TYPE SELECTIVE AND POLARIZATION SELECTIVE DEVICE FOR RAMAN SPECTROSCOPY

• US 20100321685A1
• Filed: 06/19/2009
• Published: 12/23/2010
• Est. Priority Date: 06/19/2009
• Status: Active Grant

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Li, Jingjing, Li, Zhiyong, Wu, Wei
• Granted Patent: US 7,907,275 B2
• Time in Patent Office: Days
• US Class Current: 356/301
• CPC Class Codes: G01J 3/02 Details
• CPC Class Codes: G01J 3/0224 using polarising or depolarising elements
• CPC Class Codes: G01J 3/44 Raman spectrometry; Scattering spectrometry ; Fluorescence spectrometry
• CPC Class Codes: G01N 21/658 enhancement Raman, e.g. surface plasmons

Abstract

A type and polarization selective device for Raman spectroscopy includes a set of at least two antennas and a gap at their intersection. First antenna geometry is such that it is configured to resonate, for first or second (different from the first) polarization, at a predetermined stimulation frequency of a material for which Raman scattering is to be studied, or at a Stokes or anti-Stokes frequency corresponding with the material when excited at stimulation frequency. Second antenna geometry is such that it is configured to resonate, for the other of second or first polarization, at the Stokes frequency when the first antenna is configured to resonate at the stimulation or anti-Stokes frequency, or at the anti-Stokes frequency when the first antenna is configured to resonate at the stimulation or Stokes frequency, or at the stimulation frequency when the first antenna is configured to resonate at the Stokes or anti-Stokes frequency.

Claims

1. A type selective and polarization selective device for Raman spectroscopy, the device comprising:

a set of at least two antennas, including;

a first antenna having a first geometry such that the first antenna is configured to resonate, for one of a first polarization or a second polarization that is different from the first polarization, at one of a predetermined stimulation frequency of a material for which Raman scattering is to be studied, a Stokes frequency corresponding with the material when excited at the predetermined stimulation frequency, or an anti-Stokes frequency corresponding with the material when excited at the predetermined stimulation frequency; and

a second antenna intersecting the first antenna, the second antenna having a second geometry such that the second antenna is configured to resonate, for an other of the second polarization or the first polarization, at the Stokes frequency when the first antenna is configured to resonate at the predetermined stimulation frequency or at the anti-Stokes frequency, or at the anti-Stokes frequency when the first antenna is configured to resonate at the predetermined stimulation frequency or at the Stokes frequency, or at the predetermined stimulation frequency when the first antenna is configured to resonate at the Stokes frequency or at the anti-Stokes frequency; and

a gap located at an intersection of the at least two antennas, the gap configured to have the material established therein.

2. The device as defined in claim 1 wherein the first antenna geometry is different from the second antenna geometry.

3. The device as defined in claim 1, further comprising a third antenna intersecting both the first and second antennas, the third antenna having a third geometry such that the third antenna is configured to resonate, for a polarization other than the first polarization or the second polarization, at the Stokes frequency when the first antenna is configured to resonate at the predetermined stimulation frequency or at the anti-Stokes frequency, or at the anti-Stokes frequency when the first antenna is configured to resonate at the predetermined stimulation frequency or at the Stokes frequency, or at the predetermined stimulation frequency when the first antenna is configured to resonate at the Stokes frequency or at the anti-Stokes frequency.

4. The device as defined in claim 1, further comprising the material established in the gap, wherein the material is selected from chemical species, biological species, and combinations thereof.

5. The device as defined in claim 4 wherein the material established in the gap is silicon, wherein the antenna set is established on a silicon dioxide substrate, and wherein a length of each segment of the first antenna is 140 nm and the first antenna is configured to resonate at a stimulation frequency of silicon for X polarization, and wherein a length of each segment of the second antenna is 110 nm and the second antenna is configured to resonate at an anti-Stokes frequency of silicon for Y polarization.

6. The device as defined in claim 4 wherein the material established in the gap is silicon, wherein the antenna set is established on a silicon dioxide substrate, and wherein a length of each segment of the first antenna is 164 nm and the first antenna is configured to resonate at a Stokes frequency of silicon for Y polarization, and wherein a length of each segment of the second antenna is 115 nm and the second antenna is configured to resonate at an anti-Stokes frequency of silicon for X polarization.

7. The device as defined in claim 1 wherein the first antenna is configured to enhance a local field at the predetermined stimulation frequency which in turn enhances an excitation process of the Raman scattering, and wherein a radiation process at the Stokes frequency is enhanced by the second antenna that is configured to resonate at the Stokes frequency.

8. The device as defined in claim 1 wherein the first antenna is configured to enhance a local field at the predetermined stimulation frequency which in turn enhances an excitation process of the Raman scattering, and wherein a radiation process at the anti-Stokes frequency is enhanced by the second antenna that is configured to resonate at the anti-Stokes frequency.

9. The device as defined in claim 1 wherein each of the first and second antennas is linear.

10. The device as defined in claim 1, further comprising:

a substrate upon which the set is established; and

at least one other set of at least two other antennas established on the substrate, the at least one other set including;

an other first antenna having an other first geometry such that the other first antenna is configured to resonate, for one of a first polarization or a second polarization that is different from the first polarization, at one of the predetermined stimulation frequency of the material, a Stokes frequency corresponding with a peak of the material when excited at the predetermined stimulation frequency, or an anti-Stokes frequency corresponding with a peak of the material when excited at the predetermined stimulation frequency, wherein when the other first antenna is configured to resonate at the Stokes or anti-Stokes frequency for the peak of the material, the peak is different from a peak of the material at which the first antenna of the set is configured to resonate; and

an other second antenna intersecting the other first antenna, the other second antenna having an other second geometry such that the other second antenna is configured to resonate, for an other of the second polarization or the first polarization, at the Stokes frequency when the other first antenna is configured to resonate at the predetermined stimulation frequency or at the anti-Stokes frequency, or at the anti-Stokes frequency when the other first antenna is configured to resonate at the predetermined stimulation frequency or at the Stokes frequency, or at the predetermined stimulation frequency when the other first antenna is configured to resonate at the Stokes frequency or at the anti-Stokes frequency, wherein when the other second antenna is configured to resonate at the Stokes or anti-Stokes frequency for the peak of the material, the peak is different from a peak of the material at which the second antenna of the set is configured to resonate; and

a gap located at an intersection of the at least two other antennas, the gap configured to have the material established therein.

11. A type selective and polarization selective system for Raman spectroscopy, comprising:

a light source; and

a Raman scattering device configured to have light from the light source incident thereon, the Raman scattering device including;

a set of at least two antennas, including;

a first antenna having a first geometry such that the first antenna is configured to resonate, for one of a first polarization or a second polarization that is different from the first polarization, at one of a predetermined stimulation frequency of a material for which Raman scattering is to be studied, a Stokes frequency corresponding with the material when excited at the predetermined stimulation frequency, or an anti-Stokes frequency corresponding with the material when excited at the predetermined stimulation frequency; and

a second antenna intersecting the first antenna, the second antenna having a second geometry such that the second antenna is configured to resonate, for an other of the second polarization or the first polarization, at the Stokes frequency when the first antenna is configured to resonate at the predetermined stimulation frequency or at the anti-Stokes frequency, or at the anti-Stokes frequency when the first antenna is configured to resonate at the predetermined stimulation frequency or at the Stokes frequency, or at the predetermined stimulation frequency when the first antenna is configured to resonate at the Stokes frequency or at the anti-Stokes frequency; and

a gap located at an intersection of the first and second antennas, the gap configured to have the material established therein.

12. The system as defined in claim 11 wherein the light source is configured to emit the predetermined stimulation frequency, and wherein the system further comprises a detector configured to detect at least one of the Stokes frequency or the anti-Stokes frequency.

13. A method for making a type selective and polarization selective device for Raman spectroscopy, the method comprising:

selecting a geometry for a first of at least two antennas such that the first antenna resonates, for a first polarization, at one of a predetermined stimulation frequency of a material for which Raman scattering is to be studied, a Stokes frequency corresponding with the material when excited at the predetermined stimulation frequency, or an anti-Stokes frequency corresponding with the material when excited at the predetermined stimulation frequency;

selecting a geometry for a second of the at least two antennas such that the second antenna resonates, for a second polarization that is different from the first polarization, at the Stokes frequency when the first antenna is configured to resonate at the predetermined stimulation frequency or at the anti-Stokes frequency, or at the anti-Stokes frequency when the first antenna is configured to resonate at the predetermined stimulation frequency or at the Stokes frequency, or at the predetermined stimulation frequency when the first antenna is configured to resonate at the Stokes frequency or at the anti-Stokes frequency; and

establishing the at least two antennas such that the first and second antennas intersect at a shared gap, the shared gap configured to have the material established therein.

14. The method as defined in claim 13 wherein establishing the at least two antennas includes positioning the first antenna 90°

with respect to the second antenna such that the first and second antennas exhibit perpendicular polarizations.

15. The method as defined in claim 13, further comprising enhancing Stokes scattering by:

selecting a length for each segment of the first antenna such that the first antenna enhances a local field at the predetermined stimulation frequency, thereby enhancing an excitation process of the Raman scattering; and

selecting a length for each segment of the second antenna such that the second antenna resonates at the Stokes frequency, thereby enhancing a radiation process at the Stokes frequency.

16. The method as defined in claim 13, further comprising enhancing anti-Stokes scattering by:

selecting a length for each segment of the first antenna such that the first antenna enhances a local field at the predetermined stimulation frequency, thereby enhancing an excitation process of the Raman scattering; and

selecting a length for each segment of the second antenna such that the second antenna resonates at the anti-Stokes frequency, thereby enhancing a radiation process at the anti-Stokes frequency.

17. The method as defined in claim 13, further comprising enhancing both Stokes and anti-Stokes scattering by:

selecting a length for each segment of the first antenna such that the first antenna resonates at the Stokes frequency, thereby enhancing a radiation process at the Stokes frequency; and

selecting a length for each segment of the second antenna such that the second antenna resonates at the anti-Stokes frequency, thereby enhancing a radiation process at the anti-Stokes frequency.

18. The method as defined in claim 13 wherein establishing the first and second antennas is accomplished by i) at least one of nanoimprint lithography, electron-beam lithography, photo-lithography, extreme ultraviolet (EUV) lithography, or X-ray lithography;

or ii) deposition and etching of a metal material;

or iii) deposition of a metal material and lift-off to pattern the metal material.

19. The method as defined in claim 13, further comprising:

selecting a geometry for a third of the at least two antennas such that the third antenna is configured to resonate, for a third polarization other than the first polarization or the second polarization, at the Stokes frequency when the first antenna is configured to resonate at the predetermined stimulation frequency or at the anti-Stokes frequency, or at the anti-Stokes frequency when the first antenna is configured to resonate at the predetermined stimulation frequency or at the Stokes frequency, or at the predetermined stimulation frequency when the first antenna is configured to resonate at the Stokes frequency or at the anti-Stokes frequency; and

establishing the third antenna such that the first, second and third antennas intersect at the shared gap.

20. The method as defined in claim 13 wherein prior to selecting the geometries of the first and second antennas, the method further comprises:

selecting a size of the gap;

selecting the material to be established in the gap; and

selecting the geometries of the first and second antennas to correspond with the selected gap size and material, thereby controlling the resonances of each of the first and second antennas.