Tilted gratings and method for production of tilted gratings
AssigneeKoninklijke Philips Electronics N.V.
InventorsGereon Vogtmeier, Klaus Juergen Engel, Thomas Koehler, Ewald Roessl
Life of this patent
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Abstract
The present invention relates to phase-contrast imaging which visualizes the phase information of coherent radiation passing a scanned object. Focused gratings are used which reduce the creation of trapezoid profile in a projection with a particular angle to the optical axis. A laser supported method is used in combination with a dedicating etching process for creating such focused grating structures.
Claims15
Method of fabricating a grating (100) for a phase contrast imaging apparatus for examining an object of interest, the grating (100) having a primary axis which is arranged in a direction towards a source of radiation when the grating is installed in the imaging apparatus, the method comprising the steps of:
- writing, with a beam of electromagnetic radiation, at least a first trench (101) into a wafer material;
- smoothing surfaces of the written first trench by etching technology;
- wherein the first trench (101) has a depth in a first direction;
- wherein the first direction is different from the primary axis, such that the first trench (101) is tilted by a first angle with respect to the primary axis.
A grating for a phase contrast imaging apparatus for examining an object of interest, the grating (100) having a primary axis which is arranged in a direction towards a source of radiation when the grating (100) is installed in the imaging apparatus, the grating (100) comprising:
- a wafer material (701);
- a first trench (101) inside the wafer material (701) and having a depth in a first direction;
- wherein the first direction is different from the primary axis, such that the first trench (101) is tilted with respect to the primary axis.
A phase contrast imaging apparatus for examining an object of interest, the apparatus (400) comprising:
- a source (401) for emitting a beam of radiation;
- a detector (402);
- a grating (100, 200) positioned between the source (401) and the detector (402);
- wherein the detector (402) is adapted for detecting the radiation after it has passed the object of interest (403) and the grating (100, 200);
- wherein the grating (100, 200) has a focused geometry;
- wherein the grating (100, 200) has a primary axis which is arranged in a direction towards a source of radiation when the grating is installed in the imaging apparatus, the grating comprising:
- a wafer material (701);
- a first trench (101) inside the wafer material (701) and having a depth in a first direction;
- wherein the first direction is different from the primary axis, such that the first trench (101) is tilted with respect to the primary axis.
Dependencies are inferred from the claim text.