-scale mask, includes the placement of micron-scale neutral density light absorbing patterns using High Energy Beam Sensitive (HEBS) glass. A second implementation, binary masks, uses micron-scale diffractive/reflective patterns.
Coronagraph performance will be influenced by wavefront phase shifts introduced by the masks, hence accurate characterization of the fundamental optical properties, namely optical density (OD), phase advance/delay and optical constants of the material is needed for occulter design, development and modeling.
In this paper we describe an interferometric apparatus that measures wavefront phase advance/delay through grey-scale and binary masks as functions of wavelength and optical density, which is also measured. Results for HEBS gray-scale masks will be presented along with ellipsometric measurements of optical constants.
13 citations
TL;DR: In this article, the authors present the results of analysis of random errors and simulate the effects of systematic errors using specific mask designs, and present a simulation of the effect of systematic error on mask design.
Abstract: We present the results of analysis of random errors and simulate the effects of systematic errors using specific mask designs.
6 citations
03 Oct 2005
TL;DR: In this paper, the authors have designed and tested two types of focal plane masks for the Terrestrial Planet Finder Coronagraph (TPF-C) with continuous gray scale profile of the occulting pattern such as 1-sinc2 on a suitable material or with micronscale binary transparent and opaque structures of metallic pattern on glass.
Abstract: Occulting focal plane masks for the Terrestrial Planet Finder Coronagraph (TPF-C) could be designed with continuous gray scale profile of the occulting pattern such as 1-sinc2 on a suitable material or with micron-scale binary transparent and opaque structures of metallic pattern on glass. We have designed, fabricated and tested both kinds of masks. The fundamental characteristics of such masks and initial test results from the High Contrast Imaging Test bed (HCIT) at JPL are presented.
5 citations
01 Oct 2005
Abstract: We describe the baseline TPF-C instrument design as of October 2005.
2 citations
01 Oct 2005
TL;DR: For the past 2 years, NASA has invested substantial resources to study the design and performance of the Terrestrial Planet Finder Coronagraph (TPF-C) as mentioned in this paper, which has achieved 1e-9 contrast in a laboratory experiment.
Abstract: For the past 2 years, NASA has invested substantial resources to study the design and performance of the Terrestrial Planet Finder Coronagraph (TPF-C). The work, led by the Jet Propulsion Laboratory with collaboration from Goddard Space Flight Center and several university and commercial entities, encompasses observatory design, performance modeling, materials characterization, primary mirror studies, and a significant technology development effort including a high-contrast imaging testbed that has achieved 1e-9 contrast in a laboratory experiment.