ANALYZING LIGHT BY MODE INTERFERENCE

• US 20140362374A1
• Filed: 04/25/2012
• Published: 12/11/2014
• Est. Priority Date: 04/25/2012
• Status: Active Grant

• Current Assignee: Valtrus Innovations Limited (f/k/a Dolya Holdco 9 Limited) (Key Patent Innovations Limited)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Santori, Charles M., Fiorentino, Marco, Fattal, David A., Peng, Zhen, Beausoleil, Raymond G., Liang, Di, Faraon, Andrei
• Granted Patent: US 9,176,279 B2
• Time in Patent Office: Days
• US Class Current: 356/301
• CPC Class Codes: G01J 3/0227 using notch filters
• CPC Class Codes: G01J 3/0259 Monolithic
• CPC Class Codes: G01J 3/1895 using fiber Bragg gratings or gratings integrated in a waveguide
• CPC Class Codes: G01J 3/2823 Imaging spectrometer
• CPC Class Codes: G01J 3/4412 Scattering spectrometry particle sizing by light scattering G01N15/0205; optical velocimetry of particles G01P5/20, G01P5/26
• CPC Class Codes: G01J 3/45 Interferometric spectrometry
• CPC Class Codes: G02B 2006/12152 Mode converter
• CPC Class Codes: G02B 6/2813 based on multimode interference effect, i.e. self-imaging
• CPC Class Codes: G02F 1/217 Multimode interference type

Abstract

Apparatuses and systems for analyzing light by mode interference are provided. An example of an apparatus for analyzing light by mode interference includes a number of waveguides to support in a multimode region two modes of the light of a particular polarization and a plurality of scattering objects offset from a center of at least one of the number of waveguides.

Claims

1. An apparatus for analyzing light by mode interference, comprising:

a number of waveguides to support in a multimode region two modes of the light of a particular polarization; and

a plurality of scattering objects offset from a center of at least one of the number of waveguides.

2. The apparatus of claim 1, comprising a single-mode input waveguide to collect a single mode of the light emitted from a single source and input the single mode of light into the number of waveguides that separate the single mode in the multimode region into the two modes of the light.

3. The apparatus of claim 1, wherein the number of waveguides comprises one multimode waveguide to support the two modes of the light in the multimode region.

4. The apparatus of claim 1, wherein the number of waveguides comprises two single-mode waveguides to support the two modes of the light in the multimode region.

5. The apparatus of claim 4, wherein a single-mode input waveguide inputs the light into one of the two single-mode waveguides.

6. The apparatus of claim 4, wherein a single-mode input waveguide inputs the light into both of the two single-mode waveguides.

7. The apparatus of claim 1, comprising a charge coupled device with sensors co-aligned with the plurality of scattering objects to collect signals emitted by the plurality of scattering objects.

8. An apparatus for analyzing light by mode interference, comprising:

a number of waveguides to support two modes of the light that have a particular polarization;

a plurality of scattering objects offset from and substantially parallel to a center axis of each of the number of waveguides, wherein the plurality of scattering objects emit signals collected from interference between the two modes of the light that are aliased to a lower frequency.

9. The apparatus of claim 8, comprising non-transitory computer readable instructions executed by a processor to determine a spectrum of the light with Fourier analysis by analysis of an interference pattern determined from the signals emitted by the plurality of scattering objects.

10. The apparatus of claim 8, comprising two modes of two waveguides horizontally displaced that are evanescently coupled to a plurality of scattering objects positioned therebetween.

11. The apparatus of claim 8, comprising two waveguides vertically displaced that are resonantly coupled and the plurality of scattering objects offset substantially vertically from a center of one waveguide, further comprising the signals emitted by the plurality of scattering objects directed substantially away from the other waveguide.

12. The apparatus of claim 11, comprising the signals emitted by each of the plurality of scattering objects directed toward individual p-i-n detectors.

13. A system for analyzing light by mode interference, comprising:

a plurality of scattering objects offset from and substantially parallel to a center axis of each of a number of waveguides, wherein the number of waveguides is formed to support two modes of the light and wherein interference between the two modes of the light is aliased to a lower frequency by emission of signals collected by the plurality of scattering objects; and

a charge coupled device with sensors co-aligned with the plurality of scattering objects to directly collect the signals emitted by the plurality of scattering objects.

14. The system of claim 13, comprising a plurality of substantially parallel waveguides that form a two dimensional array.

15. The system of claim 13, comprising a coarse frequency sorting element for separation of input light into a plurality of different output ranges of optical frequencies.