Optical filter array
A device may include a filter array disposed on a substrate. The filter array may include a first mirror disposed on the substrate. The filter array may include a plurality of spacers disposed on the first mirror. A first spacer, of the plurality of spacers, may be associated with a first thickness. A second spacer, of the plurality of spacers, may be associated with a second thickness that is different from the first thickness. A first channel corresponding to the first spacer and a second channel corresponding to the second spacer may be associated with a separation width of less than approximately 10 micrometers (μm). The filter array may include a second mirror disposed on the plurality of spacers.
1. A device, comprising:
a first mirror disposed on a substrate;
a plurality of spacers disposed on the first mirror,
a first spacer, of the plurality of spacers, being associated with a first thickness,
a second spacer, of the plurality of spacers, being associated with a second thickness that is different from the first thickness;
a first sensor element corresponding to the first spacer; and
a second sensor element corresponding to the second spacer,
a separation width between the first sensor element and the second sensor element being less than approximately 10 micrometers (μm); and
a second mirror disposed on the plurality of spacers,
the second mirror including a first slanted side and a second slanted side, and
the second slanted side being on an opposite side of the second mirror from the first slanted side.
2. The device of claim 1 , wherein the second mirror is aligned with the first sensor element, the second sensor element, and a third sensor element.
3. The device of claim 1 , wherein the plurality of spacers are deposited onto the substrate using at least one of:
a physical vapor deposition (PVD) process,
a chemical vapor deposition (CVD) process, or
a lift-off process.
4. The device of claim 1 ,
wherein the first thickness or the second thickness is selected to pass through a particular spectral range of light, and
wherein the particular spectral range of light includes at least one of:
an ultraviolet (UV) spectral range,
a visible spectral range,
a near infrared (NIR) spectral range,
a mid-wavelength infrared (MWIR) spectral range, or
a low-wavelength infrared (LWIR) spectral range.
5. The device of claim 1 , wherein the device is a silicon-based detector or an indium gallium arsenide (InGaAS)-based detector.
6. The device of claim 1 , wherein the device is a hyperspectral imaging sensor with less than a threshold quantity of channels.
7. The device of claim 1 , wherein the first mirror or the second mirror is a metal mirror including a silver layer or an aluminum layer.
8. The device of claim 1 , wherein the first mirror or the second mirror is a quarterwave stack including a low refractive index material and a high refractive index material,
the low refractive index material including at least one of:
a magnesium fluoride (MgF2) layer, or
a silicon oxide (SiO2) layer.
9. The device of claim 1 , wherein the first mirror or the second mirror is a quarterwave stack including a low refractive index material and a high refractive index material,
the high refractive index material including at least one of:
a hydrogenated silicon (Si:H) layer,
a niobium pentoxide (Nb2O5) layer,
a tantalum pentoxide (Ta2O5) layer,
a titanium dioxide (TiO2) layer, or
a hafnium dioxide (HfO2) layer.
10. The device of claim 1 , wherein the plurality of spacers include at least one of:
a hydrogenated silicon (Si:H) layer,
a niobium pentoxide (Nb2O5) layer,
a tantalum pentoxide (Ta2O5) layer,
a titanium dioxide (TiO2) layer, or
a hafnium oxide (HfO2) layer.
11. A device, comprising:
a mirror;
a first spacer disposed on the mirror;
a second spacer disposed on the mirror;
a first sensor element corresponding to the first spacer;
a second sensor element corresponding to the second spacer;
a separation width between the first sensor element and the second sensor element being less than approximately 10 micrometers (μm); and
a different mirror disposed on the first spacer and the second spacer,
the different mirror including a first slanted side and a second slanted side, and
the second slanted side being on an opposite side of the different mirror from the first slanted side.
12. The device of claim 11 , wherein the different mirror is aligned with the first sensor element and the second sensor element.
13. The device of claim 11 , wherein the mirror or the different mirror is a metal mirror including a silver layer or an aluminum layer.
14. The device of claim 11 ,
wherein the mirror or the different mirror is a quarterwave stack including a low refractive index material and a high refractive index material, and
wherein the low refractive index material includes at least one of:
a magnesium fluoride (MgF2) layer, or
a silicon oxide (SiO2) layer.
15. The device of claim 11 ,
wherein the mirror or the different mirror is a quarterwave stack including a low refractive index material and a high refractive index material, and
wherein the high refractive index material includes at least one of:
a hydrogenated silicon (Si:H) layer,
a niobium pentoxide (Nb2O5) layer,
a tantalum pentoxide (Ta2O5) layer,
a titanium dioxide (TiO2) layer, or
a hafnium dioxide (HfO2) layer.
16. The device of claim 11 ,
wherein the first spacer includes a first thickness,
wherein the second spacer includes a second thickness,
wherein the first thickness or the second thickness is selected to pass through a particular spectral range of light, and
wherein the particular spectral range of light includes at least one of:
an ultraviolet (UV) spectral range,
a visible spectral range,
a near infrared (NIR) spectral range,
a mid-wavelength infrared (MWIR) spectral range, or
a low-wavelength infrared (LWIR) spectral range.
17. The device of claim 11 , wherein the device is a silicon-based detector or an indium gallium arsenide (InGaAS)-based detector.
18. The device of claim 11 , further comprising at least one of:
a blocker layer disposed on the mirror; or
a protective layer disposed on the mirror.
19. The device of claim 11 , wherein the first spacer and the second spacer include at least one of:
a hydrogenated silicon (Si:H) layer,
a niobium pentoxide (Nb2O5) layer,
a tantalum pentoxide (Ta2O5) layer,
a titanium dioxide (TiO2) layer, or
a hafnium oxide (HfO2) layer.
20. The device of claim 11 ,
wherein the mirror is disposed on a substrate, and
wherein a set of photodiodes are positioned in the substrate.