Optical Vectorial Vortex Coronagraphs using Liquid Crystal Polymers: theory, manufacturing and laboratory demonstration.

In this paper, after briefly reviewing the theory of vectorial vortices, we describe our technological approach to generating the necessary phase helix, and report results obtained with the first optical vectorial vortex coronagraph (OVVC) in the laboratory. To implement the geometrical phase ramp, we make use of Liquid Crystal Polymers (LCP), which we believe to be the most efficient technological path to quickly synthesize optical vectorial vortices of virtually any topological charge. With the first prototype device of topological charge 2, a maximum peak-to-peak attenuation of 1.4x10(-2) and a residual light level of 3x10(-5) at an angular separation of 3.5 lambda/d (at which point our current noise floor is reached) have been obtained at a wavelength of 1.55 microm. These results demonstrate the validity of using space-variant birefringence distributions to generate a new family of coronagraphs usable in natural unpolarized light, opening a path to high performance coronagraphs that are achromatic and have low-sensitivity to low-order wavefront aberrations.

[1]  M. Berry.  The Adiabatic Phase and Pancharatnam's Phase for Polarized Light , 1987 .

[2]  Russell A. Chipman,et al.  Mueller matrix imaging polarimetry: an overview , 1996, Other Conferences.

[3]  Grover A. Swartzlander,et al.  Propagation dynamics of optical vortices , 1997 .

[4]  A. Labeyrie,et al.  The Four-Quadrant Phase-Mask Coronagraph. I. Principle , 2000 .

[5]  Erez Hasman,et al.  Polarization Talbot self-imaging with computer-generated, space-variant subwavelength dielectric gratings. , 2002, Applied optics.

[6]  Optical vortex coronagraphs , 2004 .

[7]  D. Mawet,et al.  Annular Groove Phase Mask Coronagraph , 2005 .

[8]  D. Mawet,et al.  Subwavelength surface-relief gratings for stellar coronagraphy. , 2005, Applied optics.

[9]  Eugene Serabyn,et al.  An off-axis four-quadrant phase-mask coronagraph for Palomar: high contrast near bright stars imager , 2005, SPIE Optics + Photonics.

[10]  G. Biener,et al.  Space-variant polarization manipulation for far-field polarimetry by use of subwavelength dielectric gratings. , 2005, Optics letters.

[11]  G. Swartzlander,et al.  Optical vortex coronagraph. , 2005, Optics letters.

[12]  S. Ridgway,et al.  Theoretical Limits on Extrasolar Terrestrial Planet Detection with Coronagraphs , 2006, astro-ph/0608506.

[13]  Pierre Baudoz,et al.  The four-quadrant phase-mask coronagraph : white light laboratory results with an achromatic device , 2006 .

[14]  Erez Hasman,et al.  Manipulation of polarization-dependent multivortices with quasi-periodic subwavelength structures. , 2006, Optics letters.

[15]  Richard Dekany,et al.  PALM-3000: visible light AO on the 5.1-meter Telescope , 2006, SPIE Astronomical Telescopes + Instrumentation.

[16]  Erez Hasman,et al.  Space-variant polarization scrambling for image encryption obtained with subwavelength gratings , 2006 .

[17]  Erez Hasman,et al.  Manipulation of the Pancharatnam phase in vectorial vortices. , 2006, Optics express.

[18]  C. Fabron,et al.  SPHERE: a planet finder instrument for the VLT , 2006, Astronomical Telescopes + Instrumentation.

[19]  Shane Jacobson,et al.  Concept and science of HiCIAO: high contrast instrument for the Subaru next generation adaptive optics , 2006, SPIE Astronomical Telescopes + Instrumentation.

[20]  Annular Groove Phase Mask: An Achromatic Vortex Coronagraph Intended at Differential Polarimetric Imaging , 2007 .

[21]  Pierre Baudoz,et al.  The Four Quadrant Phase Mask Coronagraph and its avatars , 2007 .

[22]  Erez Hasman,et al.  Polychromatic vectorial vortex formed by geometric phase elements. , 2007, Optics letters.

[23]  John E. Krist,et al.  PROPER: an optical propagation library for IDL , 2007, SPIE Optical Engineering + Applications.

[24]  Brian J. Bauman,et al.  Adaptive Optics for Direct Detection of Extrasolar Planets: The Gemini Planet Imager , 2007 .

[25]  E. Serabyn,et al.  EXTREME ADAPTIVE OPTICS IMAGING WITH A CLEAR AND WELL-CORRECTED OFF-AXIS TELESCOPE SUBAPERTURE , 2007, astro-ph/0702592.

[26]  Kjetil Dohlen,et al.  Prototyping coronagraphs for exoplanet characterization with SPHERE , 2008, Astronomical Telescopes + Instrumentation.

[27]  Daniel W. Wilson,et al.  Astronomical demonstration of an optical vortex coronagraph. , 2008 .

[28]  David M. Shemo,et al.  Vortex retarders produced from photo-aligned liquid crystal polymers. , 2008, Optics express.

[29]  Russell A Chipman,et al.  Creating vortex retarders using photoaligned liquid crystal polymers. , 2008, Optics letters.

[30]  Laird M. Close,et al.  Contrast Enhancement of Binary Star System Using an Optical Vortex Coronagraph , 2008 .