Metal mirror based multispectral filter array
A device may include a multispectral filter array disposed on the substrate. The multi spectral filter array may include a first metal mirror disposed on the substrate. The multi spectral filter may include a spacer disposed on the first metal mirror. The spacer may include a set of layers. The spacer may include a second metal mirror disposed on the spacer. The second metal mirror may be aligned with two or more sensor elements of a set of sensor elements.
1. A device, comprising:
a multispectral filter array disposed on a substrate,
the multispectral filter array including:
a first metal mirror disposed on the substrate,
a spacer disposed on the first metal mirror,
the spacer including a set of layers,
a second metal mirror disposed on the spacer; and
wherein the second metal mirror is aligned with two or more sensor elements of a set of sensor elements.
2. The device of claim 1 , where the first metal mirror has a uniform thickness over the set of sensor elements.
3. The device of claim 1 , where the second metal mirror is aligned with all of the set of sensor elements.
4. The device of claim 1 , where the set of layers comprises:
a set of spacer layers,
a first layer of the set of spacer layers corresponding to a first channel, of a set of optical channels aligned to the set of sensor elements, and being associated with a first thickness, and
a second layer of the set of spacer layers corresponding to a second channel, of the set of optical channels, and being associated with a second thickness that is different than the first thickness,
the first layer covering a first quantity of sensor elements of the set of sensor elements,
the second layer covering a second quantity of sensor elements of the set of sensor elements,
the second quantity being half the first quantity.
5. The device of claim 1 , where the first metal mirror and the second metal mirror include at least one of:
a silver (Ag)-based mirror,
an aluminum (Al)-based mirror, or
a copper (Cu)-based mirror.
6. The device of claim 1 , where the spacer includes at least one of:
an amorphous silicon-based material,
a hydrogenated amorphous silicon (Si:H)-based material,
a germanium (Ge)-based material,
a niobium-oxide (Nb 2 O 5 )-based material,
a titanium-oxide (TiO 2 )-based material,
a tantalum-oxide (Ta 2 O 5 )-based material,
a silicon-oxide (SiO 2 )-based material,
an yttrium-oxide (Y 2 O 3 )-based material,
a zirconium-oxide (ZrO 2 )-based material,
an aluminum-oxide (Al 2 O 3 )-based material,
a silicon-nitride (Si 3 N 4 )-based material.
7. The device of claim 1 , where one or more layers of the multispectral filter array are deposited layers, the deposited layers being deposited on the substrate using a pulsed magnetron sputtering process.
8. The device of claim 1 , where the set of sensor elements further comprise at least one of:
a photodiode array,
a charge-coupled device (CCD), or
a complementary metal-oxide-semiconductor (CMOS).
9. The device of claim 1 , where the multispectral filter array further includes:
a first set of zinc (Zn) oxide protective layers sandwiching the first metal mirror; and
a second set of zinc (Zn) oxide protective layers sandwiching the second metal mirror.
10. The device of claim 1 , further comprising:
one or more filter layers disposed on the multispectral filter array to filter light directed to the set of sensor elements,
the one or more filter layers including at least one of:
an out-of-band blocking set of layers,
an anti-reflective coating set of layers, or
a higher order suppression set of layers.
11. The device of claim 1 , further comprising:
a set of lenses disposed on the multispectral filter array,
a particular lens, of the set of lenses, being associated with directing light toward a particular optical sensor, of the set of sensor elements, via a channel of the multispectral filter array.
12. An optical filter, comprising:
a first layer,
the first layer being a first mirror to reflect a portion of light directed toward the first layer,
the first layer being deposited on a substrate associated with a set of sensor elements;
a second set of layers,
the second set of layers being deposited solely on the first layer,
the second set of layers being associated with a set of channels corresponding to the set of sensor elements,
a channel, of the set of channels, being associated with a particular thickness corresponding to a particular wavelength of light that is to be directed toward a particular sensor element of the set of sensor elements; and
a third layer,
the third layer being a second metal mirror to reflect a portion of light directed toward the third layer,
the third layer being deposited on a plurality of the set of sensor elements associated with the second set of layers.
13. The optical filter of claim 12 , where a spectral range of light that is directed toward the set of sensor elements when the optical filter is exposed to a light source is between approximately 380 nanometers and approximately 1100 nanometers.
14. The optical filter of claim 12 , where the first layer having been deposited on the substrate via a pulsed magnetron sputtering process.
15. The optical filter of claim 12 , where at least one of the first layer or the third layer includes a first oxide-based protective layer, a metal-based reflector layer, and a second oxide-based protective layer,
the metal-based reflector layer being sandwiched between the first oxide-based protective layer and the second oxide-based protective layer.
16. The device of claim 1 , where the set of sensor elements are embedded into the substrate.
17. The device of claim 1 , where the set of sensor elements are a plurality of optical sensors of a sensor array.
18. The device of claim 1 , where the set of sensor elements are associated with receiving a portion of light from a light source.
19. The device of claim 1 , where the set of sensor elements is a back illuminated sensor array.
20. The device of claim 1 , where the set of layers comprise a material selected to reduce an angle shift of light directed from a light source toward the set of sensor elements.