Imager optical systems and methods
Techniques are disclosed for optical imager devices, systems, and methods. In one example, an imaging system includes a focal plane array (FPA) and a light shield. The FPA includes a detector array configured to detect a first portion of electromagnetic radiation and generate a detector signal based on the first portion. The FPA further includes a readout circuit coupled to the detector array and configured to receive the detector signal. The light shield is coupled to the FPA and configured to block a second portion of the electromagnetic radiation. Related devices and methods are also provided.
1. An imaging system comprising:
a focal plane array (FPA) comprising:
a detector array configured to detect a first portion of electromagnetic radiation and generate a detector signal based on the first portion; and
a readout circuit coupled to the detector array and configured to receive the detector signal; and
a first light shield coupled to the FPA and configured to block a second portion of the electromagnetic radiation, wherein the first light shield comprises:
a leg configured to couple to the FPA; and
a wall extending from the leg.
2. The imaging system of claim 1 , further comprising a second light shield disposed over a portion of the detector array and a portion of the first light shield, wherein the second light shield is configured to block a third portion of the electromagnetic radiation.
3. The imaging system of claim 1 , wherein the first light shield forms a continuous perimeter around the detector array and is configured to block the second portion by absorbing the second portion, and wherein a waveband associated with the first portion overlaps at least a portion of a waveband associated with the second portion.
4. An imaging system comprising:
a focal plane array (FPA) comprising:
a detector array configured to detect a first portion of electromagnetic radiation and generate a detector signal based on the first portion; and
a readout circuit coupled to the detector array and configured to receive the detector signal;
a first light shield coupled to the FPA and configured to block a second portion of the electromagnetic radiation, wherein the first light shield forms a continuous perimeter around the detector array and is configured to block the second portion by absorbing the second portion, and wherein a waveband associated with the first portion overlaps at least a portion of a waveband associated with the second portion;
a vacuum package housing, wherein the FPA and the first light shield are enclosed in the vacuum package housing; and
a second light shield enclosed in the vacuum package housing and disposed over a portion of the detector array and a portion of the first light shield, wherein the second light shield is configured to block a third portion of the electromagnetic radiation.
5. The imaging system of claim 1 , wherein the second portion comprises a portion of the electromagnetic radiation directed to an edge of the detector array, and wherein a portion of the first light shield extends over a vertical edge of the detector array.
6. The imaging system of claim 4 , wherein the first light shield comprises:
a leg configured to couple to the FPA; and
a wall extending from the leg.
7. The imaging system of claim 1 , further comprising a plurality of additional legs, wherein the leg is a first leg, wherein the first leg and each of the plurality of additional legs is coupled to the readout circuit, and wherein a height of the first light shield is greater than a height of the detector array.
8. The imaging system of claim 1 , wherein the FPA further comprises a bond pad, wherein a thickness of the leg is less than a distance between an edge of the detector array and the bond pad, and wherein the wall has a T-shaped or an L-shaped cross-section.
9. The imaging system of claim 1 , wherein the first light shield further comprises at least one alignment element extending from the wall and configured to align an optical element with the detector array.
10. The imaging system of claim 9 , wherein the at least one alignment element comprises at least three alignment elements, and wherein the first light shield is configured to form a continuous perimeter around the detector array.
11. The imaging system of claim 9 , further comprising the optical element coupled to the at least one alignment element and the wall, wherein the optical element is configured to filter a third portion of the electromagnetic radiation to obtain the first portion.
12. The imaging system of claim 11 , further comprising a window disposed over the optical element, wherein a portion of the wall is configured to extend over a vertical edge of the detector array, and wherein interior surfaces of a portion of the first light shield face exterior surfaces of the detector array.
13. A method of manufacturing the imaging system of claim 1 , the method comprising:
providing the FPA; and
coupling the first light shield to the FPA such that interior surfaces of a portion of the first light shield face exterior surfaces of the detector array.
14. The method of claim 13 , further comprising:
disposing the FPA and the first light shield within a package assembly; and
coupling a second light shield to the package assembly, wherein the second light shield is disposed over a portion of the detector array and a portion of the first light shield, and wherein the second light shield is configured to block a third portion of the electromagnetic radiation.
15. The method of claim 14 , further comprising coupling, using at least one alignment element of the first light shield, an optical element to the package assembly to align the optical element with the detector array.
16. A method comprising:
detecting, by a focal plane array that comprises a detector array and a readout circuit, a first portion of electromagnetic radiation;
generating, by the focal plane array, a detector signal based on the first portion; and
blocking, by a first light shield coupled to the focal plane array, a second portion of the electromagnetic radiation from the detector array by absorbing the second portion, wherein the first light shield comprises:
a leg in contact with the readout circuit; and
a wall extending from the leg.
17. The method of claim 16 , further comprising filtering, by an optical element coupled to the first light shield, a third portion of the electromagnetic radiation to obtain the first portion of the electromagnetic radiation.
18. The method of claim 17 , wherein the optical element is coupled to the first light shield using at least one alignment element of the first light shield.
19. The method of claim 18 , wherein:
the second portion comprises a portion of the electromagnetic radiation directed to an edge of the detector array;
a portion of the wall extends over a vertical edge of the detector array; and
the first light shield further comprises:
the at least one alignment element extending from the wall and configured to align the optical element with the detector array.
20. The method of claim 16 , further comprising blocking, by a second light shield, a third portion of the electromagnetic radiation from the detector array by scattering the third portion, wherein the second light shield is disposed over a portion of the detector array and a portion of the first light shield.