Optical interferometric proximity sensor with optical path extender

Abstract

This disclosure provides an optical interferometric proximity sensor with an optical path extender. The optical proximity sensor includes an optical path extender that extends the optical path length of the optical proximity sensor without a corresponding extension of the geometric path length of the optical proximity sensor. The optical path extender may be a high-refractive-index material positioned along the optical path through the optical proximity sensor. The optical path extender may include one or more redirection features configured to change the direction of light traveling within the optical proximity sensor. The optical path extender may include a photonic component configured to simulate the extension of the geometric path within the optical proximity sensor by applying a momentum-dependent transfer function to the light passing through it.

Description

Technical Field

[0001] The embodiments described herein relate to optical sensors, and more specifically to optical interferometric proximity sensors configured to determine the distance to an object and / or the velocity of the object. Background Technology

[0002] Electronic devices may include systems or sensors—referred to herein as “proximity sensors”—for measuring or estimating the distance in free space between the electronic device and an object or surface (such as a user of the electronic device). However, conventional proximity sensors may require free space along optical paths to achieve satisfactory sensing performance, which can lead to an increase in the thickness of the proximity sensors and the equipment on which they are deployed. Summary of the Invention

[0003] The embodiments described herein relate to an optical proximity sensor including an optical path extender. The optical path extender can be positioned between a light source and an aperture in the housing of the optical proximity sensor. The light source is configured to illuminate an object and collect the reflected signal to determine the distance to the object and / or the velocity of the object based on a self-mixing interferometry method. The optical path extender can increase the optical path length of the optical proximity sensor, thereby allowing the optical proximity sensor to have a reduced thickness compared to conventional optical proximity sensors, while achieving similar or improved sensing performance. Attached Figure Description

[0004] Reference will now be made to the representative embodiments illustrated in the accompanying drawings. It should be understood that the following description is not intended to limit this disclosure to one of the included embodiments. Rather, the disclosure provided herein is intended to cover alternatives, modifications, and equivalents that may be included in the substance and scope of said embodiments and are defined by the appended claims.

[0005] Figure 1 A schematic diagram depicts an electronic device, such as the one described herein, that incorporates a proximity sensor to determine the distance to and / or the speed of an object near the electronic device.

[0006] Figure 2 An exemplary optical proximity sensor with an optical path extender integrated with a VCSEL light source is shown.

[0007] Figures 3A to 3B An exemplary optical proximity sensor is shown, which includes a redirection feature to increase the optical path length of the optical proximity sensor.

[0008] Figures 4A to 4B An exemplary optical proximity sensor is shown, which includes photonic components to increase the optical path length of the optical proximity sensor.

[0009] Figure 5AA schematic diagram depicts another electronic device, such as the one described herein, that incorporates a proximity sensor to determine the distance to and / or the speed of an object near the electronic device.

[0010] Figure 5B A schematic diagram of another electronic device, such as the one described herein, incorporates a proximity sensor to determine the distance to a movable surface of the electronic device and / or the speed of that movable surface.

[0011] Figure 6A A schematic diagram depicts an electronic device, such as the one described herein, that incorporates a proximity sensor to determine the distance and / or speed of a user's finger relative to an input area of ​​the electronic device.

[0012] Figure 6B A schematic diagram is depicted of an electronic device, such as the one described herein, which incorporates a proximity sensor to determine the distance and / or speed of a user's finger relative to the touch input area of ​​the electronic device.

[0013] Figure 6C A schematic diagram of an electronic device, such as that described herein, combines a proximity sensor to determine the distance to and / or the velocity of the movable surface of the electronic device to which a user of the electronic device can exert force.

[0014] Figure 6D Another schematic diagram depicts an electronic device, such as the one described herein, which incorporates a proximity sensor to determine the distance to and / or the velocity of the movable surface of the electronic device to which a user of the electronic device can exert force.

[0015] Figure 7 A flowchart illustrating an exemplary operation of a method of operating a proximity sensor, as described herein.

[0016] Figure 8 A sample electrical block diagram of an electronic device capable of performing the operations described herein is shown.

[0017] Use the same or similar reference numerals in different figures to indicate similar, related or identical items.

[0018] The use of crosshairs or shading in the accompanying drawings is generally provided to clarify the boundaries between adjacent elements and to improve the readability of the drawings. Therefore, the presence or absence of crosshairs or shading does not indicate or suggest any preference or requirement for a particular material, material properties, element proportions, element dimensions, commonalities of similar illustrated elements, or any other feature, property, or characteristic of any element shown in the accompanying drawings.

[0019] Similarly, some of the figures include vector, ray, trace, and / or other visual representations of one or more exemplary paths through one or more media that can be taken by one or more photons, which may include reflection, refraction, diffraction, etc., and the one or more photons originate from one or more light sources shown in the figures or omitted from the figures in some cases. It should be understood that these simplified visual representations of light are provided merely to facilitate understanding of the various embodiments described herein, and therefore need not be presented or shown to scale or with angular precision or accuracy, and therefore are not intended to indicate any preference or requirement for the illustrated embodiments to receive, emit, reflect, refract, focus, and / or diffract light at any particular shown angle, orientation, polarization, color, or direction, other than the other embodiments described or referenced herein.

[0020] Additionally, it should be understood that the proportions and dimensions (relative or absolute) of the various features and elements (as well as their sets and groups), and the boundaries, spacing, and positional relationships therebetween, are provided in the accompanying drawings solely to facilitate understanding of the various embodiments described herein, and may therefore be unnecessarily presented or shown for scaling and are not intended to indicate any preference or requirement for the illustrated embodiments to exclude embodiments in conjunction with them. Detailed Implementation

[0021] The embodiments described herein relate to optical proximity sensors for electronic devices. These embodiments typically include a vertical-cavity surface-emitting laser (“VCSEL”) radiating a beam toward an object near the optical proximity sensor to determine the distance to the object and / or the velocity of the object relative to the optical proximity sensor. The distance to the object and / or the velocity of the object can be determined based on the reflection of the radiated beam from the outer surface of the object. The object can be inside or outside the electronic device incorporating the optical proximity sensor. The beam can have a wavelength modulated according to a specific pattern, referred to herein as “wavelength modulation”.

[0022] Optical proximity sensors may include one or more optical path extenders to reduce the thickness of the optical proximity sensor by extending the optical path length. Therefore, optical proximity sensors can occupy less space in electronic devices, and / or can be placed in smaller, thinner devices compared to conventional optical proximity sensors.

[0023] Optical path extenders can extend the optical path length of an optical proximity sensor in any of a variety of ways. In some cases, the optical path extender can be a high-refractive-index material positioned along the optical path through the optical proximity sensor. In other cases, the optical path extender can be integrated with a VCSEL light source, for example, as a substrate for the VCSEL light source, as discussed above. Figure 2 To be discussed in more detail.

[0024] An optical path extender may include one or more redirection features configured to change the direction of light traveling between the VCSEL light source and the window, as described above. Figures 3A to 3B This will be discussed in more detail. Alternatively, the optical path extender may include a photonic component configured to simulate the extension of the geometric path within the optical proximity sensor by applying a momentum-dependent transfer function to the light traveling through it, as discussed in [reference to...]. Figures 4A to 4B To be discussed in more detail.

[0025] For simplicity, exemplary embodiments are understood to relate to VCSELs configured to emit light in a spectral range that includes non-visible bands (e.g., infrared or ultraviolet). However, it is understood that this is merely an example, and in other embodiments, more than one VCSEL (e.g., an array of VCSELs arranged in any suitable pattern) may be used, or alternatively, one or more VCSELs configured to emit light in a spectral range that includes the visible band may be used. Furthermore, while not all embodiments require this, the exemplary VCSELs described with reference to the numerous embodiments described below are understood to be Class 1 lasers operating in optoelectronic modules or systems as defined by the American National Standards Association; in other cases, higher power lasers may be used. Alternatively or alternatively, the embodiments described herein may include other lasers (e.g., edge-emitting lasers (EELs), vertical external cavity surface-emitting lasers (VECSELs), horizontal cavity surface-emitting lasers (HCSELs), quantum cascade lasers (QCLs), solid-state lasers, fiber lasers, etc.) and / or quasi-coherent and incoherent light sources (e.g., light-emitting diodes (LEDs), RC-LEDs, superluminescent diodes (SLDs), etc.).

[0026] As described above, a light beam emitted from the VCSEL of an optical proximity sensor can be reflected from an object. At least a portion of the reflected light can be guided back into the VCSEL to return (i.e., re-enter) the quantum well layer of the VCSEL, interfering with its operation and altering the electrical properties of the VCSEL. The changes in the electrical and / or optical properties of the VCSEL are related to (1) the distance from the optical proximity sensor to the surface of the object and (2) the wavelength of the light emitted by the VCSEL.

[0027] Understandably, because the wavelength of the light emitted by the VCSEL—whether modulated or fixed—is known, any measured interference (also known as a “self-mixing” effect) can be correlated with the relative displacement of the surface of the separated object and the optical proximity sensor, for example, by counting interference mode jumps or by the characteristics of quantitative beat frequencies (e.g., via frequency domain analysis). This relative displacement can further be correlated with the absolute distance between the surface of the separated object and the optical proximity sensor. This distance is referred to herein as the “measured distance” between the separated optical proximity sensor and the object surface. As can be understood, this configuration utilizes an effect commonly referred to as “self-mixing” interferometry or reflectance determination.

[0028] The following is for reference Figures 1 to 8 The foregoing embodiments and other embodiments will be discussed here. However, those skilled in the art will readily understand that the detailed descriptions given herein with respect to the accompanying drawings are for illustrative purposes only and should not be construed as limiting.

[0029] Figure 1 A schematic diagram 100 depicts an electronic device 102 configured to measure the distance d to an object 104 and / or the velocity v of the object 104 along the line-of-sight axis relative to an optical proximity sensor 110 disposed within a housing of the electronic device 102. The electronic device may include a power controller 122, a processing unit 124, and a memory 126. In some cases, the power controller 122, processing unit 124, and / or memory 126 are included as part of the optical proximity sensor 110. In other cases, the power controller 122, processing unit 124, and / or memory 126 are separate components of the electronic device 102.

[0030] The optical proximity sensor 110 may include one or more VCSEL light sources 112, a window 114, and one or more optical path extenders 116. Broadly speaking, the optical proximity sensor 110 can be used to determine the distance d and / or velocity v of an object 104. By extending the optical path length beyond the apparent optical thickness of the optical proximity sensor 110, the optical path extender 116 can reduce the thickness of the optical proximity sensor. Therefore, the optical proximity sensor 110 occupies less space in the electronic device 102, and / or the optical proximity sensor can be placed in a smaller, thinner device compared to conventional optical proximity sensors, while achieving similar or improved sensing performance. Relative to Figures 2 to 4B An exemplary optical path extender will be discussed in more detail.

[0031] A power controller 122 is coupled to the VCSEL light source 112. Each of these components, as well as other components of the optical proximity sensor 110 that may be required or preferred in a particular embodiment or implementation, may be wholly or partially housed within the component housing. The optical proximity sensor 110 also includes a window 114 configured to allow light emitted from the VCSEL light source 112 to pass through the component housing to illuminate the surface of the object 104. In the illustrated embodiment, the VCSEL light source 112 is aligned with the window 114 such that light emitted from the VCSEL light source 112 passes through the window 114 and illuminates the surface of the object 104 (which may be the inner surface of a user, electronic device, etc.).

[0032] In these examples, processing unit 124 may be configured to cause power controller 122 to generate a triangular current waveform (or other suitable periodic or non-periodic waveform) to inject current into VCSEL light source 112. For simplicity, the injection of current into VCSEL light source to emit light, whether by modulation or otherwise, and the facilitation of self-mixing operation, whether by a power controller or processing unit as described herein, are referred to herein as “driving” the light source.

[0033] Reflections from object 104 pass through window 114 and re-enter VCSEL light source 112 to induce self-mixing interference directly related to distance d. In some cases, power controller 122 may be further configured to monitor the power output from one or more photodiodes optically coupled to VCSEL light source 112 in order to quantify and / or otherwise determine the variation in power output of VCSEL light source 112 caused by self-mixing effects (see, for example, Equations 2 and 3 below).

[0034] The optical proximity sensor 110 may have a geometric path length l extending between the VCSEL light source 112 and the target 104. The optical proximity sensor 110 may have an associated optical path length (OPL), which is equal to the product of the geometric path length l and the refractive index of the optical proximity sensor 110. The refractive index may vary along the geometric path length l of the optical proximity sensor 110, in which case the optical path length can be expressed by Equation 1 as follows:

[0035] OPL=∫ C nds equation 1

[0036] Where n is the local refractive index as a function of the distance along the geometric path C.

[0037] The optical path length is proportional to the time (i.e., time of flight) it takes for light to travel along the geometric path of the optical proximity sensor 110. As described above, the optical path extender 116 can be extended by increasing the portion along the geometric path between the VCSEL light source 112 and the window 114. Figure 1 The optical path length of the optical proximity sensor 110 is extended by using the refractive index (indicated by l') without a corresponding extension of the geometric path length l.

[0038] The optical path extender 116 can extend the optical path length of the optical proximity sensor 110 in any of a variety of ways. In some cases, the optical path extender 116 can be a high-refractive-index material positioned between the VCSEL light source 112 and the window 114. In some cases, the optical path extender 116 can be integrated with the window 114. In some cases, the optical path extender 116 can be integrated with the VCSEL light source 112, for example, as a substrate for a bottom-emitting (flip-chip) VCSEL light source, as discussed above. Figure 2 To be discussed in more detail.

[0039] Optical path extender 116 may include one or more redirection features configured to change the direction of light traveling between VCSEL light source 112 and window 114 to create a folded path, as described above. Figures 3A to 3B This will be discussed in more detail. Alternatively, the optical path extender 116 may include a photonic component configured to simulate the extension of the geometric path within the optical proximity sensor by applying a momentum-dependent transfer function to the light traveling through it, as discussed in [reference to...]. Figure 4A as well as Figure 4B To be discussed in more detail.

[0040] As described above, the optical proximity sensor 110 can be used to determine the distance d to the object 104 and / or the velocity v of the object. For example, in one embodiment, the optical proximity sensor 110 can use wavelength modulation to simultaneously detect the distance d to the object 104 and the velocity v of the object relative to the optical proximity sensor 110. Wavelength modulation can be achieved by modulating the drive current supplied to the VCSEL light source 112.

[0041] An exemplary wavelength modulation utilizes a triangular waveform comprising an "upward cycle" (where current is supplied to the VCSEL light source 112, and correspondingly, the wavelength of the radiated beam emitted from it increases linearly at a specific rate) and a "downward cycle" (where current is supplied to the VCSEL light source 112, and the wavelength of the radiated beam emitted from it decreases linearly at the same specific rate). In this example, the wavelength fluctuations can effectively simulate the movement of object 104 toward and away from optical proximity sensor 110, regardless of whether object 104 is actually moving. In these examples, the frequency content of the power output from VCSEL light source 112—affected by self-mixing interference effects—can be described by Equation 2, presented below.

[0042] More specifically, in equation 2 (hereinafter), the parameter f t This indicates the frequency at which the power output of the VCSEL light source 112 from the optical proximity sensor 110 is modulated due to self-mixing at a specific time t during light emission at wavelength λ by the VCSEL light source 112 of the optical proximity sensor 110. Parameter f t It can represent the baseband frequency or intermediate frequency (IF), which is typically several orders of magnitude lower than the optical carrier frequency (wavelength) and its modulation, and is easily sampled by radio frequency electronics.

[0043] It is understandable that the absolute distance d to the object changes (which is equal to the total round-trip distance d). rt The light received by the VCSEL light source 112 at time t will have a different wavelength compared to the light emitted by the VCSEL light source 112 at the same time t, because the wavelength difference between the two beams is related to the following quantity: the rate of change of wavelength over time. Multiply by the round-trip distance d of the previously emitted light traveling from the VCSEL light source 112 to the object and back. rt Total round-trip flight time required.

[0044] In this way, the power output from the VCSEL light source 112 follows a triangular waveform (e.g., the current is expressed as...). The power output from the VCSEL light source 112 is injected at a rate that corresponds to the interference signal superimposed on the triangular waveform. In addition, the power output from the VCSEL light source 112 has an interference signal superimposed on the triangular waveform, which corresponds to the effect of constructive or destructive interference caused by light of different wavelengths interfering with each other in a specific way.

[0045] More specifically, superposition interference corresponds to the number of constructive and destructive interference "mode" transitions (e.g., also known as beat frequencies) that occur between two specific wavelengths of light, based on the absolute distance to the object (or more specifically, the round-trip time required to travel to and from the object) and the rate of change of wavelength. (which is based on the rate of change of current injected into the VCSEL light source 112) To determine.

[0046] In other words, the difference between the wavelength of light emitted from VCSEL source 112 at time t0 and the wavelength of light emitted from VCSEL source 112 at time t1 is expressed by the rate of change of wavelength. A definite quantity. In this way, because light of different wavelengths is emitted at different times (based on the rate of change). Based on the time of emission of a specific wavelength, light of different wavelengths is received in the VCSEL light source 112.

[0047] Thus, it can be generally and broadly understood that the frequency content of the power output from the VCSEL light source 112 (e.g., the parameter f) t This is directly related to the OPL of the separated VCSEL light source 112 and object 104.

[0048] Furthermore, it can be understood that the parameter f t One or more Doppler effects caused by the velocity v of object 104 can be increased or decreased. For example, if object 104 is moving toward the optical proximity sensor (e.g., parallel to the propagation direction of the emitted beam), then the frequency f t It can be increased. Alternatively, if object 104 is moving away from the optical proximity sensor (e.g., parallel to the propagation direction of the emitted beam), then the frequency f t It can be reduced.

[0049] Equation 2, regarding the values ​​mentioned above, is as follows:

[0050]

[0051] In a more general form, the direction of motion of object 104 can also be considered (or more specifically, the angle θ of motion of object 104 relative to the propagation direction of the emitted beam). Equation 3 represents this more general form as follows:

[0052]

[0053] Using equation 2 or equation 3, it can be understood that, by The distance to object 104 and the velocity v of object 104 can be readily determined by monitoring one or more characteristics of the frequency content of the power consumed by the VCSEL light source during the upward and downward cycles of the triangular modulation waveform. In a sawtooth modulation waveform, v can be derived from the time and / or spectral phase changes between successive cycles. As described with reference to some of the following embodiments, these measurements obtained from the VCSEL light source can be calibrated, adjusted, or otherwise modified in response to similar measurements obtained from an auxiliary VCSEL light source. It should be noted that f t Sampling can be performed at a specific sampling frequency or bandwidth fs. The result is f t In [0, f s Any value outside the domain will be collapsed or reflected back to [0, f]. s The domain will be adjusted accordingly in Equation 2.

[0054] The implementation scheme proposed in this paper, d in equation 3 rt A similar or thinner optical depth t can be increased, which leads to the measured f t Moving towards higher RF frequencies. In addition to a thinner device form factor, the movement of f...t Being away from dominant low-frequency background noise (e.g., low-frequency driver, laser and detector noise and / or nonlinear residuals) also enables higher detection signal-to-noise ratio, wider spatial sensing range and better spatial sensing accuracy.

[0055] In many implementations, the optical proximity sensor 110 is configured to utilize triangular waveform modulation to obtain both distance and velocity information from a VCSEL light source (or VCSEL array), but it is understood that this is merely an example and other construction and modulation techniques may be used.

[0056] VCSEL light source 112 may be a VCSEL light source formed on a substrate or semiconductor die; for the sake of simplicity, many of these components are omitted from the illustrated embodiments, which are described in more detail with reference to the other figures presented herein. In many cases, VCSEL light source 112 is housed within a protective housing, potting compound, or encapsulation (including any enclosure or housing of electronic device 102) to prevent damage.

[0057] The VCSEL light source 112 of the optical proximity sensor 110 can be formed as a pattern or array, although this may not be necessary. The VCSEL light source 112 of the optical proximity sensor 110 can be formed from any number of suitable materials or combinations of materials. In one exemplary embodiment, the VCSEL light source 112 of the optical proximity sensor 110 includes, but is not limited to, or expresses the following requirements: a first distributed Bragg reflector layer; an oxide layer defining an emission aperture; a multi-quantum well structure; a second distributed Bragg reflector layer; and so on. In other examples, additional or fewer layers may be required.

[0058] Any fixed or portable electronic device may incorporate an optical proximity sensor such as that described herein. Exemplary electronic devices include, but are not limited to: mobile phone devices; tablet devices; laptop devices; desktop computers; computing accessories; peripheral input devices; home or commercial networked devices; aircraft, marine, underwater, or land vehicle control or networking devices; mobile entertainment devices; augmented reality devices; virtual reality devices; industrial control devices; digital wallet devices; home or commercial security devices; wearable devices; head-mounted devices; handheld controllers; health or medical devices; implantable devices; devices embedded in clothing; fashion accessory devices; home or industrial appliances; media devices; and so on.

[0059] Similarly, the optical proximity sensor 110 can be used by an electronic device for a variety of suitable purposes. Exemplary purposes include, but are not limited to: detecting the distance and velocity of a user's finger (or other object, such as a stylus) to an input surface or component of the electronic device; detecting the distance and velocity of a user's body (or any other object) to an input surface or component of the electronic device; detecting deflection of the surface of the electronic device's housing due to deformation caused by force applied by the user or other object, such as a stylus; and so on.

[0060] Similarly, the optical proximity sensor 110 may include any number of suitable optical path extenders, lenses, or beamforming elements. Examples include, but are not limited to: reflectors; mirrors; translucent lens windows; transparent lens windows; concave lenses; convex lenses; tilting lenses; microlenses; macrolenses; collimators; polarizers; color filters; infrared cut-off filters; infrared bandpass filters; fiber optic cables; and so on.

[0061] In many embodiments, the optical proximity sensor 110 includes a component housing formed of a plastic or acrylic material; other conductive or non-conductive / thermal insulating materials, including glass and metal, may also be suitable. The component housing may be formed from a single material, or alternatively, it may be formed from multiple different material layers or regions joined together in a suitable manner (e.g., by adhesives, welding, etc.).

[0062] The housing of the optical proximity sensor 110 may be opaque or transparent, or may include both transparent and opaque areas. The housing may include one or more reflective areas or regions.

[0063] In many embodiments, the component housing includes a lens 114 or window disposed in or formed within a hole defined by the component housing. Typically, the lens or window is positioned directly above and aligned with the VCSEL light source 112. Due to this configuration, the light beam emitted / radiated from the VCSEL light source 112 can propagate outward from the component housing of the optical proximity sensor 110. As a further result of this configuration, one or more reflections of the emitted / radiated light beam that may be reflected from the surface of the object 104 can be received by the VCSEL light source 112.

[0064] In many embodiments, the optical proximity sensor 110 also includes one or more photodiodes disposed adjacent to or integrated within the VCSEL light source 112. In these examples, the optical proximity sensor 110 (or more specifically, circuitry or a processor communicatively coupled to the optical proximity sensor 110) can monitor the power output from the photodiodes to determine one or more performance characteristics, such as the beat frequency of the power output of the VCSEL light source 112 (see, for example, Equations 2 and 3). However, it is understood that the foregoing example is merely one example; power monitoring and / or measurement of the power output of the VCSEL light source and / or the power consumption of the VCSEL light source can be performed in a variety of suitable ways.

[0065] As with other embodiments described herein, the VCSEL light source 112 can be configured to emit a laser beam outward from the component housing of the optical proximity sensor 110. In the illustrated embodiment, the VCSEL light source 112 is oriented to emit / radiate light in a direction substantially perpendicular to the edge of the housing of the electronic device 102. However, it is understood that this is merely an example, and other emission or radiation directions are possible or even preferred (e.g., determining a target velocity outside the edge of the device housing).

[0066] As with other embodiments described herein, the VCSEL light source 112 is further configured to receive reflections of the emitted / radiated beam leaving the object 104. Such reflections can cause self-mixing interference within the VCSEL light source 112, which in turn can affect the power output of the VCSEL light source 112. Therefore, monitoring the power output of the VCSEL light source 112 (e.g., by monitoring the output of a photodiode, as described above) can be used to determine and / or calculate the distance d and velocity v of the object 104 along the optical axis of the emitted beam (see, for example, Equations 2 and 3).

[0067] The optical proximity sensor 110 and the electronic device 102 can be communicatively or functionally coupled in any suitable manner. More specifically, the optical proximity sensor 110 can be configured to transmit distance and / or speed information (which is calculated based on the self-mixing of the VCSEL light source 112 or otherwise determined) to the processor or system of the electronic device 102 in any suitable manner, according to any protocol conforming to any suitable digital or analog form or format.

[0068] Furthermore, as described above, electronic device 102 can be any suitable electronic device, including fixed and portable electronic devices. In one embodiment, electronic device 102 is a wearable electronic device, such as a smartwatch. In this example, electronic device 102 may utilize optical proximity sensor 110 to determine the distance to the user (represented by object 104) and the speed of the user when interacting with electronic device 102. For example, electronic device 102 may utilize signals transmitted from optical proximity sensor 110 to determine whether the user is wearing a smartwatch or is turning the smartwatch towards the user's face.

[0069] More specifically, in some embodiments, electronic device 102 may be configured to perform a function when it is determined that a user must cross one or more thresholds (such as distance thresholds or speed thresholds). Such thresholds may be variable or fixed and may be set by and / or stored in the memory of electronic device 102. In some examples, the thresholds may be based on user settings, application settings, or operating system settings or operating modes. In other cases, such thresholds may be at least partially based on a specific application executed by or executored by the processor of electronic device 102. For example, the set of thresholds associated with a telephone application may differ from the set of thresholds associated with a gaming application. It is understood that any suitable threshold or set of thresholds stored or accessed in any suitable form or format may be used to notify one or more actions of electronic device 102 in response to a signal received from optical proximity sensor 110.

[0070] In one specific implementation, electronic device 102 may disable the screen of electronic device 102 when it is determined that the user is far away from electronic device 102.

[0071] In another specific embodiment, electronic device 102 may modify the display or power settings of electronic device 102 based on the user's distance and speed. Examples include, but are not limited to: reducing the brightness of the display or display area when a signal is received from optical proximity sensor 110 that the user is covering the display; increasing the brightness of the display when a signal is received from optical proximity sensor 110 that the user is covering the display; highlighting user interface elements (e.g., list items, buttons, etc.) of the graphical user interface when a signal is received from optical proximity sensor 110 that the user has hovered their finger near the display; highlighting or otherwise modifying user interface elements of the graphical user interface when a signal is received from optical proximity sensor 110 that the user has hovered their finger near an input component (e.g., a rotary input device, a button input device, a touch input device, etc.) of electronic device 102; and so on.

[0072] In another embodiment, the electronic device 102 may utilize the interferometric measurement signal received from the optical proximity sensor 110 to monitor and / or authenticate the user's biometric information (e.g., user heart rate pattern, blood pressure, breathing, chewing, speaking, gestures, and movement). In another embodiment, the electronic device 102 may utilize the interferometric measurement signal received from the optical proximity sensor 110 to measure target characteristics, including but not limited to particles, particle count, surface texture, subsurface texture, etc.

[0073] In another embodiment, electronic device 102 may be a portable electronic device, such as a cellular phone. In these examples, electronic device 102 may utilize speed or distance signals received from optical proximity sensor 110 to determine the appropriate time to disable or enable the touch-sensitive display of electronic device 102 when the user of the electronic device raises the cellular phone to the user's ear.

[0074] In another embodiment, electronic device 102 may use speed or distance signals received from optical proximity sensor 110 to determine whether electronic device 102 is falling or about to hit a surface.

[0075] In another embodiment, electronic device 102 may be a vehicle accessory or attachment. In these examples, electronic device 102 may use speed or distance signals received from optical proximity sensor 110 to determine the distance to and / or speed of another vehicle, pedestrian, or road hazard.

[0076] In another embodiment, electronic device 102 may position an optical proximity sensor, such as optical proximity sensor 110, within an input / output communication port or power port of electronic device 102. In these examples, electronic device 102 may use speed or distance signals received from optical proximity sensor 110 to determine whether a cable is properly seated in the port, whether the cable is being moved too fast, or whether it is being removed in a manner that could damage electronic device 102, etc.

[0077] It is understood that the foregoing exemplary embodiments are not exhaustive, and that the optical proximity sensors described herein can be used by electronic devices in any suitable manner to determine the distance and / or velocity of a known or unknown object or surface relative to the electronic device.

[0078] For example, in some embodiments, the electronic device may include more than one optical proximity sensor, as described herein. In another example, the electronic device may include an array of optical proximity sensors arranged in a pattern, such as in a row.

[0079] In many cases, optical proximity sensors, as described herein, can be housed within the housing of an electronic device and aligned with a transparent aperture defined by the housing; however, this may not be necessary. For example, in some embodiments, the optical proximity sensor may be located behind a display. In other cases, the optical proximity sensor may be entirely housed within the housing of the electronic device. In these examples, the optical proximity sensor can be used to detect deflection or deformation in the surface of the electronic device, which may arise from a user intentionally applying force to that surface. For example, in one embodiment, the optical proximity sensor is entirely positioned within the housing of the electronic device, behind a display. In this example, when a user of the electronic device applies force to the display, the display may deform or bend, thereby reducing the distance between the display and the optical proximity sensor. The optical proximity sensor can then detect and measure this deflection, and the processor of the electronic device (and / or the processor of the optical proximity sensor) can correlate the deflection with the magnitude of the force input.

[0080] As described herein, the optical path extenders discussed can extend the optical path length of an optical proximity sensor in any of a variety of ways. In some cases, the optical path extender can be a high refractive index material. Figure 2 An exemplary optical proximity sensor 210 is shown, featuring an optical path extender 216 integrated with a VCSEL light source 212. The optical proximity sensor 210 may be similar to the optical proximity sensors discussed herein (e.g., optical proximity sensor 110) and may have similar structure and / or functionality, including the VCSEL light source 212, window 214, and housing 230. The optical proximity sensor 210 may include the optical path extender 216, which is configured to extend an optical path through the optical proximity sensor. The optical path extender 216 may be a substrate comprising a high refractive index material. Examples of suitable high refractive index materials include gallium arsenide, gallium nitride, glass, polymers, chemical coatings, etc.

[0081] In some cases, the optical path extender 216 can be the substrate of the VCSEL light source 212 or another component. Figure 2 In the illustrated embodiment, the VCSEL light source 212 is a flip-chip VCSEL, meaning that light is fired upwards through a substrate 232 on which the VCSEL chip is formed. The substrate 232 may be formed of a high-refractive-index material, such as gallium arsenide, such that the substrate 232 forms at least a portion of the optical path extender 216.

[0082] In many traditional flip-chip VCSELs, this substrate is thinned (e.g., to 0.4 mm, 0.1 mm, or less) after fabrication to reduce the chip thickness. Figure 2In this implementation, substrate 232 is designed to have minimal optical loss in thickness at VCSEL wavelengths, without becoming thinner or thinner than conventional VCSELs. This can be further extended by increasing the proportion of the geometric path of optical proximity sensor 210, in which light travels through the high-refractive-index material of optical path extender 216. In some cases, substrate 232 has a thickness t between 0.25 mm and 2 mm, between 0.4 mm and 1 mm, between 0.6 mm and 0.8 mm, etc. The refractive index of substrate 232 can be between 1.5 and 4.5, between 3 and 4, between 3.2 and 4.8, etc. Therefore, the optical path length can be between 2.5 times and 5 times the thickness of substrate 232, between 3 times and 4.5 times the thickness of substrate 232, etc.

[0083] As described above, the optical path extender discussed herein may include one or more redirection features configured to change the direction of light traveling along the optical path of an optical proximity sensor. Figure 3A and Figure 3B Exemplary optical proximity sensors 310a and 310b are shown, which include redirection features to increase the optical path length of the optical proximity sensor. Optical proximity sensors 310a and 310b may be similar to the optical proximity sensors discussed herein (e.g., optical proximity sensors 110 and 210) and may have similar structures and / or functions, including a VCSEL light source 312, a window 314, optical path extenders 316a and 316b, and a housing 330.

[0084] Turning Figure 3A The optical path extender 316a can define an optical path 334a that extends through the optical path extender. For example... Figure 3A As shown, the length of the optical path 334a can be significantly longer than the thickness t of the optical path extender 316a, thereby producing an optical path length greater than the thickness t through the optical path extender. As mentioned above, the optical path length can be between 2.5 and 5 times the thickness t, between 3 and 4.5 times the thickness t, etc.

[0085] As described above, the optical path extender 316a may include a redirection feature to change the direction of the optical path 334a once or multiple times as the optical path 334a extends through the optical path extender 316a. For example, in Figure 3AIn this configuration, the optical path 334a changes direction twice. The optical path extender 316a may include mirrors 340a, 340b or other suitable redirection features to change the direction of the optical path. The optical path extender 316a may include additional optical features, such as optical features 342a, 342b, to guide light into and out of the optical path extender 316a. Optical features 342a, 342b may include collimators, lenses, etc. In various embodiments, mirrors 340a, 340b do not need to be flat and / or parallel to each other, such as... Figure 3A As shown. This directional freedom allows for additional beam pointing and shaping capabilities beyond the functionality of an optical path extender.

[0086] The optical path 334a, passing through the optical path extender 316a, changes direction twice, but in various embodiments, the optical path can change direction any number of times. (Go to...) Figure 3B The optical path extender 316b can define an optical path 334b ​​passing through it. Similar to optical path 334a, the length of optical path 334b ​​can be significantly longer than the thickness t of optical path extender 316b, thereby producing an optical path length greater than the thickness t through the optical path extender. In some cases, the redirection of light through optical path extender 316b can occur due to total internal reflection (or near total internal reflection) from the surface of optical path extender 316b.

[0087] In some cases, optical path extenders 316a and 316b may additionally or alternatively include high-refractive-index materials, including glass, polymers, chemical coatings, etc., to further increase the optical path length through the optical path extender. The reorientation and optical characteristics of optical path extenders 316a and 316b can include any suitable optical path extender, lens, or bundle-forming element. Examples include, but are not limited to: reflectors; mirrors; translucent lens windows; transparent lens windows; concave lenses; convex lenses; tilting lenses; microlenses; macrolenses; collimators; polarizers; color filters; infrared cutoff filters; infrared bandpass filters; fiber optic cables; etc. Materials used in the optical path extenders described herein can be selected or designed to obtain high throughput, low diffusion or fogging, low dispersion, and / or other optical, mechanical, and / or chemical properties to facilitate interferometric sensing.

[0088] As described above, the optical path extender discussed herein may include photonic components configured to simulate the extension of a geometric path within an optical proximity sensor. Figure 4A and Figure 4BExemplary optical proximity sensors 410a and 410b are shown, which include photonic components 416a and 416b to increase the optical path length of the optical proximity sensor. Optical proximity sensors 410a and 410b may be similar to the optical proximity sensors discussed herein (e.g., optical proximity sensors 110, 210, 310a, and 310b) and may have similar structures and / or functions, including a VCSEL light source 412, a window 414, and a housing 430.

[0089] Photonic components 416a and 416b can be positioned between the VCSEL light source 412 and the window 414, and can be configured to apply a transfer function to light passing through the photonic components to effectively propagate light a length much longer than the thickness of the photonic components. In some cases, each photonic component 416a and 416b applies a momentum-dependent transfer function to the light passing through it. Photonic components 416a and 416b can reproduce a Fourier transfer function, which describes the propagation of light through a different medium having an optical path length longer than the thickness of the photonic components. Photonic components 416a and 416b can maintain the propagation angle of light such that light rays exiting photonic components 416a and 416b are parallel to their corresponding incident rays.

[0090] In various implementation schemes, photonic components 416a and 416b can be implemented in a variety of ways. In some cases, such as Figure 4A As shown, photonic component 416a can be a planar parallel plate with a refractive index less than or equal to that of the background medium. In some cases, photonic component 416a comprises a uniaxial photonic crystal plate, such as a calcite crystal, with its axis oriented perpendicular to its inlet and outlet faces. In some cases, such as Figure 4B As shown, photonic component 416b is a metamaterial comprising multiple layers with different thicknesses. The metamaterial may include alternating layers formed of silicon and silicon dioxide.

[0091] The foregoing examples are not exhaustive; it will be understood that, generally and broadly, electronic devices can utilize one or more optical proximity sensors, as described herein, for any suitable purpose or function. For example, Figure 5A A schematic diagram 500a depicts an electronic device 502 configured to measure the distance d to an object 504 and / or the velocity of the object 504 relative to an optical proximity sensor 510 as described herein. In this exemplary embodiment, the optical proximity sensor 510 may include a beamforming lens that redirects light emitted from the optical proximity sensor 510 to an angle θ. In this manner and due to this configuration, the electronic device 502 and the optical proximity sensor 510 can determine velocities (e.g., v) in multiple directions or along multiple axes. x and v yIn this way, (optionally) together with one or more additional optical proximity sensors, the electronic device 502 can determine multi-axis speed and distance.

[0092] Other implementation schemes can be achieved in other ways. For example, Figure 5B A schematic diagram 500b depicts an electronic device 502 configured to measure the distance d to a flexible surface 508 and the velocity v of one or more deformations or bending of the flexible surface 508 using an optical proximity sensor 510. In this way, and due to this configuration, the bending of the flexible surface 508 can be quantified by the electronic device 502.

[0093] Expanding on these and related examples, presenting Figures 6A to 6D Various example use cases of optical proximity sensors are illustrated in this article. These figures depict wearable electronic devices, such as smartwatches, but it is understood that this is merely an example. As discussed in this article, optical proximity sensors can be incorporated into any suitable electronic device and used for any suitable purpose.

[0094] For example, Figure 6A A wearable electronic device 600, including a housing 602, is depicted that can be worn by a user (e.g., via a wristband 604). In this example, an optical proximity sensor 606 may be included within the housing 602 and positioned relative to a peripheral or bezel area of ​​a display 608 that defines a graphical user interface 608a with which the user can interact. Due to this configuration, the optical proximity sensor 606 may be configured and oriented to detect, measure, or otherwise determine the distance d and / or velocity v of the user's finger 610 relative to an input component 612. The input component 612 may be any suitable input component, including but not limited to: a rotary input component (e.g., a crown); a button input component; a solid-state input component; and so on.

[0095] In this exemplary embodiment, the wearable electronic device 600 may be configured to perform a first function when it is determined that a user's finger 610 is approaching the input component 612, a second function when it is determined that the user's finger 610 is leaving or moving away from the input component 612, a third function when it is determined that the user's finger 610 is hovering near or above the input component 612, and so on. It is understood that these examples are not exhaustive and the wearable electronic device 600 may perform any suitable function or operation based on the distance d and / or velocity v of the user's finger 610 relative to the input component 612, as determined by an optical proximity sensor.

[0096] For example, in one embodiment, wearable electronic device 600 may modify the position, characteristics, size, color or other properties of graphical user interface element 608b in response to changes in the distance d between input component 612 and user's finger 610.

[0097] In another example, Figure 6B A wearable electronic device 600, including a housing 602, is depicted and configured to be coupled to a user via a wristband 604. As described herein, an optical proximity sensor 606 may be disposed behind a display 608 that presents a graphical user interface 608a. In one example, the optical proximity sensor 606 is configured to emit light through an interpixel region of the display 608.

[0098] In this example, the optical proximity sensor 606 may be configured and oriented to detect, measure, or otherwise determine the distance d and / or velocity v of a user's finger 610 relative to the display 608 and / or the graphical user interface 608a. The display 608 may be implemented as or have, but is not limited to: a touch-sensitive screen or display; a force-sensitive screen or display; a tactile output surface; etc.

[0099] In this exemplary embodiment, as with other embodiments described herein, the wearable electronic device 600 may be configured to perform any suitable function or operation based on the distance d and / or velocity v (and / or the change therein over time) of the user’s finger 610 relative to the display 608, as determined by an optical proximity sensor.

[0100] In another example, Figure 6C A wearable electronic device 600, including a housing 602, is depicted and can be attached to a user via a wristband 604. As described herein, an optical proximity sensor may be disposed within the housing 602. In this example, the optical proximity sensor may be configured and oriented to detect, measure, or otherwise determine the distance d and / or velocity d of deflection of the display 608 caused by a downward force applied by the user's finger 610 to a graphical user interface 608a presented by the display 608. The display 608 may be positioned relative to a reference... Figure 6B The same configuration method is used, and this description will not be repeated.

[0101] In this exemplary embodiment, as with other embodiments described herein, the wearable electronic device 600 can be configured to perform any suitable function or operation based on the distance d and / or velocity v (and / or its change over time) of a user's finger 610 relative to the display 608, as determined by an optical proximity sensor. In many examples, the wearable electronic device 600 can be configured to correlate or otherwise convert at least one of the flexure distance d and / or velocity v of the display 608 into a magnitude F of force input.

[0102] In yet another example, Figure 6D A wearable electronic device 600, comprising a housing 602, is depicted and can be attached to a user via a wristband 604. As described herein, an optical proximity sensor 606 may be disposed within the housing 602, adjacent to the sidewall of the housing 602. More specifically, in this example, the optical proximity sensor 606 may be configured and oriented to detect, measure, or otherwise determine the distance d and / or velocity v of deflection of the housing sidewall or housing portion caused by a force F applied by the user.

[0103] In this exemplary embodiment, as with other embodiments described herein, the wearable electronic device 600 may be configured to perform any suitable function or operation based on a determined value (and / or the change therein) of the force F applied by the user's finger 610, as determined by an optical proximity sensor.

[0104] Figures 1 to 6B The foregoing embodiments, as well as their various alternatives and variations, described herein are generally presented for illustrative purposes and to facilitate understanding of the various possible constructions of optical proximity sensors such as those described herein. However, it will be apparent to those skilled in the art that some of the specific details presented herein may not be necessary for practicing particular embodiments or their equivalents.

[0105] Figure 7 A flowchart is provided to illustrate exemplary operation of a method 700 for operating a proximity sensor, as described herein. Method 700 includes operation 702, in which the frequency content of an output signal (e.g., a photodiode optically coupled to a VCSEL as described herein) is monitored. Next, at operation 704, distance and / or speed information can be determined based on the frequency content monitored in operation 702.

[0106] Figure 8 A sample electrical block diagram of an electronic device 800 capable of performing the operations described herein is shown. In some cases, the electronic device 800 may adopt a reference... Figures 1 to 7 Any form of electronic device described includes electronic devices 102, 502, and 602 and / or optical proximity sensors 110, 210, 310, 410, 510, and 610. Electronic device 800 may include one or more of a display 812, a processing unit 802, a power supply 814, a memory 804 or storage device, an input device 806, and an output device 810. In some cases, various specific embodiments of electronic device 800 may lack some or all of these components and / or include additional or alternative components.

[0107] The processing unit 802 can control some or all of the operations of the electronic device 800. The processing unit 802 can communicate directly or indirectly with some or all of the components of the electronic device 800. For example, a system bus or other communication mechanism 816 can provide communication between the processing unit 802, the power supply 814, the memory 804, the input device 806, and the output device 810.

[0108] Processing unit 802 can be implemented as any electronic device capable of processing, receiving, or transmitting data or instructions. For example, processing unit 802 can be a microprocessor, central processing unit (CPU), application-specific integrated circuit (ASIC), digital signal processor (DSP), or a combination of such devices. As described herein, the term "processing unit" is intended to cover one or more computing elements, such as a single processor or processing unit, multiple processors, multiple processing units, or other suitable configurations.

[0109] It should be noted that components of electronic device 800 may be controlled by multiple processing units. For example, selection components of electronic device 800 (e.g., input device 806) may be controlled by a first processing unit, and other components of electronic device 800 (e.g., display 812) may be controlled by a second processing unit, wherein the first processing unit and the second processing unit may or may not communicate with each other.

[0110] The power source 814 can be implemented using any device capable of providing power to the electronic device 800. For example, the power source 814 can be one or more batteries or rechargeable batteries. Additionally or alternatively, the power source 814 can be a power connector or power cord that connects the electronic device 800 to another power source, such as a wall power outlet.

[0111] Memory 804 can store electronic data that can be used by electronic device 800. For example, memory 804 can store electronic data or content such as, for example, audio and video files, documents and applications, device settings and user preferences, timing signals, control signals, and data structures or databases. Memory 804 can be configured as any type of memory. By way of example only, memory 804 can be implemented as random access memory, read-only memory, flash memory, removable memory, other types of storage elements, or combinations of such devices.

[0112] In various embodiments, display 812 provides graphical output, for example, associated with the operating system, user interface, and / or applications (e.g., chat user interface, issue tracking user interface, issue discovery user interface, etc.) of electronic device 800. In one embodiment, display 812 includes one or more sensors and is configured as a touch-sensitive display (e.g., single-touch, multi-touch) and / or force-sensitive display to receive input from a user. For example, display 812 may be integrated with a touch sensor (e.g., a capacitive touch sensor) and / or a force sensor to provide a touch-sensitive display and / or force-sensitive display. Display 812 is operatively coupled to processing unit 802 of electronic device 800.

[0113] The display 812 can be implemented using any suitable technology, including but not limited to liquid crystal display (LCD) technology, light-emitting diode (LED) technology, organic light-emitting display (OLED) technology, organic electroluminescent (OEL) technology, or another type of display technology. In some cases, the display 812 is positioned under a cover that forms at least a portion of the housing of the electronic device 800 and is visible through the cover.

[0114] In various embodiments, input device 806 may include any suitable component for detecting input. Examples of input device 806 include light sensors, temperature sensors, audio sensors (e.g., microphones), optical or visual sensors (e.g., cameras, visible light sensors, or invisible light sensors), proximity sensors, touch sensors, force sensors, mechanical devices (e.g., crowns, switches, buttons, or keys), vibration sensors, orientation sensors, motion sensors (e.g., accelerometers or velocity sensors), position sensors (e.g., Global Positioning System (GPS) devices), thermal sensors, communication devices (e.g., wired or wireless communication devices), resistance sensors, magnetic sensors, electroactive polymers (EAPs), strain gauges, electrodes, etc., or some combination thereof. Each input device 806 may be configured to detect one or more specific types of input and provide a signal (e.g., an input signal) corresponding to the detected input. For example, this signal may be provided to processing unit 802.

[0115] As discussed above, in some cases, input device 806 includes a touch sensor (e.g., a capacitive touch sensor) integrated with display 812 to provide a touch-sensitive display. Similarly, in some cases, input device 806 includes a force sensor (e.g., a capacitive force sensor) integrated with display 812 to provide a force-sensitive display.

[0116] Output device 810 may include any suitable component for providing output. Examples of output device 810 include light emitters, audio output devices (e.g., speakers), visual output devices (e.g., lamps or displays), haptic output devices (e.g., tactile output devices), communication devices (e.g., wired or wireless communication devices), and some combination thereof. Each output device 810 may be configured to receive one or more signals (e.g., output signals provided by processing unit 802) and provide an output corresponding to those signals.

[0117] In some cases, input device 806 and output device 810 are implemented together as a single device. For example, the input / output device or port may transmit electrical signals via communication networks such as wireless and / or wired network connections. Examples of wireless and wired network connections include, but are not limited to, cellular networks, Wi-Fi, Bluetooth, IR, and Ethernet connections.

[0118] Processing unit 802 may be operatively coupled to input device 806 and output device 810. Processing unit 802 may be adapted to exchange signals with input device 806 and output device 810. For example, processing unit 802 may receive an input signal from input device 806 corresponding to an input detected by input device 806. Processing unit 802 may decode the received input signal to determine whether to provide and / or modify one or more outputs in response to the input signal. Processing unit 802 may then send an output signal to one or more output devices in output device 810 to provide and / or modify the output as needed.

[0119] As used herein, the phrase "at least one of" following a series of items separated by the terms "and" or "or" modifies the list as a whole, not each member of the list. The phrase "at least one of" does not require selection of at least one of each of the listed items; rather, it allows for the inclusion of at least one of any item in the list and / or at least one of any combination of items and / or at least one of each item in the list. For example, the phrases "at least one of A, B, and C" or "at least one of A, B, or C" each refer to only A, only B, or only C; any combination of A, B, and C; and / or one or more of each of A, B, and C. Similarly, it is to be understood that the order of elements presented with respect to the combined or separate lists provided herein should not be construed as limiting this disclosure to the order provided.

[0120] It is understood that, although many implementations have been disclosed above, the operations and steps provided with respect to the methods and techniques described herein are intended to be exemplary and are therefore not exhaustive. It is further understood that alternative sequences of steps or fewer or additional operations may be required or desired for a particular implementation.

[0121] Although the foregoing disclosure has been described with reference to various exemplary embodiments and specific implementations, it should be understood that the various features, aspects, and functions described in one or more individual embodiments are not limited to applying them to the specific embodiments in which they are described, but rather they may be applied individually or in various combinations to one or more embodiments of the invention, regardless of whether such embodiments are described and whether such features are presented as part of said embodiments. Therefore, the breadth and scope of the invention should not be limited by any of the foregoing exemplary embodiments, but rather by the claims provided herein.

Claims

1. An electronic device, the electronic device comprising: The outer casing defines an opening; A self-mixing proximity sensor, at least partially located within the housing, comprising: A flip-chip vertical-cavity surface-emitting laser (VCSEL) source, wherein the flip-chip VCSEL source is formed on a gallium arsenide substrate and configured to emit a beam through the substrate and the aperture; and An optical path extender integrated with a VCSEL, the optical path extender being defined by the gallium arsenide substrate and having a thickness extending between the flip-chip VCSEL light source and the aperture, the optical path extender having an optical path length at least three times the thickness; and A processing unit, located within the housing and operatively coupled to the self-mixing proximity sensor, is configured to determine the distance to a target using the output signal of the self-mixing proximity sensor.

2. The electronic device according to claim 1, wherein: The self-mixing proximity sensor also includes: A lens, positioned in the aperture and configured to direct the light beam toward the target; and A power controller configured to monitor the power output of the flip-chip VCSEL light source to achieve a self-mixing interference effect; and The optical path extender is positioned between the flip-chip VCSEL light source and the lens.

3. The electronic device according to claim 1, wherein: The optical path length is between 3.5 mm and 4.5 mm; and The thickness of the optical path extender is between 0.8 mm and 1.5 mm.

4. The electronic device according to claim 1, wherein: The substrate has a thickness between 0.4 mm and 1 mm; and The substrate has a refractive index between 3 and 4.

5. The electronic device of claim 1, wherein the optical path extender includes one or more redirection features configured to change the direction of the light beam as it passes through the optical path extender.

6. The electronic device of claim 1, wherein the optical path extender includes a photonic component configured to apply a momentum-dependent transfer function to the light beam.

7. An optical proximity sensor for an electronic device, comprising: case; A vertical cavity surface-emitting laser (VCSEL) source, the VCSEL source being positioned within the housing and configured to emit a coherent beam toward an object; A photodiode, optically coupled to the VCSEL light source; An optical path extender, positioned between the VCSEL light source and the object, the optical path extender comprising a metamaterial having alternating layers of silicon and silicon dioxide; as well as A power controller, configured to: Monitor the power output of the photodiode; as well as The distance, velocity, or acceleration of the object reflecting the coherent light beam is determined, at least in part, based on the power output of the photodiode.

8. The optical proximity sensor of claim 7, wherein the power controller is configured to determine the characteristics of the inner surface of the housing.

9. The optical proximity sensor according to claim 7, wherein: The housing defines a hole; and The VCSEL light source is aligned with the aperture, so that the coherent beam passes through the aperture.

10. The optical proximity sensor according to claim 9, wherein the optical proximity sensor further comprises a lens disposed within the aperture.

11. The optical proximity sensor of claim 7, wherein the power controller is configured to drive the VCSEL light source with a triangular current waveform.

12. An electronic watch, comprising: The outer casing defines an opening; A display, which is at least partially located within the housing and configured to provide graphics output; A rotary input component, the rotary input component being configured to receive rotary input; as well as An optical proximity sensor, at least partially located within the housing, the optical proximity sensor comprising: A vertical-cavity surface-emitting laser (VCSEL) source, the VCSEL source being configured to emit a beam through the aperture; and An optical path extender, positioned within the optical path of the VCSEL light source, comprising a metamaterial having alternating layers of silicon and silicon dioxide; and A processing unit, located within the housing and operatively coupled to the optical proximity sensor, is configured to modify the graphic output based on the output signal of the optical proximity sensor.

13. The electronic watch of claim 12, wherein the optical path extender comprises a substrate having a refractive index between 3 and 4.

14. The electronic watch of claim 12, wherein the processing unit is configured to: Using the output signal of the optical proximity sensor, the change in distance between the object and the rotary input component is determined; and The graphical output is modified based on the change in the distance.

15. The electronic watch according to claim 12, wherein: The display is a touch-sensitive screen; and The optical proximity sensor is configured to emit the light beam through the touch-sensitive screen.

16. The electronic watch of claim 15, wherein the processing unit is configured to: Using the output signal of the optical proximity sensor, the position of the object relative to the touch-sensitive screen is determined; and The graphic output is modified based on the position of the object.

17. The electronic watch of claim 15, wherein the processing unit is configured to: Using the output signal of the optical proximity sensor, the force applied to the touch-sensitive screen is determined; and The graphic output is modified based on the force.

Images