Sensor using plasmon resonance

• US 20090103095A1
• Filed: 10/18/2007
• Published: 04/23/2009
• Est. Priority Date: 10/18/2007
• Status: Active Grant

• Current Assignee: Hewlett Packard Enterprise Development LP (Hewlett-Packard Enterprise Company)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Fiorentino, Marco, Fattal, David A., Wu, Wei, Beausoleil, Raymond G.
• Granted Patent: US 8,673,217 B2
• Time in Patent Office: Days
• US Class Current: 356/406
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: G01J 3/51 using colour filters
• CPC Class Codes: G01J 3/513 having fixed filter-detector pairs
• CPC Class Codes: G01N 2021/258 Surface plasmon spectroscopy, e.g. micro- or nanoparticles in suspension
• CPC Class Codes: G01N 21/251 Colorimeters; Construction thereof
• CPC Class Codes: G02B 5/008 Surface plasmon devices diffractive gratings with a pitch less than or comparable to the wavelength G02B5/1809; surface plasmons in integrated optics G02B6/1226; optical analysis of materials by means of surface plasmons G01N21/553
• CPC Class Codes: G02B 5/201 in the form of arrays

Abstract

A sensing system can include one or more particles having one or more plasmon resonances. The particles can be positioned adjacent to the active region of a sensor to enhance the sensitivity of the sensor to electromagnetic radiation having frequencies corresponding to the plasmon resonances. An array of sensors such as used for color imaging can employ different types of particles adjacent to different sensors, so that different sensors sense different colors. During fabrication of such sensors, the particles can be applied mechanically or using a process such as inkjet printing.

Claims

1. A sensing system comprising:

a sensor having a photoactive region; and

a particle having a plasmon resonance, the particle being positioned in the sensor to enhance sensitivity of the photoactive region to electromagnetic radiation having a frequency corresponding to the plasmon resonance.

2. The system of claim 1, wherein the sensor comprises a photodiode containing the photoactive region.

3. The system of claim 1, further comprising a plurality of particles having the plasmon resonance, wherein the particles are adjacent to the photoactive region.

4. The system of claim 3, further comprising a binding material attached to the sensor and the particles.

5. The sensing system of claim 1, wherein the particle is spherical and has a diameter less than about 50 nm.

6. The sensing system of claim 1, wherein the particles are embedded in the active region.

7. An image sensor comprising:

an array of sensors including a first group of the sensors and a second group of the sensors;

a plurality of first particles, wherein the first particles are positioned to create a first plasmon resonance in the first group of the sensors and thereby enhance sensitivity of the sensors in the first group to electromagnetic radiation having a first frequency that corresponds to the first plasmon resonance; and

a plurality of second particles, wherein the second particles are positioned to create a second plasmon resonance in the second group of the sensors and thereby enhance sensitivity of the sensors in the second group to electromagnetic radiation having a second frequency that corresponds to the second plasmon resonance.

8. The image sensor of claim 7, further comprising a plurality of third particles, wherein the array of sensors further includes a third group of the sensors, and the third particles are positioned to create a third plasmon resonance in the third group of the sensors and thereby enhance sensitivity of the sensors in the third group to electromagnetic radiation having a third frequency that corresponds to the third plasmon resonance.

9. The image sensor of claim 8, wherein the first frequency, the second frequency, and the third frequency respectively correspond to red light, green light, and blue light.

10. The image sensor of claim 7, wherein the array of sensors is selected from a group consisting of a CCD sensor array and a CMOS sensor array.

11. The image sensor of claim 7, wherein the first particles differ in size from the second particles.

12. The image sensor of claim 7, wherein the first and second particles are spherical, and the first particles have a first diameter that differs from a second diameter of the second particles.

13. A process comprising:

fabricating an array of sensors having photoactive regions;

applying first particles adjacent to the photoactive regions of a first group of the sensors in the array, the first particles creating first plasmon resonances that enhance sensitivity of the sensors in the first group to electromagnetic radiation having a first frequency that corresponds to the first plasmon resonance; and

applying second particles adjacent to the photoactive regions of a second group of the sensors in the array, the second particles creating second plasmon resonances that enhance sensitivity of the sensors in the second group to electromagnetic radiation having a second frequency that corresponds to the second plasmon resonance.

14. The process of claim 13, further comprising applying third particles adjacent to the photoactive regions of a third group of the sensors in the array, the third particles creating third plasmon resonances that enhance sensitivity of the sensors in the third group to electromagnetic radiation having a third frequency that corresponds to the third plasmon resonance.

15. The process of claim 14, wherein the first frequency, the second frequency, and the third frequency respectively correspond to red light, green light, and blue light.

16. The process of claim 13, wherein applying the first and second particles comprises printing onto the array using first and second inks that respectively containing the first and second particles.

17. The process of claim 16, wherein the printing uses an inkjet process.

18. The process of claim 13, wherein applying the first and second particles comprises:

applying an adhesive to a surface of the array; and

mechanically placing the first and second particles into the adhesive on the array.

19. The process of claim 13, wherein applying the first particles comprises:

depositing a layer on the array, the layer contain the first particles mixed in a first material; and

using photolithography to pattern the layer into regions that overlie the photoactive regions of the first group of the sensors.