Near-field microwave phase imaging by a spintronic sensor

We report a novel technique for microwave imaging utilizing a nonlinear coupling between the microwave fields in a ferromagnetic material, in which the relative phase of the coupled microwave fields plays an important role in the resultant homodyne dc voltage. A technical breakthrough has been achieved to effectively control such a relative phase using a spintronic Michelson interferometry. This enables a phase- and amplitude-resolved near-field dielectric image using a spintronic sensor. The contrast of microwave imaging for an object with subwavelength features strongly depends on the local dielectric constant of materials, and agrees well with simulation results by COMSOL.

[2]  Willard S. Boyle.  Nobel Lecture: CCD—An extension of man’s view , 2010 .

[3]  J. Jackson,et al.  Classical Electrodynamics, 2nd Edition , 1975 .

[4]  G. Bridges,et al.  Direct phase probing and mapping via spintronic Michelson interferometry. , 2010, Physical review letters.

[5]  E. Ash,et al.  Super-resolution Aperture Scanning Microscope , 1972, Nature.

[6]  John Melngailis,et al.  Broadband dielectric microwave microscopy on micron length scales. , 2007, The Review of scientific instruments.

[7]  Paul M. Meaney,et al.  Enhancing breast tumor detection with near-field imaging , 2002 .

[8]  Chunrong Song,et al.  A radio frequency device for measurement of minute dielectric property changes in microfluidic channels , 2009 .

[9]  M. Born.  Principles of Optics : Electromagnetic theory of propagation , 1970 .

[10]  Friedrich C. Simmel,et al.  Detection of lipid bilayer and peptide pore formation at gigahertz frequencies , 2006 .

[11]  Steven M. Anlage,et al.  Near‐field scanning microwave microscope with 100 μm resolution , 1996 .

[12]  K. Paulsen,et al.  Initial clinical experience with microwave breast imaging in women with normal mammography. , 2007, Academic radiology.

[13]  Lydia L. Sohn,et al.  Dielectric spectroscopy for bioanalysis: From 40 Hz to 26.5 GHz in a microfabricated wave guide , 2001 .

[14]  G. Smith,et al.  Nobel Lecture: The invention and early history of the CCD , 2010 .

[15]  C.-M. Hu,et al.  Microwave photovoltage and photoresistance effects in ferromagnetic microstrips , 2007, 0710.1974.