Transmitting light with lateral variation

• US 8,437,582 B2
• Filed: 03/23/2009
• Issued: 05/07/2013
• Est. Priority Date: 12/22/2005
• Status: Active Grant

• Current Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Original Assignee: Palo Alto Research Center, Inc. (Xerox Holdings Corp.)
• Inventors: Kiesel, Peter, Schmidt, Oliver
• Primary Examiner(s): Le, Uyen Chau N
• Assistant Examiner(s): Prince, Kajli
• Application Number:
  US12/409,003
• Publication Number:
  US 20090220189A1
• Time in Patent Office: 1,506 Days
• Field of Search: 385/12
• US Class Current: 385/12
• CPC Class Codes: G01J 1/42 using electric radiation detectors optical or mechanical part G01J1/04; by comparison with a reference light or electric value G01J1/10
• CPC Class Codes: G01J 3/02 Details
• CPC Class Codes: G01J 3/0208 using focussing or collimating elements, e.g. lenses or mirrors; performing aberration correction
• CPC Class Codes: G01J 3/0216 using light concentrators or collectors or condensers
• CPC Class Codes: G01J 3/0218 using optical fibers
• CPC Class Codes: G01J 3/024 using means for illuminating a slit efficiently (e.g. entrance slit of a spectrometer or entrance face of fiber)
• CPC Class Codes: G01J 3/0256 Compact construction
• CPC Class Codes: G01J 3/26 using multiple reflection, e.g. Fabry-Perot interferometer, variable interference filters
• CPC Class Codes: G01J 3/2803 using photoelectric array detector
• CPC Class Codes: G01J 9/00 Measuring optical phase difference devices or arrangements for controlling the phase of light beams G02F1/01; Determining degree of coherence; Measuring optical wavelength spectrometry G01J3/00
• 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 5/284 of etalon type comprising a resonant cavity other than a thin solid film, e.g. gas, air, solid plates etalons for fibre optic multiplexing G02B6/29358; etalons for spectral measurement G01J3/26
• CPC Class Codes: G02B 6/29317 Light guides of the optical fibre type
• CPC Class Codes: G02B 6/4204 the coupling comprising intermediate optical elements, e.g. lenses, holograms encapsulated active devices H01S5/02208, H01L33/52
• CPC Class Codes: G02B 6/4298 coupling with non-coherent light sources and/or radiation detectors, e.g. lamps, incandescent bulbs, scintillation chambers
• CPC Class Codes: G02F 1/29 for the control of the position or the direction of light beams, i.e. deflection

Abstract

Input light, such as from an optical sensor or stimulus-wavelength converter, includes one or more light or dark sub-bands. The input light is transmitted, such as through a transmissive layer or transmission component, to obtain effects due to transmission with lateral variation. A detector can, for example, obtain spectral information or other photon energy information about the sub-bands due to lateral variation. For each light or dark sub-band, a transmission component can, for example, provide a respective light or dark spot, and spot position can be used to obtain spectral information such as absolute wavelength or wavelength change. A photosensing component can sense or detect transmitted light or output photons, such as with a photosensor array or a position-sensitive detector. Circuitry can use photosensed quantities to obtain, e.g. a differential signal or information about time of wavelength change.

Claims

1. Apparatus comprising:

a transmission structure with entry and exit surfaces, the transmission structure being a layered structure with a laterally varying energy transmission function;

in response to light received at the entry surface that has distributions across a range of photon energies, the transmission structure providing output photons at positions of the exit surface;

a photosensing component that photosenses quantities of photons provided at positions of the exit surface; and

circuitry that responds to the photosensed quantities by providing at least one differential quantity that compares photosensed quantities from the same one of the distributions.

2. The apparatus of claim 1 in which the transmission structure includes at least one of:

a coating on the photosensing component;

a coating on a support structure over the photosensing component;

a wedge-shaped transmission cavity between reflective films;

a staircase-shaped transmission cavity between reflective films;

a laterally graded Bragg mirror with laterally graded layers;

a layer with two-dimensional variation in optical thickness;

a layer with laterally varying thickness; and

a layer with laterally varying refractive index.

3. The apparatus of claim 1 in which the photosensing component includes at least one of:

a photosensor array with CCO readout;

a photosensor array with CMOS readout;

a one-dimensional photosensor array;

a two-dimensional photosensor array;

one or more discrete photosensing devices;

one or more avalanche photodiodes;

one or more photomultiplier tubes; and

a position-sensitive detector.

4. The apparatus of claim 1 in which the circuitry includes at least one of:

a differential amplifier;

circuitry that provides a differential signal; and

circuitry that obtains information about times of wavelength change.