FIB machining of occulting masks for imaging of extrasolar planets

Shilpa N. Raja; Michael J. Aziz; James W. Foley; Volker Tolls

doi:10.1117/12.828515

19 August 2009 FIB machining of occulting masks for imaging of extrasolar planets

Shilpa N. Raja, Michael J. Aziz, James W. Foley, Volker Tolls

Proceedings Volume 7440, Techniques and Instrumentation for Detection of Exoplanets IV; 744018 (2009) https://doi.org/10.1117/12.828515
Event: SPIE Optical Engineering + Applications, 2009, San Diego, California, United States

Abstract

We are developing the ability for Focused Ion Beam (FIB) machining of occulting masks for use in coronagraphs. These masks will be used as soft-edged Lyot stops to suppress light from stars and allow direct imaging of extrasolar planets. The FIB approach is attractive because it has the potential for higher precision than mechanical machining and for larger volumes than electron-beam lithography. The mask fabrication process is trifold: 1) a transparent material-currently, poly(methyl methacrylate) (PMMA)-is doped with dyes; 2) the mask shape is FIB milled into the material; and 3) the mask is coated with another layer of index-matching transparent absorber. Using a Zeiss NVision 40 FIB system, we have fabricated conical-shaped masks of various slopes in dye-doped PMMA. Inherent in this process is the advantage of control of the features through programming the ion beam track. We have also optically characterized these masks as well as the dye-doped absorbing material. We have found that the dye-doped PMMA has a very high absorbance, >1 OD.

Citation Download Citation

Shilpa N. Raja, Michael J. Aziz, James W. Foley, and Volker Tolls "FIB machining of occulting masks for imaging of extrasolar planets", Proc. SPIE 7440, Techniques and Instrumentation for Detection of Exoplanets IV, 744018 (19 August 2009); https://doi.org/10.1117/12.828515

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available