Fresnel Zone Plate Lenses
Xradia is offering high-efficiency zone plate lenses for X-ray imaging and microfocusing applications. These high-resolution zone plates are employed in Xradia's award winning TXM-line of high-resolution x-ray imaging tomography systems and in synchrotron radiation facilities around the world.
High Resolution
Zone plates use constructive interference of light rays from adjacent zones to form a focus (figure below). The focal length f of a zone plate is a function of its diameter OD, its outermost zone width ΔRn and the x-ray wavelength λ:
f = ODΔRn / λ
The resolution of a zone plate is limited to 1.22 ΔRn (Raleigh criterion) requiring narrow zones for best performance. Xradia is fabricating zone widths as narrow as 30 nm for high-resolution applications.
High Efficiency
To achieve the best focusing efficiency for hard x-rays, Xradia is using gold for the zone construction material. A special lithography process has been developed to fabricate high aspect ratio gold structures on freestanding silicon nitride membranes.
With the proper choice of gold zone thickness, high-resolution zone plates with high efficiency can be made covering the x-ray energy range from 0.2 – 60 keV (figure below).
Theoretical efficiency of zone plate lenses with different thickness
Custom Design
In addition to its lineup of gold zone plates, Xradia offers customized diffractive optics for your application including test structures for resolution tests. Please inquire about pricing for your design and custom zone construction materials. Xradia is proud to offer a wide range of zone plate lens designs. They offer the best performance in terms of spatial resolution and focusing efficiency for 1- 20 keV x-rays.
Commitment to Quality
Each zone plate is fully characterized as to fabrication parameters, efficiency and resolution. The typical focusing efficiency will be greater than 50% of the value calculated using the focusing efficiency calculation program on the CXRO web page.
Zone Plate Holder
Xradia supplies zone plates on a specially designed stainless steel mounting cone as pictured below. The holder provides a convenient working space for most micro-beam and imaging applications and a safe and robust handling of the zone plate. Xradia also supplies zone plates un-mounted or mounted on a customer supplied mount.
Fresnel Zone Plates
Specifications And Price Information
(revised May 1, 2006)
| Model | Parameters |
|||||||
Zone Material |
ΔRn |
D |
N |
Tm |
Erange |
ηmax |
Emax(keV) |
|
ZP30-80-1 |
Gold |
30 |
80 |
667 |
150 |
0.13-1.4 |
12 |
0.8 |
ZP30-160-1 |
Gold |
30 |
160 |
1333 |
150 |
0.13-1.4 |
12 |
0.8 |
ZP40-80-1 |
Gold |
40 |
80 |
500 |
150 |
0.13-1.4 |
12 |
0.8 |
ZP40-160-1 |
Gold |
40 |
160 |
1000 |
150 |
0.13-1.4 |
12 |
0.8 |
ZP40-400-1 |
Gold |
40 |
400 |
2500 |
150 |
0.13-1.4 |
12 |
0.8 |
| ZP54-4444-1 | Gold |
54 |
4444 |
20500 |
150 |
0.13-1.4 |
12 |
0.8 |
ZP150-2000-1 |
Gold |
150 |
2000 |
3330 |
150 |
0.13-1.4 |
12 |
0.8 |
ZP30-80-4 |
Gold |
30 |
80 |
667 |
450 |
1 - 6 |
23 |
1.8 |
| ZP40-80-4 | Gold |
40 |
80 |
500 |
450 |
1 - 6 |
23 |
1.8 |
| ZP50-80-4 | Gold |
50 |
80 |
400 |
450 |
1 - 6 |
23 |
1.8 |
| ZP50-160-4 | Gold |
50 |
160 |
800 |
450 |
1 - 6 |
23 |
1.8 |
| ZP50-80-7 | Gold |
50 |
80 |
400 |
700 |
2 - 9 |
21 |
4.7 |
| ZP50-160-7 | Gold |
50 |
160 |
800 |
700 |
2 - 9 |
21 |
4.7 |
| ZP70-160-7 | Gold |
70 |
160 |
571 |
700 |
2 - 9 |
21 |
4.7 |
| ZP100-160-16 | Gold |
100 |
160 |
400 |
1600 |
5 - 24 |
31 |
9 |
| ZP100-320-16 | Gold |
100 |
320 |
800 |
1600 |
5 - 24 |
31 |
9 |
| ZP100-4000-16 | Gold |
100 |
4000 |
10000 |
1600 |
5 - 24 |
31 |
9 |
| ZP100-1000-16 | Gold |
100 |
1000 |
2500 |
1600 |
5 - 24 |
31 |
9 |
Parameters:
ΔRn: outermost zone width (Rayleigh resolution of lens = 1.22 ΔRn)
D: diameter
N: total number of Fresnel Zones (half period)
Tm: thickness of zone construction material
E range: energy range with theoretical focusing efficiency greater than 10%
ηmax: maximum theoretical focusing efficiency (achieved at energy Emax)
Emax: energy at which maximum focusing efficiency ηmax is achieved
Siemens Star Test Patterns
Parameters |
||||
| Model | Smallest Feature Size |
Diameter of Siemens star |
Tm |
Zone Material |
X30-30-1 |
30 |
30 |
150 |
Gold |
X500-200-30 |
500 |
200 |
30000 |
Gold |
Notes: Zone plates and test patterns are fabricated on a free standing, low stress Si3N4 membrane with a thickness of 100-120 nm for Gold and Nickel zone plates up to 200 nm in thickness, 250-300 nm for multi-keV Gold zone plates, and 1000 nm for hard x-ray Gold zone plates. Xradia delivers zone plates with a focusing efficiency exceeding 50% of the theoretically calculated value. Delivery is 4 month ARO for standard zone plates not stocked and 4 month ARO for custom zone plates.
* For pricing and shipment please kindly contact us at sales@xradia.com or call 925-288-1228 ext 1114.
