Phase-reversal zone plates can be designed even for regions of the electromagnetic spectrum where the index of refraction is complex, with a real part close to 1.0. These devices are superior to Fresnel zone plates both in their light collection, and in their signal-to-noise characteristics. Materials with suitable optical and mechanical properties exist throughout most of the 1–800-Å wavelength range for their construction. Imperfections in fabrication, such as incorrect plate thickness, sloping zone edges, or an error in the width of alternate zones result in only moderate deterioration in optical performance.
You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.
You do not have subscription access to this journal. Figure files are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.
You do not have subscription access to this journal. Article tables are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.
You do not have subscription access to this journal. Equations are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.
Flux in first- and higher-order real images and their sum in units of the incident flux. Virtual images have identical fluxes.
Including virtual images.
Sinusoidal amplitude-transmittance variation.
The amplitude of phase modulation for maximum first-order irradiance, ϕmax = 1.84 radians (peak to peak), is assumed.
Table II
Optical properties of materials for zone-plate construction.a
Uncertainties of δ are typically ±15%, of k±10–40%.
Thickness for maximum image flux.
To find δ from Eq. (11), we used Zeff = Z for λ below the K edge, Zeff = Z − 2 above.
Be is probably suitable in the 130–300-Å range, although no consistent set of optical constants has been found in the literature for this wavelength interval.
These values correspond to pure aluminum. For material with oxidized surfaces, they have to be increased by a factor of about 1.6–1.8.
Flux in first- and higher-order real images and their sum in units of the incident flux. Virtual images have identical fluxes.
Including virtual images.
Sinusoidal amplitude-transmittance variation.
The amplitude of phase modulation for maximum first-order irradiance, ϕmax = 1.84 radians (peak to peak), is assumed.
Table II
Optical properties of materials for zone-plate construction.a
Uncertainties of δ are typically ±15%, of k±10–40%.
Thickness for maximum image flux.
To find δ from Eq. (11), we used Zeff = Z for λ below the K edge, Zeff = Z − 2 above.
Be is probably suitable in the 130–300-Å range, although no consistent set of optical constants has been found in the literature for this wavelength interval.
These values correspond to pure aluminum. For material with oxidized surfaces, they have to be increased by a factor of about 1.6–1.8.