WO2008080071A1

WO2008080071A1 - Method and apparatus to facilitate multiplexing light in a shared optical conduit

Info

Publication number: WO2008080071A1
Application number: PCT/US2007/088577
Authority: WO
Inventors: Ovidiu Gabriel Vlad; Jr. Lawrence Carl Spaete; Alfred Robert Zantow
Original assignee: Embedded Control Systems
Priority date: 2006-12-21
Filing date: 2007-12-21
Publication date: 2008-07-03
Also published as: WO2008080077A1

Abstract

One provides a source of optical power (101, 202), a source of optical lighting (102, 204), and a source of optically-encoded data (103, 206, 208). The outputs of these various sources are then multiplexed (104) together such that the optical power, the optical lighting, and the optically-encoded data all share a common optical conduit (210). By one approach, this multiplexing can comprise frequency division multiplexing. By this approach, for example, the optical lighting occupies one range of frequencies, the optical power occupies another, different range of frequencies, and the optically-encoded data occupies yet another, different range of frequencies.

Description

METHOD AND APPARATUS TO FACILITATE MULTIPLEXING LIGHT IN A

SHARED OPTICAL CONDUIT

Related Application^)

[0001] This application claims the benefit of U.S. Provisional application number

60/871,349, filed December 21, 2006, which is incorporated by reference in its entirety herein.

[0002] This application is related to co-pending and co-owned U.S. patent application number, entitled METHOD AND APPARATUS TO FACILITATE TRANSMITTING DATA USING MULTIPLE OPTICAL DATA STREAMS attorney's docket number 8462/91303) and filed on even date herewith, which is incorporated by reference in its entirety herein.

Technical Field

[0003] This invention relates generally to light and more particularly to the conveyance of light beams.

Background

[0004] Light serves a variety of purposes. These can include serving as a source of power, as a carrier of data, and of course as a means of visibly illuminating a given surface or area. Numerous sources of light are known to facilitate these various uses of light. In some cases, so-called free space conveyance of light will serve to effect such purposes. In other cases, a bounded optical conduit (such as a light pipe, an optical fiber, or the like) serves to convey the light. For example, it is known to use optical fiber to carry light that has been modulated with data from one location to another.

[0005] It has been proposed that light serve all of these purposes in a given dedicated application setting (such as in a vehicle, a building, or the like). In such a case, the amount of optical fiber utilized to convey such light can be considerable. For example, one fiber (or set of fibers) is used to convey lighting for power applications from an optical power source to one or more corresponding destinations while another fiber (or set of fibers) will serve in a similar manner in a data-conveying network. [0006] Such an approach leads to increased costs, increasingly complex designs, and considerable challenges with respect to installation, trouble shooting, and maintenance. As one simple example in this regard, fibers, in a bundle of fibers, will typically all look alike. This belies, however, the nature and content of the light being conveyed by these different fibers and can render installation and maintenance both difficult and error prone.

Brief Description of the Drawings

[0007] The above needs are at least partially met through provision of the method and apparatus to facilitate multiplexing light in a shared optical conduit described in the following detailed description, particularly when studied in conjunction with the drawings, wherein:

[0008] FIG. 1 comprises a flow diagram as configured in accordance with various embodiments of the invention;

[0009] FIG. 2 comprises a block diagram as configured in accordance with various embodiments of the invention; and

[0010] FIG. 3 comprises a block diagram as configured in accordance with various embodiments of the invention.

[0011] Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions and/or relative positioning of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of various embodiments of the present invention. Also, common but well-understood elements that are useful or necessary in a commercially feasible embodiment are often not depicted in order to facilitate a less obstructed view of these various embodiments of the present invention. It will further be appreciated that certain actions and/or steps may be described or depicted in a particular order of occurrence while those skilled in the art will understand that such specificity with respect to sequence is not actually required. It will also be understood that the terms and expressions used herein have the ordinary technical meaning as is accorded to such terms and expressions by persons skilled in the technical field as set forth above except where different specific meanings have otherwise been set forth herein. Detailed Description

[0012] Generally speaking, pursuant to these various embodiments, one provides a source of optical power, a source of optical lighting, and a source of optically-encoded data.

The outputs of these various sources are then multiplexed together such that the optical power, the optical lighting, and the optically-encoded data all share a common optical conduit.

[0013] By one approach, this multiplexing can comprise frequency division multiplexing. By this approach, for example, the optical lighting occupies one range of frequencies, the optical power occupies another, different range of frequencies, and the optically-encoded data occupies yet another, different range of frequencies.

[0014] So configured, light beams for a variety of dramatically different application purposes all share a same optical conduit. This can result in a significant reduction in required fibers for a given application setting. This can also greatly ease design constraints and simplify installation and maintenance as each fiber carries essentially identical content. Those skilled in the art will recognize and appreciate that these teachings greatly leverage existing approaches in these regards and are also easily scaled to accommodate a wide variety of application settings.

[0015] These and other benefits may become clearer upon making a thorough review and study of the following detailed description. Referring now to the drawings, and in particular to FIG. 1, an illustrative process 100 that is compatible with many of these teachings will now be presented.

[0016] Pursuant to this process 100, one provides 101 a source of optical power. By one approach, this can comprise providing a source of infrared light though light of other wavelengths is possible. In general, the particular wavelength employed will correspond to the light-to-electricity conversion technology being used in a given application setting. Various options in this regard are well known to those skilled in the art and will not be repeated here.

[0017] This process 100 also makes provision for providing 102 a source of optical lighting. As used herein, the expression "lighting" will be understood to refer to light in the visible spectrum (that is, light that is naturally visible to the average and ordinary human being without the aid of special tools or perception enhancing equipment). This can include both so-called full spectrum visible light as well as visible light having less than all possible color components. It will therefore also be understood that the expression "optical lighting" refers to lighting that serves the purpose of visibly illuminating some object or area, or that serves as a visible signal to an onlooker. This can comprise both direct lighting (such as one obtains with, for example, a naked light bulb) and indirect lighting (such as one obtains with, for example, diffused lighting, backlighting, and so forth).

[0018] This process 100 also makes provision for providing 103 a source of optically- encoded data. This can comprise, for example, methodologies that rapidly switch a light source (such as a laser of a particular frequency) on and off to thereby indicate binary- encoded information. This can also comprise Pulse Amplitude Modulation (PAM) and/or Quadrature Amplitude Modulation (QAM) as disclosed in the aforementioned application entitled METHOD AND APPARATUS TO FACILITATE TRANSMITTING DATA USING MULTIPLE OPTICAL DATA STREAMS.

[0019] By one approach, this step of providing 103 a source of optically-encoded data can comprise providing a plurality of sources of differing optically-encoded data streams. As a simple non-limiting illustration in this regard, this could comprise providing a first source of optically-encoded data for a temperature sensor and a second source of optically-encoded data for an airspeed sensor. These data streams may relate to one another with respect to the data being borne, or not, as desired. These teachings will also accommodate using different encoding technologies for at least some of these optically-encoded data streams. As a simple non-limiting illustration in this regard, the aforementioned first source of optically-encoded data may utilize an encoding scheme using a first duration of time to signify a "1" while the aforementioned second source of optically-encoded data may utilize an encoding scheme that uses a second duration of time to signify a "1," which second duration of time is different than the first duration of time.

[0020] In any event, this process 100 then provides for multiplexing 104 the optical power, the optical lighting, and the optically-encoded data in a shared optical conduit. By one approach, this multiplexing comprises Frequency Division Multiplexing (FDM). By this approach, though occupying the same optical conduit at a same point in time, these different light beams occupy differing frequencies (which may comprise differing frequency bands). For some application purposes it may be possible for these different bands to overlap with one another to small extent. In general, however, most designers will likely prefer to avoid such overlap to thereby avoid any potentially confusing crosstalk. It would also be possible to interleave the utilized frequencies if desired.

[0021] The shared optical conduit can also vary with the application setting. In some cases, the shared optical conduit may comprise free space. In other cases, the shared optical conduit can comprise a bounded conduit such as a light pipe, a flexible optical fiber (either comprised of glass, plastic, or the like), and so forth.

[0022] So configured, those skilled in the art will recognize and appreciate that up to a three-fold reduction in required conduit resources (such as required fibers) may be realized via these teachings while nevertheless satisfying corresponding demands for light-based power, lighting, and data transmissions. This, in turn, can greatly facilitate the ease and cost effectiveness by which a light-based operational architecture can be adopted for use in a given application setting such as a vehicle or building.

[0023] Those skilled in the art will appreciate that the above-described processes are readily enabled using any of a wide variety of available and/or readily configured platforms, including partially or wholly programmable platforms as are known in the art or dedicated purpose platforms as may be desired for some applications. Referring now to FIG. 2, an illustrative approach to such a platform will now be provided.

[0024] In this illustrative approach, a beam multiplexer 201 is operably coupled to and receives light inputs from the light sources described above. This comprises, in this example, optical power ("P") 203 as provided by a corresponding optical power source 202, optical lighting ("L") 205 as provided by an optical lighting source 204, and first optically- encoded data ("ID") 207 as provided by a first optically-encoded data source 206.

[0025] As noted above, these teachings will readily accommodate multiple sources of optically-encoded data streams. This is represented here by the inclusion of an optional Nth optically-encoded data source 208 that provides Nth optically-encoded data ("ND") 209 to the beam multiplexer 201. (Those skilled in the art will recognize that "N" comprises an integer greater than one.) And again, these multiple sources of optically-encoded data can be as contextually or substantively related, or as unrelated, as may be desired.

[0026] The beam multiplexer 201 is configured and arranged to multiplex the optical power 203, the optical lighting 205, and the optically-encoded data 207, 209 together and to output that aggregated content to an optical conduit 210 of choice (represented here by a plastic optical fiber, though again numerous other choices presently exist in this regard and other possibilities are likely to be developed going forward).

[0027] As suggested above, and as shown in this illustrative example, these various light beams occupy different frequency bands and hence the multiplexing comprises Frequency Division Multiplexing. As a more specific example in this regard, the optical lighting 203 can be comprised of light having a frequency that ranges from about 400 nanometers to about 750 nanometers, the optical power lighting 205 can be comprised of light having a frequency that ranges from about 800 nanometers to about 850 nanometers, and the optically-encoded data 207, 209 can be comprised of light having a frequency that ranges from about 900 nanometers to about 1,500 nanometers. Those skilled in the art will appreciate and recognize that the use of such an example is intended to serve only as an illustrative example and is not intended to serve as an exhaustive or otherwise limiting example in this regard.

[0028] These various light beams can be directed, accessed, diverted, de-multiplexed, and otherwise employed as desired by tapping into the optical conduit 210. As one simple illustrative example in this regard, and referring now to FIG. 3, a terminus of the optical conduit 210 can comprise a beam demultiplexer 301 that demultiplexes the incoming light beams and directs them accordingly. In the example shown, the optical power light beam 203 is directed to a corresponding power application 303 (which may comprise, for example, gallium arsenide (GaAs)-based solar cells to convert the incoming optical power light beam 203 into electricity as is known in the art), the optical lighting light beam 205 is directed to a corresponding lighting application 302 (which might comprise, in this example, a backlight application for a dynamic Liquid Crystal Display (LCD)), and the optically-encoded data light beams 207, 209 are directed to one or more corresponding data applications 304 where the light beams 207, 209 are sensed and the modulated data demodulated to permit its recovery and usage.

[0029] Such applications are, in and of themselves, known in the art and numerous other examples exist in this regard and are also well known to those skilled in the art. As these teachings are not particularly sensitive to any particular selections in this regard, for the sake of brevity further elaboration in this regard will not be provided here.

[0030] The beam demultiplexer 301 can be configured using any of a variety of known techniques and approaches. For example, the optical power light beam 205, being comprised in this example of infrared light, can be separated from the optical lighting light beam 203 by use of a cold mirror.

[0031] It would also be possible to employ one or more beam splitters to separate these various light beams from one another. As those skilled in the art are aware, a beam splitter comprises a device that splits incoming light into two different paths (which are typically orthogonal to one another). Beam splitters are readily designed to occasion this split at a particular frequency of choice, such that light having a wavelength shorter than the frequency of choice will continue along one path while light having a longer wavelength than the frequency of choice will be diverted along the second path. If desired, a plurality of beam splitters can be employed, in serial fashion, to split and to then split again the incoming light to provide for the demultiplexed light beams described above.

[0032] Those skilled in the art will recognize that a wide variety of modifications, alterations, and combinations can be made with respect to the above described embodiments without departing from the spirit and scope of the invention, and that such modifications, alterations, and combinations are to be viewed as being within the ambit of the inventive concept.

Claims

We claim:

1. A method comprising: providing a source of optical power; providing a source of optical lighting; providing a source of optically-encoded data; multiplexing the optical power, the optical lighting, and the optically-encoded data in a shared optical conduit.

2. The method of claim 1 wherein the optical power comprises, at least in part, infrared light.

3. The method of claim 1 wherein the optical lighting comprise, at least in part, backlighting.

4. The method of claim 1 wherein: providing a source of optically-encoded data comprises providing a plurality of sources of differing optically-encoded data streams; and multiplexing comprises multiplexing the optical power, the optical lighting, and the differing optically-encoded data streams.

5. The method of claim 1 wherein multiplexing the optical power, the optical lighting, and the optically-encoded data in a shared optical conduit comprise using frequency division multiplexing.

6. The method of claim 5 wherein using frequency division multiplexing comprises using frequencies of about 400 nanometers to about 750 nanometers for the optical lighting

7. The method of claim 6 wherein using frequency division multiplexing comprises using frequencies of about 800 nanometers to about 850 nanometers for the optical power.

8. The method of claim 7 wherein using frequency division multiplexing comprises using frequencies of about 900 nanometers to about 1,500 nanometers for the optically-encoded data.

9. The method of claim 1 wherein the shared optical conduit comprises an optical fiber.

10. The method of claim 9 wherein the optical fiber comprises a plastic optical fiber.

11. A apparatus comprising: an optical conduit; a source of optical power; a source of optical lighting; a source of optically-encoded data; a multiplexer operably coupled to the optical conduit, the source of optical power, the source of optical lighting, and the source of optically-encoded data, and wherein the multiplexer is configured and arranged to multiplex the optical power, the optical lighting, and the optically-encoded data together in the optical conduit.

12. The apparatus of claim 11 wherein the optical power comprises, at least in part, infrared light.

13. The apparatus of claim 11 wherein the optical lighting comprise, at least in part, backlighting.

14. The apparatus of claim 11 wherein: the source of optically-encoded data comprises a plurality of sources of differing optically-encoded data streams; and the multiplexer is configured and arranged to multiplex by multiplexing the optical power, the optical lighting, and the differing optically-encoded data streams together in the optical conduit.

15. The apparatus of claim 11 wherein the multiplexer is configured and arranged to multiplex the optical power, the optical lighting, and the optically-encoded data by using frequency division multiplexing.

16. The apparatus of claim 15 wherein the multiplexer is configured and arranged to use frequency division multiplexing by using frequencies of about 400 nanometers to about 750 nanometers for the optical lighting

17. The apparatus of claim 16 wherein the multiplexer is configured and arranged to use frequency division multiplexing by using frequencies of about 800 nanometers to about 850 nanometers for the optical power.

18. The apparatus of claim 17 wherein the multiplexer is configured and arranged to use frequency division multiplexing by using frequencies of about 900 nanometers to about 1,500 nanometers for the optically-encoded data.

19. The apparatus of claim 11 wherein the optical conduit comprises an optical fiber.

20. The apparatus of claim 19 wherein the optical fiber comprises a plastic optical fiber.