Phase Discontinuities and Phase

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Phase Discontinuities and Phase
Andrew G. Peele

• P. J. McMahon, D. Paterson, C. Q. Tran, A.
  Mancuso, T. R. Mackin, K. A. Nugent

University of Melbourne
APS, Argonne National Laboratory
B. Lai, I. McNulty
IRIS, Swinburne University of Technology
J. P. Hayes, E. Harvey
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Outline

• Motivation
• Vortices
• Description
• Manufacture
• Propagation
• Diagnostics
• Experimental Results
• Preview of Phase Recovery Methods

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Motivation
Phase Motivation

• Investigating pathological conditions where phase
  retrieval methods break down.

? Phase vortex structures
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Description
Phase
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Motivation
Vortex Motivation

• Visible
• Optical Spanner
• Waveguide for Atom Optics
• Tool to create a waveguide in a non-linear
  material for optical computing
• Analogy for study of vortex effects in other
  media (superfluids, hurricanes, superconductors)

• X-Ray
• Structured focus for high resolution imaging
• Nulling method for astronomy or synchrotron
  studies
• non-diffracting beams (lithography)
• Impart orbital angular momentum via k-shell
  interactions???

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Manufacture
t2? d/? n 1 d iß
Energy (keV)
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Excimer Laser Mask Projection
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Beam Uniformity
Homogeniser output 5 RMS 8 x 8 mm
Laser Output
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Depth Calibration
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Mask
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Spiral Phaseplate
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Propagation
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Propagation
m - integer
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Propagation
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Non-integer charge?
Anger Function
m - integer
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Diagnostics
OR
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Diagnostics
Simple
Full
Numerical
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X-ray Experiment
Crystal scintillator
X-rays
Spiral phaseplate
CCD camera
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Intensity
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Diagnostic Experiment
Crystal scintillator
Tungsten Wire
X-rays
Spiral phaseplate
CCD camera
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Diffraction/Interference Pattern
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High and Intermediate Charge Vortices
Full
Numerical
Simple
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High and Intermediate Charge Vortices
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High and Intermediate Charge Vortices
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High and Intermediate Charge Vortices
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Phasing Vortices
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Phasing Vortices
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Phasing Vortices
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Phasing Vortices
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Conclusions

• Have fabricated spiral phaseplate
• Diagnostic fitting shows (1.8 0.2)?
• And other charges up to charge 4
• Theoretical and simulational work demonstrates
  phase retrieval of vortices
• Next experiments!