OPTICALLY ABSORPTIVE MEDIA
The attenuation and other optical properties of a medium are exploited to measure a thickness of the medium between a sensor and a target surface. Disclosed herein are various mediums, arrangements of hardware, and processing techniques that can be used to capture these thickness measurements and obtain three-dimensional images of the target surface in a variety of imaging contexts. This includes general techniques for imaging interior/concave surfaces as well as exterior/convex surfaces, as well as specific adaptations of these techniques to imaging ear canals, human dentition, and so forth.
1 . A composition comprising:
a carrier formed of a transparent fluid medium; and
a plurality of gold nanoparticles uniformly distributed within the carrier, the plurality of gold nanoparticles tuned to absorb optical energy within a predetermined band of visible light wavelengths.
2 . The composition of claim 1 wherein the plurality of gold nanoparticles are tuned using a shape of the plurality of gold nanoparticles.
3 . The composition of claim 1 wherein the plurality of gold nanoparticles are tuned using a size of the plurality of gold nanoparticles.
4 . The composition of claim 1 wherein the plurality of gold nanoparticles has a concentration within the carrier such that the composition has zero attenuation outside the predetermined band.
5 . The composition of claim 1 wherein the predetermined band is between 450 nanometers and 550 nanometers.
6 . The composition of claim 1 wherein the carrier is one or more of an oil, a gel, a gas, and a liquid.
7 . The composition of claim 1 wherein the carrier includes a silicon oil.
8 . The composition of claim 1 wherein the carrier includes a glycerol.
9 . The composition of claim 1 wherein the carrier is curable.
10 . The composition of claim 1 wherein the carrier is biocompatible.
11 . A composition comprising:
a carrier formed of a transparent fluid medium; and
a dye uniformly distributed within the carrier, the dye consisting of a single fluorescent dye having an absorption spectrum over which the dye absorbs light and an emission spectrum at which the dye fluoresces, the absorption spectrum and the emission spectrum having at least one overlapping non-zero region.
12 . The composition of claim 11 wherein the carrier is one or more of an oil, a gel, a gas, and a liquid.
13 . The composition of claim 11 wherein the carrier includes a silicon oil.
14 . The composition of claim 11 wherein the carrier includes a glycerol.
15 . The composition of claim 11 wherein the dye is fluorescein sodium.
16 . The composition of claim 11 wherein the carrier is curable.
17 . The composition of claim 11 wherein the carrier is biocompatible.
18 . The composition of claim 11 wherein the dye is encapsulated in silica nanoparticles.
19 . The composition of claim 11 wherein the absorption spectrum has a peak within a visible light range.
20 . The composition of claim 11 wherein the emission spectrum has a peak within a visible light range.