阅读说明：本技术 经由波导的多通道光通信 (Multi-channel optical communication via waveguides ) 是由 A·亨特 A·克里斯滕松 于 2020-03-11 设计创作，主要内容包括：实现光通信的设备使用波导来有效地收集用于光通信的波长特定的光并将所收集的光传播到传感器。更特别地,包括多个波长并且从一个或多个入口收集的光沿着TIR波导传播直到被散射元件扰乱,该散射元件有效地将传播的光引导到一个或多个传感器。每个传感器检测多个波长的子集。这样做时,例如通过将从多个不同的位置收集的光提供给单个传感器,本文提出的解决方案增加了可用于光通信的光量和/或减少了光通信所需的传感器数量。本文提出的波导解决方案可以在设备的内部和/或沿着设备的外表面(例如,外壳或外罩)实现。(Devices that enable optical communication use waveguides to efficiently collect wavelength-specific light for optical communication and propagate the collected light to sensors. More particularly, light that includes multiple wavelengths and is collected from one or more inlets propagates along the TIR waveguide until disturbed by a scattering element that effectively directs the propagating light to one or more sensors. Each sensor detects a subset of the plurality of wavelengths. In doing so, the solution presented herein increases the amount of light available for optical communication and/or reduces the number of sensors needed for optical communication, for example, by providing light collected from multiple different locations to a single sensor. The waveguide solutions presented herein may be implemented inside the device and/or along an outer surface (e.g., housing or enclosure) of the device.)

1. A detection system for optical communication, the detection system comprising:

a total internal reflection, TIR, waveguide comprising:

a first structure having a first refractive index, wherein a second refractive index adjacent the first structure is less than the first refractive index such that light for optical communication input to the TIR waveguide propagates within the first structure along the TIR waveguide, the light comprising a plurality of wavelengths;

a scattering element disposed at a first location of the TIR waveguide along an inner edge of the first structure, the scattering element configured to disrupt propagation of the light along the TIR waveguide; and

one or more waveguide inlets, each waveguide inlet at a corresponding second location, wherein each second location is offset from the first location along the TIR waveguide, each of the one or more waveguide inlets configured to:

collecting light associated with the optical communication; and

inputting the collected light to the first structure at a corresponding second location; and

one or more light sensors disposed proximate an edge of the first structure opposite the first location and each spaced from the scattering element by a thickness of the first structure, wherein each of the one or more light sensors detects a subset of the plurality of wavelengths of the disrupted light, the subset of the plurality of wavelengths including one or more wavelengths that collectively are less than the plurality of wavelengths.

2. The detection system of claim 1, wherein:

the one or more light sensors comprise one or more wavelength-specific light sensors; and

each of the one or more wavelength-specific light sensors is configured to detect a different subset of the plurality of wavelengths.

3. The detection system of claim 1, wherein at least one of the one or more waveguide inlets includes a wavelength-specific element configured to collect wavelength-specific light corresponding to a subset of the plurality of wavelengths for input into the first structure.

4. The detection system of claim 3, wherein the one or more light sensors comprise one or more wavelength-specific light sensors, wherein each of the one or more wavelength-specific light sensors is configured to detect a different wavelength of the one or more wavelengths of the subset of the plurality of wavelengths.

5. A detection system according to claim 3, wherein the wavelength-specific element comprises a wavelength-specific filter.

6. The detection system of claim 3, wherein the wavelength-specific element comprises a prism configured to split the collected light so as to input the wavelength-specific light into the first structure.

7. The detection system of claim 1, wherein:

the TIR waveguide includes one waveguide entrance and a plurality of paths that originate at the one waveguide entrance and are physically spaced apart from one another;

each path of the plurality of paths corresponds to a different subset of the plurality of wavelengths;

the one waveguide inlet includes wavelength-specific elements configured to input wavelength-specific light corresponding to each of the different subsets into a corresponding path of the plurality of paths of the TIR waveguide.

8. The detection system of claim 7, wherein:

each of the different subsets comprises a different wavelength of the plurality of wavelengths;

the wavelength specific element comprises a prism configured to separate light collected at the one waveguide entrance into each different wavelength of the plurality of wavelengths; and

wherein each of the plurality of paths originates at the one waveguide entrance and is physically spaced apart from each other so as to be aligned with an output angle of the prism such that each of the plurality of paths receives wavelength-specific light associated with a different one of the plurality of wavelengths.

9. The detection system of claim 1, wherein the TIR waveguide is configured to collect, propagate, and disturb wavelength-specific light corresponding to a subset of the plurality of wavelengths.

10. The detection system of claim 1, wherein the detection system is part of a portable device configured to be worn by a user.

11. A method of detecting light associated with optical communications, the method comprising:

collecting light configured for the optical communication via one or more waveguide inlets arranged at different first locations along a Total Internal Reflection (TIR) waveguide, the light comprising a plurality of wavelengths, and the TIR waveguide comprising a first structure having a first refractive index, wherein a second refractive index adjacent the first structure is less than the first refractive index, such that light entering the TIR waveguide propagates along the TIR waveguide within the first structure;

perturbing propagation of the light along the TIR waveguide using a scattering element disposed at a second location of the TIR waveguide along the inner edge of the first structure that is offset from each of the one or more first locations along the TIR waveguide; and

detecting the perturbed light using one or more light sensors disposed proximate an edge of the first structure opposite the second location and spaced from the scattering element by a thickness of the first structure, wherein each of the one or more light sensors detects a subset of the plurality of wavelengths of the perturbed light, the subset of the plurality of wavelengths including one or more wavelengths that collectively are less than the plurality of wavelengths.

12. The method of claim 11, wherein:

the one or more light sensors comprise one or more wavelength-specific light sensors; and

the detecting the disturbed light comprises: detecting a different subset of the plurality of wavelengths using each of the one or more wavelength-specific light sensors.

13. The method of claim 1, wherein:

at least one of the one or more waveguide inlets comprises a wavelength-specific element configured to collect wavelength-specific light corresponding to a subset of the plurality of wavelengths; and

the collecting the light comprises: inputting the wavelength specific light into the first structure.

14. The method of claim 13, wherein:

the one or more light sensors comprise one or more wavelength-specific light sensors; and

the detecting the disturbed light comprises: detecting a different wavelength of the one or more wavelengths of the subset of the plurality of wavelengths using each of the one or more wavelength specific light sensors.

15. The method of claim 13, wherein:

the wavelength specific element comprises a wavelength specific filter; and

the collecting the light comprises: filtering the light configured for the optical communication to input the wavelength specific light into the first structure.

16. The method of claim 13, wherein:

the wavelength-specific element comprises a prism configured to separate the light configured for the optical communication into wavelength-specific light; and

the collecting the light comprises: inputting the wavelength specific light into the first structure.

17. The method of claim 11, wherein:

the TIR waveguide includes one waveguide entrance and a plurality of paths that originate at the one waveguide entrance and are physically spaced apart from one another;

each path of the plurality of paths corresponds to a different subset of the plurality of wavelengths;

the collecting the light comprises: inputting wavelength-specific light corresponding to each of the different subsets into a corresponding path of the plurality of paths of the TIR waveguide.

18. The method of claim 17, wherein:

each of the different subsets comprises a different wavelength of the plurality of wavelengths;

the inputting the wavelength-specific light includes:

separating the light configured for optical communication into each different wavelength of the plurality of wavelengths at the one waveguide entrance; and

inputting each different wavelength of the plurality of wavelengths into a corresponding one of the different paths of the TIR waveguide.

Background

WiFi is a wireless technology that uses electromagnetic waves to wirelessly connect multiple devices within a particular area to each other and/or to connect one or more wireless devices within a particular area to the internet. While WiFi has been very useful and popular in recent years, it is expected that the demand for more bandwidth will soon lead to replacement or supplementation of WiFi with alternative wireless technologies.

Optical fidelity (LiFi), which uses light in a specific wavelength range for local area wireless communication, represents an alternative wireless technology that can replace or supplement WiFi. The LiFi system relies on visible, infrared and/or near ultraviolet spectral waves. By modulating the light source (e.g., light emitting diode), the LiFi emitter sends a high speed signal that is detectable by the photodetector. The photodetector converts the detected light into an electrical current, which is further processed by a receiver to interpret the detected light.

The visible spectrum is-10,000 times larger than the radio frequency spectrum. Thus, LiFi is expected to increase the bandwidth achievable by WiFi alone by a factor of 100. Furthermore, LiFi tends to be more suitable for high density and/or high interference environments, such as airplanes, office buildings, hospitals, power plants, and the like. Accordingly, there has recently been considerable interest in improving and/or adapting the LiFi technology for specific applications and/or devices.

Disclosure of Invention

The solution proposed herein uses a waveguide to efficiently collect light (particularly wavelength specific light) for optical communication and propagate the collected light to a sensor to enable wavelength specific detection. Such wavelength-specific light collection may involve filtering the light at the waveguide entrance to direct wavelength-specific light to the sensor, directing the collected light to the wavelength-specific sensor, and/or filtering the light at the sensor such that the sensor detects only the desired wavelength. As used herein, "wavelength-specific" refers to one or more peak wavelengths having the largest amplitude of a range of wavelengths. Thus, it will be understood that references to "wavelength specific" generally include some number of wavelengths in addition to the peak wavelength, e.g., wavelengths around each peak wavelength.

The solution proposed herein increases the amount of light available for optical communication, in particular wavelength specific optical communication, even when the light associated with the optical communication enters the device at an angle. Furthermore, the solution presented herein reduces the number of sensors required for optical communication, since multiple waveguides can direct light from multiple collection points to a single sensor. The waveguide solutions presented herein may be implemented inside the device and/or along an outer surface (e.g., housing or enclosure) of the device. As such, the solutions presented herein also enable optical communication for implementation in a wide variety of devices (e.g., cellular phones, tablet computers, smartphones, smartwatches, smart glasses, etc.) and/or a wide variety of scenarios.

One exemplary embodiment includes a detection system for optical communications. The detection system includes a Total Internal Reflection (TIR) waveguide and one or more light sensors. The TIR waveguide comprises a first structure, a scattering element, and one or more waveguide inlets. The first structure has a first refractive index, wherein a second refractive index adjacent the first structure is less than the first refractive index such that light input to the TIR waveguide for optical communication propagates along the TIR waveguide within the first structure, and wherein the light comprises a plurality of wavelengths. The scattering element is disposed at a first location of the TIR waveguide along an inner edge of the first structure and is configured to disrupt propagation of light along the TIR waveguide. Each waveguide inlet of the one or more waveguide inlets is at a corresponding second location, wherein each second location is offset from the first location along the TIR waveguide. Each of the one or more waveguide inlets is configured to collect light associated with the optical communication and input the collected light to the first structure at a corresponding second location. The one or more light sensors are disposed adjacent an edge of the first structure opposite the first location, and each light sensor is spaced from the scattering element by a thickness of the first structure. Each of the one or more light sensors detects a subset of a plurality of wavelengths of the perturbed light, wherein the subset of the plurality of wavelengths includes one or more wavelengths that collectively are less than the plurality of wavelengths.

One exemplary embodiment includes a method of detecting light associated with optical communications. The method includes collecting light configured for optical communication via one or more waveguide inlets, wherein the one or more waveguide inlets are arranged at different first locations along a Total Internal Reflection (TIR) waveguide, the light comprising a plurality of wavelengths. The TIR waveguide includes a first structure having a first refractive index, wherein a second refractive index adjacent the first structure is less than the first refractive index such that light entering the TIR waveguide propagates along the TIR waveguide within the first structure. The method also includes disrupting the propagation of light along the TIR waveguide using a scattering element disposed at a second location of the TIR waveguide along the inner edge of the first structure, wherein the second location is offset from each of the one or more first locations along the TIR waveguide. The method also includes detecting the perturbed light using one or more light sensors, wherein the one or more light sensors are disposed adjacent an edge of the first structure opposite the second location and spaced from the scattering element by a thickness of the first structure, each of the one or more light sensors detecting a subset of the plurality of wavelengths of the perturbed light, and wherein the subset of the plurality of wavelengths includes one or more wavelengths that collectively are less than the plurality of wavelengths.

According to an exemplary embodiment, the detected light is processed according to any known means to determine information transmitted in the light collected by the detection system and to communicate this information (where appropriate) to the user.

Drawings

Fig. 1 shows an exemplary waveguide-based light detection system according to an exemplary embodiment of the solution presented herein.

Fig. 2 illustrates exemplary multiple wavelengths suitable for use in the light detection systems disclosed herein.

Fig. 3A-3B show top views of exemplary waveguide-based light detection systems according to exemplary embodiments of the solution proposed herein.

Fig. 4A-4B show a further exemplary waveguide-based light detection system according to an exemplary embodiment of the solution proposed herein.

Fig. 5 shows a top view of another exemplary waveguide-based light detection system according to an exemplary embodiment of the solution proposed herein.

Fig. 6 shows an exemplary waveguide-based light detection system according to another exemplary embodiment of the solution presented herein.

Fig. 7 shows an exemplary waveguide-based light detection system according to another exemplary embodiment of the solution presented herein.

Fig. 8 shows an exemplary waveguide-based light detection system according to another exemplary embodiment of the solution presented herein.

Fig. 9 shows an exemplary waveguide-based light detection system according to another exemplary embodiment of the solution presented herein.

Fig. 10 shows an exemplary method for detecting light for optical communication according to an exemplary embodiment of the solution presented herein.

Fig. 11A-11C show an exemplary device comprising a light detection system according to an exemplary embodiment of the solution proposed herein.

Fig. 12 shows an exemplary device comprising a light detection system according to another exemplary embodiment of the solution presented herein.

Fig. 13 shows an exemplary device comprising a light detection system according to another exemplary embodiment of the solution presented herein.

Detailed Description

The use of optical communication (e.g., LiFi, along with or as an alternative to WiFi) has expanded the capabilities of local wireless communication. However, it is generally preferred that the equipment used for such communication is small and has limited space available for the detector/receiver used for such communication. Furthermore, as the size of these devices continues to decrease and/or new features and/or hardware continues to be added to these devices, the space available in these devices continues to decrease. For example, wearable devices (e.g., glasses, watches, etc.) are designed with a minimum size to improve their wearability (e.g., making them lighter, more comfortable, etc.). The limited physical size of many devices imposes limitations on the location and/or size and/or number of light sensors that may be included in a device for optical communication, particularly when combined with all of the functionality intended to be included in such a device.

Conventional solutions require a sensor for each light capture/entrance location of the device. For example, a device that enables optical communication may include three openings on a housing of the device, where such openings are intended or used to receive external light associated with the optical communication. In conventional solutions, such a device must comprise three sensors, one arranged below each of the three openings, to capture the light entering each opening. Because many devices have limited space available for such sensors, such conventional solutions severely limit the number of sensors that can be used for optical communication and, thus, the amount of light that can be collected for optical communication and/or the effectiveness of optical communication. Furthermore, conventional solutions often have challenging mechanical requirements with respect to the position of the sensor and/or the alignment of the sensor with the corresponding opening in order to enable the sensor to capture as much light as possible into the opening. These mechanical limitations can severely limit the location options for the opening.

The solution presented herein solves many of the problems associated with conventional solutions by using a waveguide to guide light from one or more openings to a sensor to facilitate wavelength-specific optical communication. In doing so, the solution presented herein reduces the number of sensors used for optical communication, enables each sensor to capture more light associated with optical communication, and/or enables flexibility with respect to sensor size, sensor location in the device, and/or alignment of the sensor with any particular opening. In particular, the solution presented herein enables any number of openings to be placed at any location on the device, while also enabling one or more sensors to be placed at any suitable location within the device, which improves signal quality and reduces mechanical limitations associated with LiFi.

Fig. 1 shows an exemplary light detection system 100 for optical communication, wherein the light for optical communication comprises a plurality of peak wavelengths, e.g. λ, according to an embodiment of the solution proposed herein₁-λ_NFor example, as shown in fig. 2. The light detection system 100 includes a waveguide 110 and one or more light sensors 130. Waveguide 110 includes a Total Internal Reflection (TIR) structure 112 through which light propagates, a scattering element 114, and one or more waveguide inlets 116. The TIR structure 112 has a first index of refraction n₁Wherein the refractive index (e.g., n) surrounding/adjacent to TIR structure 112₂And/or n₃) Less than the first refractive index n₁Such that light input to waveguide 110 propagates along waveguide 110 within TIR structure 112. Scattering elements 114 are disposed at predetermined locations of waveguide 110 along the inner edge of TIR structure 112 to disrupt the propagation of light along TIR structure 112. Each waveguide entrance 116 of the one or more waveguide entrances 116 is at a location laterally offset from the location of the scattering element 114 along the waveguide 110, where each waveguide entrance 116 collects light 140 associated with optical communication and inputs the collected light 140 into the TIR structure 112 at a corresponding input location. Each of the one or more photosensors 130 detects a plurality of wavelengths λ₁-λ_NIs given as a subset of_m-λ_MWherein ((M-M) +1) < N. To this end, the light sensor 130 is arranged adjacent an inner edge of the TIR structure 112 opposite the position of the scattering element 114 and is typically spaced from the scattering element 114 by the thickness t of the TIR structure 112 such that the light sensor 130 detects light disturbed by the scattering element 114. For example, each sensor 130 of the one or more light sensors 130 may include a light sensitive receiver (PSR) configured to detect wavelength-specific light that is disturbed by the scattering element 114.

The propagation of light through the TIR structure 112 is at least partially influenced by the refractive index n of the TIR structure 112₁Relative to one or more folds of the surroundingsAnd controlling the refractive index. When the material surrounding TIR structure 112 has a lower index of refraction than TIR structure 112, TIR structure 112 acts as a TIR layer, which enables light entering TIR structure 112 at the TIR angle to propagate along TIR structure 112 with minimal or no loss as a result of total internal reflection. Although in some embodiments the refractive indices around TIR structures 112 are all the same, the solution presented herein does not require that the refractive indices around TIR structures 112 be equal. In contrast, the solution presented herein requires only the refractive index n of the TIR structure 112₁Greater than each of the refractive indices of the surrounding materials, such that light input into the TIR structure 112 propagates along the TIR structure 112 with total internal reflection.

The desired refractive index relationship between TIR structure 112 and the surrounding structures/materials may be achieved in a variety of ways. For example, when the TIR structure 112 is of a first refractive index n₁Of a cylindrical tube, a second refractive index n around the tube₂Less than the first refractive index n₁(n₂<n₁) Resulting in the expected total internal reflection within TIR structure 112. In another example, when TIR structure 112 is of a first refractive index n₁A right-angle rectangular prism, as shown in fig. 1, a second index of refraction n on one side of the TIR structure 112₂Less than the first refractive index (n)₂<n₁) And a third index of refraction n on an opposite side of TIR structure 112₃Is also smaller than the first refractive index (n)₃<n₁) Resulting in total internal reflection within TIR structure 112. In another example, waveguide 110 may be implemented using a set of coatings or layers, where each layer/coating represents a different portion of waveguide 110. In this example, one layer may represent a TIR layer (i.e., TIR structure 112), while one or more layers surrounding the TIR layer have a lower index of refraction than the TIR layer, and thus represent "reflective" layers. Such a reflective layer may also serve as a protective layer to protect TIR structure 112 from scratches, debris, and/or other foreign objects. Alternatively, a protective layer separate from the reflective layer may be applied between the TIR structure 112 and the reflective layer, wherein the protective layer has the same or lower refractive index as the reflective layer. The protective layer may also be used to add printed matter (e.g., text, images, etc.) when the printed matter is printed againstThe user of device 200, when visible, identifies any desired information related to device 200 or about device 200, such as brand name, model name/number, team affiliation, school affiliation, and the like.

Scattering element 114 comprises any material or structure that disrupts the propagation of light within TIR structure 112. In some embodiments, the scattering element 114 may direct the disturbed light to the sensor 130. In other embodiments, the scattering element 114 may scatter light such that at least some of the initially propagated light is captured by the sensor 130. In one exemplary embodiment, scattering element 114 comprises a white or colored paint applied over inner edge sensor 130 of TIR structure 112. In another exemplary embodiment, the scattering element 114 is constructed by altering the material at the location of the scattering element 114 so that the location of the TIR structure 112 is no longer flat and/or smooth. For example, machining points may be placed at the location of the scattering region 114 or the location of the scattering region 114 may be etched or roughened.

As described above, each of the one or more light sensors 130 detects a plurality of wavelengths λ₁-λ_NIs given as a subset of_m-λ_MWherein ((M-M) +1) < N. The plurality of wavelengths includes a plurality of peak wavelengths suitable for optical communication, for example, 429nm, 509nm, 564nm, 611nm, 656nm, 703nm, and 753nm, as shown in fig. 2. In some embodiments, multiple wavelengths λ₁-λ_NEach subset λ of_m-λ_MOne of the plurality of peak wavelengths, or a plurality of peak wavelengths of the plurality of peak wavelengths may be included. For example, the first subset may include 429nm, the second subset may include 509nm and 564nm, and so on. It will further be appreciated that some of the subsets may overlap such that a particular peak wavelength is part of two or more of the subsets. Further, it will be understood that the subset may include additional non-peak wavelengths, e.g., wavelengths around the peak wavelength, and that the solution presented herein is described in terms of a subset of one or more peak wavelengths and/or as wavelength specific, where "wavelength specific" refers to one or more peak wavelengths in a particular subsetWavelength, but does not exclude the presence of other surrounding non-peak wavelengths.

Each sensor 130 of the one or more sensors 130 in the solution presented herein may detect a particular subset of the plurality of wavelengths in any number of ways. In one exemplary solution, each sensor 130 may be wavelength specific such that each sensor 130 is configured to detect a specific subset of the plurality of wavelengths. For example, as shown in the top view of fig. 3A-3B, one sensor for each subset of the plurality of wavelengths may be arranged opposite the scattering element 114 such that each sensor 130 detects only the corresponding peak wavelength. In the example of FIG. 3A, each sensor detects one of the peak wavelengths of FIG. 2, e.g., sensor 130₁429nm, sensor 130₂509nm, sensor 130₃Detecting 564nm, sensor 130₄611nm, sensor 130₅Detect 656nm, sensor 130₆Detect 703nm, sensor 130₇And detecting at 753 nm. It will be appreciated that more sensors 130 may be used if there are more peak wavelengths, and fewer sensors 130 may be used if there are fewer peak wavelengths to detect or if each subset includes multiple peak wavelengths. For example, FIG. 3B shows one exemplary embodiment comprising four sensors, wherein each of the four sensors is disposed opposite to scattering element 114, and wherein sensor 130₁429nm, sensor 130₂509nm and 564nm, sensor 130₃611nm and 656nm, sensor 130₄Detection was at 703nm and 753 nm. Thus, it will be appreciated that the solution presented herein allows for more or fewer sensors, depending on the number of wavelength subsets.

Although the figures used to illustrate embodiments of the solution presented herein show a hexagonal sensor 130, it will be understood that the sensor 130 is not limited to a hexagonal shape. Each sensor 130 may be any shape and/or size, wherein the shape and/or size is generally defined based on space limitations and/or manufacturer parameters. Further, the sensors 130 used in the solution presented herein need not all be of the same size or shape. Still further, it will be understood that the solution presented herein does not require that each sensor 130 abut one or more of the other sensors 130, as shown in fig. 3A-3B; the sensors 130 may be arranged in any suitable manner opposite the scattering element 114 such that each sensor 130 detects its corresponding subset of the plurality of wavelengths.

In another exemplary embodiment, light to each sensor 130 may first pass through the wavelength-specific element 117, for example at the waveguide entrance 116 (as shown in fig. 4A) and/or at the location of the sensor 130 (as shown in fig. 4B), such that the light input to the sensor 130 includes only the wavelengths in the corresponding subset. In such exemplary embodiments, the sensor 130 for collecting light that is disturbed by the scattering element 114 may also be wavelength specific or may be capable of detecting any number of wavelengths, including but not limited to wavelengths in a corresponding subset.

Fig. 4A shows an exemplary embodiment, wherein the wavelength specific element 117 is a filter 117 arranged at the waveguide entrance 116, wherein the filter 117 is configured such that the peak wavelength λ in a specific wavelength subset is_m-λ_MBy simultaneously blocking the remaining peak wavelengths of the plurality of wavelengths. In this embodiment, the wavelength λ_m-λ_MPropagate along the waveguide 110 until they are disturbed by the scattering element 114 and detected by the corresponding sensor 130. As shown in fig. 4B, the filter 117 may alternatively or additionally be arranged adjacent to the sensor 130, wherein wavelengths captured at the waveguide entrance 116 propagate along the waveguide 110, but only a subset of wavelengths λ_m-λ_MBy reaching sensor 130 and being detected by sensor 130.

Fig. 5 shows another exemplary embodiment of the solution proposed herein, wherein the wavelength specific element 117 is a prism 117. Exemplary prisms include, but are not limited to, a dispersive prism (e.g., a refractive prism or a diffraction grating) or a reflective prism. In this embodiment, prism 117 separates the input light into separate wavelength subsets, where each subset is input into subset-specific waveguide 110. For example, if inputtingThe light has seven peak wavelengths λ₁-λ_NThe prism 117 may split the input light into seven different directions, where each direction corresponds to one of the peak wavelengths, such that each peak wavelength is input into a separate waveguide 110 for detection by the sensor 130. For the example in fig. 5, this would result in λ₁Is input to the waveguide 110₁By the sensor 130₁Detection, λ₂Is input to the waveguide 110₂By the sensor 130₂Detection, λ₃Is input to the waveguide 110₃By the sensor 130₃Detection, λ₄Is input to the waveguide 110₄By the sensor 130₄Detection, λ₅Is input to the waveguide 110₅By the sensor 130₅Detection, λ₆Is input to the waveguide 110₆By the sensor 130₆Detection, λ₇Is input to the waveguide 110₇By the sensor 130₇And (6) detecting. It will be appreciated that additional waveguides 110 and sensors 130 may be used if there are more than seven peak wavelengths, while fewer waveguides 110 and sensors 130 may be used if there are less than seven peak wavelengths and/or one or more subsets include multiple peak wavelengths. Further, while fig. 5 shows a top view of an exemplary prism solution (where the prism 117 fans out each subset in one plane), it will be understood that the prism 117 may be configured to separate wavelengths in any suitable manner and/or in any suitable direction, and the solutions presented herein will configure the orientation of the waveguide 110 relative to the prism 117 and the waveguide inlet 116 as appropriate, such that the waveguide 110 receives and directs the corresponding wavelength subset to the corresponding sensor 130.

Further details regarding how light enters the device and is directed to the sensor 130 are provided below. It will be understood that these details apply to any individual peak wavelength, subset of peak wavelengths, and/or multiple peak wavelengths that are separated at some point in the detection system 100 (e.g., at the waveguide entrance 116, at the sensor 130, etc.). As such, the wavelength specific aspects described above apply to each of the multiple openings, multiple sensors, multiple directions, light guide elements, etc., discussed further below.

As described above, light enters the waveguide 110 after first entering the waveguide entrance 116. Each waveguide entrance 116 comprises an opening in the housing of the device 200 configured to collect light 140 associated with, for example, optical communication and input the collected light into the TIR structure 112 of the waveguide 110. Each waveguide entrance 116 is laterally offset from the position of the scattering element 114/sensor 130, wherein light 140 collected at one entrance propagates along the waveguide 110 to reach the sensor 130. In some embodiments, the waveguide inlet 116 may include only an opening. In other embodiments, the waveguide entrance 116 may include a collection element 124, such as a lens or lens system (e.g., fig. 7), wherein the collection element 124 is configured to increase the amount of external light 140 input into the waveguide 110. When the waveguide entrance 116 includes a collection element 124, typically the collection element 124 will have a wide field of view (FoV) to increase the amount of light collected. Exemplary lenses include, but are not limited to, a Fresnel lens 124a (FIG. 8), a plano-convex lens 124b (FIG. 8), and the like. It will be appreciated that the use of any collection elements 124 in one or more waveguide inlets 116 is optional.

Waveguide 110 may also include a light guiding element 118 opposite the corresponding waveguide entrance 116 configured to facilitate propagation of light collected from waveguide entrance 116 along TIR structure 112. In one exemplary embodiment, light-guiding elements 118 include reflectors configured to reflect light collected by corresponding waveguide inlets 116 at total internal reflection angles to facilitate propagation of the collected light along TIR structure 112. One exemplary reflector includes an angled mirror 118, as shown in FIG. 6, that reflects incident light at an angle θ equal to the incident angle θ. To achieve total internal reflection, this angle θ may be equal to the total internal reflection angle for the waveguide 110. Additional reflectors include, but are not limited to, multiple etched surfaces (as shown in FIG. 8), mirror printing, or materials with a lower index of refraction so that the angle θ of the light exiting the light guiding element 118 is the same as the angle of incidence on the light guiding element 118. In another exemplary embodiment, the light-guiding element 118 includes a bend proximate to the corresponding waveguide entrance 116, such as shown in fig. 7, wherein the bend is configured to guide the collected light at a total internal reflection angle to facilitate propagation of the collected light along the TIR structure 112.

The exemplary light detection system 100 of fig. 1 and 3-7 shows a single waveguide entrance 116 providing light to a single sensor 130. However, the solution presented herein is not limited thereto. Alternative embodiments may include multiple waveguide inlets 116 that collect light to propagate along one or more corresponding waveguides 110 to the sensor 130. In some embodiments, multiple waveguide inlets 116 use the same waveguide 110 to propagate light to a single sensor 130. In other embodiments, multiple waveguides 110 propagate light from one or more waveguide inlets 116 to a single sensor 130. Additionally, the position of one or more waveguide inlets 116 relative to the sensor may be selected to reduce noise and/or increase signal strength. For example, the lateral spacing between the plurality of waveguide inlets 116 and the corresponding sensors 130 may be configured such that light entering the sensors 130 is constructively increased. Alternatively or additionally, the lateral spacing between the plurality of waveguide inlets 116 and the corresponding sensors 130 may be configured such that interference present in the collected light increases destructively or neutrally.

Fig. 8-9 illustrate an exemplary embodiment having multiple waveguide inlets 116 that direct light to a single sensor 130. As shown in fig. 8, the light sensor 130 may detect light originating from a plurality of waveguide inlets 116 (e.g., a first waveguide inlet 116a and a second waveguide inlet 116b located on opposite sides of the TIR waveguide 110 as viewed from the light sensor 130). In this exemplary embodiment, waveguide entrance 116a and lens 124a collect light 140a, and light guiding element 118a establishes a TIR angle for the collected light to propagate 126a the collected light in a first direction along TIR structure 112 towards sensor 130. Further, waveguide entrance 116b and lens 124b collect light 140b, and light-guiding element 118b establishes a TIR angle for the collected light to propagate 126b the collected light along TIR structure 112 in a second direction opposite the first direction towards sensor 130. The scattering element 114 perturbs the propagation 126a, 126b of light collected by the waveguide inlets 116a, 116b from both directions for detection by the sensor 130.

In fig. 9, the light sensor 130 detects light originating from three waveguide inlets 116a, 116b, 116 c. In this exemplary embodiment, TIR waveguide 110 comprises a plurality of branches 110a, 110b, 110c, each propagating 126a, 126n, 126v light from a corresponding entrance 116a, 116b, 116a, respectively, in a different direction towards light sensor 130, wherein scattering element 114 perturbs the propagating light to enable detection by light sensor 130. It will be appreciated that the multiple branches 110a, 110b, 110c of fig. 9 may represent different waveguides 110 that collectively direct collected light to a single sensor 130.

Although the exemplary detection system 100 is shown with only one to three wavelength inlets 116, it will be understood that the detection system 100 disclosed herein may include any number of waveguide inlets 116. In general, the detection system 100 may include any number of waveguide inlets 116 and/or waveguides 110, wherein each inlet 116 is located at a position of the waveguide 110 that is laterally displaced from the sensor 130 and the scattering element 114, such that optical communication is achieved using fewer sensors 130 than waveguide inlets 116 and/or waveguides 110. In doing so, the solution presented herein reduces the number of sensors 130 associated with optical communication while improving the quality of the optical communication, for example, by increasing the amplitude of the detected light. Furthermore, by using waveguide 110 to guide light from multiple inlets 116 to sensor 130, the solution presented herein relaxes the previously imposed limitations on sensor 130, e.g., size, power, etc., as sensor 130 can now be placed at any suitable location in device 200.

Fig. 10 illustrates an exemplary method 300 of detecting light associated with optical communications. The method 300 includes collecting light configured for optical communication via one or more waveguide entrances 116, the one or more waveguide entrances 116 being disposed at different first locations along the Total Internal Reflection (TIR) waveguide 110 (block 310), wherein the light includes a plurality of wavelengths λ₁-λ_N. TIR waveguide 110 includes a first refractive index n₁Wherein a second refractive index n adjacent to the TIR structure 112₂And/or n₃Less than the first refractive index n₁Such that light entering TIR waveguide 110 propagates along TIR structure 112. The method 300 also includes disrupting the propagation of light along the TIR waveguide 110 using a scattering element 114, the scattering element 114 being disposed at a second location of the TIR waveguide 110 along an inner edge of the TIR structure 112 (block 320). The second location is offset (laterally) from each of the one or more first locations along TIR waveguide 110. The method 300 further includes detecting the disrupted light using one or more light sensors 130, the one or more light sensors 130 being disposed adjacent an edge of the TIR structure 112 opposite the second location and spaced apart from the scattering element 114 by a thickness t of the TIR structure 112 (block 330). Each of the one or more light sensors 130 detects a plurality of wavelengths λ of the disturbed light₁-λ_NIs given as a subset of_m-λ_MWherein the plurality of wavelengths λ₁-λ_NIs given as a subset of_m-λ_MIncludes one or more wavelengths that collectively are less than the plurality of wavelengths, i.e., ((M-M) +1) < N.

As mentioned above, the light detection system 100 of the solution presented herein may be implemented in and/or as part of any number of wireless devices 200 implementing optical communication. Exemplary device 200 may be worn and/or carried by a user, wherein light detection system 100 disclosed herein may be internal to a housing of device 200, partially disposed internal to device 200 and partially integrated with/disposed on a housing of device 200, or implemented on an outer surface of a housing of device 200.

Fig. 11A-11C illustrate an exemplary smartphone device 200. The smartphone device 200 may include a waveguide inlet 116 along the perimeter of the housing 210 around the display 220, as shown in fig. 11A and 11C. Alternatively or additionally, the device 200 may include a waveguide inlet on the back of the smartphone device 200 (as shown in fig. 11B), and/or a waveguide inlet integrated with the display 220 (as shown in fig. 11C). It will be understood that integration of the waveguide entry 116 with the display 220 may include placing the waveguide entry 116 under a transparent type of display 220 (e.g., an Active Matrix Organic Light Emitting Diode (AMOLED) screen/display). It will be further appreciated that the waveguide solution presented herein enables multiple waveguide portals 116 to be placed at any suitable location on the smartphone device 200, in addition to those explicitly shown, while enabling a single sensor 130 (or fewer sensors 130 than there are waveguide portals 116) to be placed at any location in the device 200 suitable for the sensor 130 to detect light from the multiple portals 116, thereby enabling optical communication.

In another exemplary embodiment, the device 200 comprises a watch, as shown in FIG. 12. For a watch embodiment, waveguide inlet 116 may be placed at any suitable location, for example, around face 230 and/or in a bezel of the watch, integrated with a display of the watch (not shown), as part of the face of the watch (not shown), etc. In yet another exemplary embodiment shown in fig. 13, the device 200 comprises eyeglasses, wherein the waveguide inlets 116 are arranged along a frame 240 of the eyeglasses. In addition to the implementations of smartphones, watches, and glasses discussed herein, the solution presented herein is also applicable to any wireless device that implements optical communication. For example, other exemplary devices 200 include, but are not limited to, hearing aids, fitness monitors, cellular phones, laptop computers, tablet computers, and the like.

The present invention may, of course, be carried out in other ways than those specifically set forth herein without departing from essential characteristics of the invention. The present embodiments are to be considered in all respects as illustrative and not restrictive, and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein.