Broadband graphene-based optical limiter for the protection of backside illuminated CMOS detectors
An optical device may include a sacrificial limiter filter including at least one layer of graphene disposed on a substrate. The at least one layer of graphene may be configured to absorb and scatter at least a portion of electromagnetic radiation incident on the at least one layer of graphene.
1. An optical device that is operative in response to electromagnetic radiation in a predefined spectral range and disabled in response to laser radiation exceeding a predefined damage threshold, the optical device comprising:
a substrate; and
a sacrificial limiter filter configured to be destroyed by the laser radiation exceeding the predefined damage threshold, the sacrificial limiter filter including a first layer of graphene disposed on the substrate, a second layer of graphene, and a layer of dielectric material sandwiched between the first and second layers of graphene, the first and the second layers of graphene configured to absorb and scatter at least a portion of electromagnetic radiation incident on the layers of graphene.
2. The optical device of claim 1 , wherein the optical device is a focal plane array (FPA) or a charge coupled device (CCD) camera.
3. The optical device of claim 2 , wherein the optical device is a backside-illuminated FPA or CCD camera.
4. The optical device of claim 1 , wherein at least one of the first and the second layers of graphene further comprises at least one polymer having the graphene contained therein.
5. The optical device of claim 4 , wherein the at least one polymer includes an epoxy oligomer, wherein the epoxy oligomer is at least one of an optical adhesive and an optical photoresist.
6. The optical device of claim 4 , wherein a concentration of graphene in the at least one polymer is in a range of about 0.2% to about 3% by weight.
7. The optical device of claim 4 , wherein at least one of the first and the second layers of graphene further comprises at least one allotrope of carbon.
8. The optical device of claim 1 , wherein optical transmission of at least one of the first and the second layers of graphene is at least 70% in the predefined spectral range.
9. The optical device of claim 1 , wherein the substrate is a silicon substrate integrated into the optical device.
10. The optical device of claim 1 , wherein the optical device further comprises an aperture, and the substrate is a glass substrate positioned proximate the aperture.
11. The optical device of claim 1 , wherein the layer of dielectric material comprises alternating layers of low and high refraction dielectric materials.
12. A backside-illuminated CMOS detector comprising:
a silicon substrate; and
at least one layer of graphene-polymer material disposed on a surface of the silicon substrate, the graphene/polymer material having a thickness in a range of about 50 microns to about 150 microns and including a concentration of graphene in photoresist that is in a range of about 0.2% to about 2% by weight, and an optical transmission of the graphene/polymer material for an infrared operational signal being in a range of about 75% to about 85%.