Optical reader for diffraction grating-based encoded optical identification elements
An optical reader system 7 for diffraction grating-based encoded microbeads (or bead reader system), comprises a reader box 100, which accepts a bead cell (or cuvette) 102 that holds the microbeads 8, having an embedded code therein. The reader box 100 interfaces along lines 103 with a known computer system 104. The reader box 100 interfaces with a stage position controller 112 and the controller 112 interfaces along a line 115 with the computer system 104 and a manual control device (or joy stick) 116 along a line 117. The reader interrogates the microbeads to determine the embedded code and/or the fluorescence level on the beads. The reader provides information similar to a bead flow cytometer but in a planar format, i.e., a virtual cytometer.
1. An optical reader comprising:
said reader capable of receiving at least one encoded substrate having at least one diffraction grating disposed therein, said grating having a resultant refractive variation at a grating location;
said grating providing an output optical signal indicative of a code when illuminated by an incident input light signal propagating in free space;
a source light providing said input light signal incident at a location where said substrates are located when loaded, wherein said source light includes an optical code signal and an optical fluorescence excitation signal; and
a reader which reads said output optical signal and provides a code signal indicative of said code.
2. The apparatus of claim 1 wherein said output optical signal comprises a fluorescent optical signal from said substrate and said reader reads said output optical signal and provides a signal indicative of said fluorescent optical signal.
3. The apparatus of claim 1 wherein said optical fluorescence excitation signal comprises light having a wavelength of about 633 nm.
4. The apparatus of claim 1 wherein said optical fluorescence excitation signal comprises light having a wavelength of about 532 nm.
5. The apparatus of claim 1 wherein said substrate is made of a glass material.
6. The apparatus of claim 1 wherein said code comprises a plurality of bits.
7. The apparatus of claim 1 wherein said grating includes a number of pitches indicative of a number of bits in said code.
8. The apparatus of claim 1 wherein said substrate has a length that is less than about 500 microns.
9. The apparatus of claim 1 wherein said substrate has a cylindrical shape.
10. The apparatus of claim 1 wherein said substrate is a particle or bead.
11. The apparatus of claim 1 wherein said source light includes a first laser having said optical code signal and a second laser having said fluorescent optical signal.
12. The apparatus of claim 11 wherein said first laser has a first beam shape and said second laser has a second beam shape, said first and second beam shapes being different.
13. The apparatus of claim 11 wherein said first laser has a first beam path and said second laser has a second beam path, said first and second beam paths overlapping for at least a portion of the beam paths.
14. The apparatus of claim 1 wherein said source light includes a first laser forming a first beam and a second laser forming a second beam, wherein the apparatus further comprises a combiner for combining the first and second beams.
15. A method of reading a code in an encoded substrate, comprising:
obtaining a substrate at least a portion of which having at least one diffraction grating disposed therein, said grating having a resultant refractive variation at a grating location;
said grating providing an output optical signal indicative of a code when illuminated by an incident light signal propagating in free space;
illuminating said substrate with said incident light signal, said substrate providing an output light signal, said incident light signal including an optical code signal and an optical fluorescence excitation signal; and
reading said output light signal and detecting a code and fluorescence therefrom.
16. The method of claim 15 wherein said substrate is a particle or bead.
17. The method of claim 15 wherein said illuminating said substrate includes using a first laser including said optical code signal and a second laser including said fluorescent optical signal.
18. The method of claim 17 wherein said first laser has a first beam shape and said second laser has a second beam shape, said first and second beam shapes being different.
19. The method of claim 17 wherein said first laser has a first beam path and said second laser has a second beam path, said first and second beam paths overlapping for at least a portion of the beam paths.
20. The method of claim 17 further comprising combining light from said first laser and said second laser into a combined laser beam.
21. The method of claim 15 wherein said substrate has a length that is less than about 500 microns.
22. The method of claim 15 wherein said substrate has a cylindrical shape.