In this Letter, a three-parameter modified Kaiser apodization window is used to modulate the pinhole density on each ring of hard x-ray photon sieves, analyzing the guided-wave propagation inside the photon sieves’ nanostructure. Theoretical analysis reveals that the waveguide effect can suppress the emergence of the high-order diffraction effect; the additional parameter of the modified Kaiser window function gives rise to new degrees of freedom for manipulating the FWHM and signal-to-noise ratio. Metal nanostructure thickness has no influence on the FWHM. Hard x-ray photon sieves with 90° phase shift (not 180° phase shift) can provide the best signal-to-noise ratio, which relaxes the nanofabrication constraints somewhat. Our work provides a robust way to design hard x-ray photon sieves.
© 2009 Optical Society of America
Original Manuscript: July 8, 2009
Revised Manuscript: August 14, 2009
Manuscript Accepted: August 24, 2009
Published: September 30, 2009
Changqing Xie, Xiaoli Zhu, and Jia Jia, "Focusing properties of hard x-ray photon sieves: three-parameter apodization window and waveguide effect," Opt. Lett. 34, 3038-3040 (2009)