Labeling and authenticating using a microtag
An identifier made using a silicon film fragment. The silicon film has a varying optical index of refraction. The varying optical index of refraction reflects one or more spectral peaks when illuminated with light. The one or more spectral peaks includes a reference peak. The silicon film is fragmented to generate the silicon film fragment.
1. An identifier, comprising:
a silicon film fragment;
wherein a silicon film has a varying optical index of refraction;
wherein the varying optical index of refraction reflects one or more spectral peaks when illuminated with light;
wherein the one or more spectral peaks includes a reference peak; and
wherein the silicon film is fragmented to generate the silicon film fragment.
2. The identifier as in claim 1 , wherein the silicon film fragment has an identifying data value associated with the one or more spectral peaks.
3. The identifier as in claim 2 , wherein the identifying data value includes an error correction code data.
4. The identifier as in claim 2 , wherein the identifying data value comprises a digital signature value.
5. The identifier as in claim 2 , wherein the identifying data value includes a channel code data.
6. The identifier as in claim 1 , wherein the silicon film fragment is added to an object for identification.
7. The identifier as in claim 1 , wherein the silicon film fragment comprises a rugate microtag.
8. The identifier as in claim 7 , wherein the varying optical index of refraction is generated using etching.
9. The identifier as in claim 8 , wherein the etching comprises electrochemical etching.
10. The identifier as in claim 9 , wherein the electrochemical etching creates small pores.
11. The identifier as in claim 1 , wherein the varying optical index of refraction comprises a sine-wave refractive index profile.
12. The identifier as in claim 1 , wherein the varying optical index of refraction comprises a plurality of composite sine-wave refractive index profiles.
13. The identifier as in claim 1 , wherein the reference peak position is a highest energy peak.
14. The identifier as in claim 1 , wherein the reference peak position is a lowest energy peak.
15. The identifier as in claim 1 , wherein the silicon film fragment is oxidized.