Optical component with interlock feature

Abstract

The present disclosure relates to an optical component (200a-200h), the optical component (200a-200h) including: an optical substrate (202) configured to be transparent for light in a predefined wavelength range; an optical element (204) coupled with the optical substrate (202), wherein the optical element (204) is configured to implement a predefined optical function; an aperture element (206) configured to define an opening for the optical element (204) to, during an operation of the optical component (200a-200h), partially block light and partially allow light to pass through the opening; and an electrically conductive trace (208) configured to allow detection of a damaged condition of the optical component (200a-200h) by a variation of an electrical parameter of the electrically conductive trace (208), wherein the aperture element (206) and the electrically conductive trace (208) are disposed at the same side of the optical substrate (202).

Description

OPTICAL COMPONENT WITH INTERLOCK FEATURETechnical Field

[0001] The present disclosure relates generally to an optical component for use in an optoelectronic device, to an optoelectronic device including the optical component, and to methods thereof (e.g., a method of fabricating an optical component).Background

[0002] In general, optoelectronic devices are devices capable of converting electrical energy into light, or vice versa, thus providing light emission functionalities and / or light detection functionalities. Common examples of optoelectronic devices may include light projectors and flood illuminators for light emission, photo diodes for light detection, and / or solar cells for converting solar light into electrical energy. Optoelectronic devices may therefore be used in a variety of application scenarios, both in industrial- as well as in home-settings. Application examples of optoelectronic devices may include telecommunications (e.g., fiber optic communications), three-dimensional sensing, medical instruments, optical memories, optical control systems, and / or the like. Improvements in optoelectronic devices may thus be of particular relevance for the further advancement of several technologies.Brief Description of the Drawings

[0003] In the drawings, like reference characters generally refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the invention. In the following description, various aspects of the invention are described with reference to the following drawings, in which:FIG.1A shows a light-based sensing device in a schematic view, according to various aspects;FIG. IB shows an optoelectronic device in a schematic representation, according to various aspects;FIG.2A to FIG.2H show an optical component in a schematic representation, according to various aspects;FIG.3 A to FIG.3C show an optical component in a schematic representation, according to various aspects; andFIG.4 shows a schematic flow diagram of a method of fabricating an optical component, according to various aspects.Description

[0004] The following detailed description refers to the accompanying drawings that show, by way of illustration, specific details and aspects in which the invention may be practiced. These aspects are described in sufficient detail to enable those skilled in the art to practice the invention. Other aspects may be utilized and structural, logical, and electrical changes may be made without departing from the scope of the invention. The various aspects are not necessarily mutually exclusive, as some aspects may be combined with one or more other aspects to form new aspects. Various aspects are described in connection with methods and various aspects are described in connection with devices (e.g., an optical component, an optoelectronic device). However, it is understood that aspects described in connection with methods may similarly apply to the devices, and vice versa.

[0005] Optoelectronics is at the intersection between optics and electronics, and deals with devices capable of emitting, detecting, and / or otherwise controlling light. Optoelectronic devices are used in a wide range of application areas. For example, in the current market, there is a growing trend towards three-dimensional (3D) sensing, for example for face authentication, movement-tracking, eye-tracking, and the like. For this type of application, optoelectronic illuminators may flood the targets with light, or optoelectronic projectors may project light dots onto the targets, and the light impinging onto the targets is imaged and measured.

[0006] In general, there are several desirable properties for an optoelectronic device. As an example, there is a constant trend towards miniaturization, aimed at minimizing the overall size of an optoelectronic module. As a further example of particular importance for customer application, an optoelectronic device may be designed to ensure eye safety for a user. Eye safety in an optoelectronic device may be related to the properties of an optical path along which the light propagates. In particular, eye safety in an optoelectronic device may be related to the presence of damages (e.g., cracks, or a detaching) in an optical component of the optoelectronic device, e.g. an optical component to direct emitted light towards the field of illumination. The optical component may include, for example, a microlens array, a diffractive optical element, and / or the like. Illustratively, the presence of defects along the optical path may cause emitting light in undesired directions, and / or may cause emitting light having excessive power, thus leading to potential risks for a user.

[0007] An eye-safety feature in an optoelectronic device may be provided, for example, by a physical optical aperture that prevents optical radiation emitted outside the area of the optical component to flow out of the device. The optical aperture may illustratively serve as an optical baffle. As a further example, an optoelectronic device may include an eye-safety feature that has an electrical connection to the rest of the package, e.g. a so-called interlock feature. For example, an illuminator or a dot projector may include an interlock for triggering an eye-safety mechanism at the host system to prevent any eye-damage.

[0008] An interlock feature may be realized, for example, as a photo diode configured to detect part of the emitted light, thus enabling a detection of variations in the emitted light to trigger an interruption of the light emission in case the intensity of the emitted light increases above a predefined threshold. As a further example, which provides a simpler, yet efficient approach, an interlock feature may be realized as an electrically conductive trace coupled with the optical component. A damage in the optical component, such as a crack, or a detaching of the optical component (e.g., from the housing of the device) may cause a variation in an electrical parameter (e.g., a resistance) of the electrically conductive trace. Monitoring the electrical parameter of the electrically conductive trace may thus allow detecting possible damages and triggering an eye-safety mechanism.

[0009] An optical component for an optoelectronic device may thus include an optical element (e.g., a microlens array), a physical aperture disposed to at least partially overlap the optical element, and an electrically conductive trace that works as an interlock feature to monitor the presence of damages in the optical component. In a conventional configuration, the optical aperture and the electrically conductive trace are disposed on opposite sides of an optical substrate supporting the optical element, illustratively a substrate on which the optical element is formed or disposed. Usually, the optical aperture is disposed optically downstream of the electrically conductive trace considering an emission direction of light, and also optically downstream of the optical substrate (illustratively, on an “external side” of the substrate). This arrangement of the optical aperture is well-established because it allows a simple fabrication process (illustratively, the aperture may be deposited on the substrate after fabrication of the other parts of the component), and reduces the risk of wafer warpage or short circuits. However, such an arrangement of the optical aperture presents some drawbacks for the operation of a corresponding optoelectronic device, such as beam clipping of the emitted light with a consequent transmission loss. Illustratively, beam expansion may occur in the optical substrate (e.g., in glass), and the optical aperture at the exit side may cause a clipping of the light.

[0010] The present disclosure is based on the realization that disposing the optical aperture optically upstream of the optical substrate may minimize or avoid beam clipping, thus reducing transmission losses in the optical component. Illustratively, the optical aperture may be disposed with respect to the optical substrate such that, during operation of the optical component, light impinges first on the optical aperture and subsequently on the optical substrate. In some aspects, the optical aperture may be disposed in an “internal side” of the optical substrate, so that light passes through the aperture before the light arrives on the substrate and gets expanded within the substrate. This configuration may ensure that beam expansion occurring in the optical substrate does not lead to excessive beam clipping at the optical aperture.

[0011] As a further aspect, the present disclosure is based on the realization that disposing the optical aperture and the electrically conductive trace at the same side of the optical substrate (e.g., between the optical substrate and a microlens array) may provide a configuration in which the spatial limitation to the propagation of light provided by the aperture is supplemented by the profile of the trace. Illustratively, the trace may itself act as an additional aperture, thus providing an enhancement of the eye safety of the optical component. In addition, in some aspects, the electrically conductive trace and the optical aperture may be formed co-planar with one another (and, in some aspects, may include or may be made of the same material), thus allowing a simpler fabrication process and lower fabrication costs.

[0012] According to various aspects, an optical component for use in an optoelectronic device may be provided, the optical component including: an optical substrate (e.g., an optical wafer); a microlens array coupled with the optical substrate, e.g. disposed or formed on the optical substrate; and an aperture element configured to define an opening for the microlens array to, during an operation of the optical component, partially block light and partially allow light to pass through the opening (and, accordingly, through the microlens array), wherein the aperture element is disposed between the optical substrate and the microlens array.

[0013] According to various aspects, an optical component for use in an optoelectronic device may be provided, the optical component including: an optical substrate (e.g., an optical wafer); an optical element coupled with the optical substrate (e.g., disposed or formed on the optical substrate), wherein the optical element is configured to allow transmission of light in a predefined wavelength range (e.g., the optical element may be configured to implement an optical function, e.g. a lens function); an aperture element configured to define an opening for the optical element to, during an operation of the optical component, partially block light and partially allow light to pass through the opening; and an electrically conductive trace configuredto allow presence detection and detection of a damaged condition of the optical component by a variation of an electrical parameter of the electrically conductive trace, wherein the aperture element and the electrically conductive trace are disposed at the same side of the optical substrate.

[0014] According to various aspects, a method of fabricating an optical component may be provided, the method including: providing an optical substrate (e.g., an optical wafer); forming an aperture element and an electrically conductive trace at the same side of the substrate, wherein the aperture element is configured to define an opening for the optical element to, during an operation of the optical component, partially block light and partially allow light to pass through the opening, wherein the electrically conductive trace is configured to allow detection of a damaged condition of the optical component by a variation of an electrical parameter of the electrically conductive trace; and coupling an optical element with the substrate (e.g., disposing or forming the optical element on the optical substrate), wherein the optical element is configured to allow transmission of light in a predefined wavelength range (e.g., the optical element may be configured to implement an optical function, e.g. a lens function).

[0015] According to the configuration described herein, the optical aperture is disposed with respect to the optical substrate such that, in operation, the light passes through the opening defined by the aperture before propagating in the optical substrate. This disposition of the optical aperture may reduce or prevent beam clipping effects. Furthermore, in some aspects, the optical aperture may be disposed at the same side of the optical substrate as the interlock feature defined by the electrically conductive trace, so as to exploit the interlock feature for enhancing the confinement of the light, and to allow for a simpler fabrication process. The configuration proposed herein thus enables an improved transmission of light through the optical component (e.g., with reduced clipping) while ensuring eye-safety compliance.

[0016] Compared to a conventional arrangement, the configuration described herein may include an optical aperture disposed at the so-called “B-side” of the optical substrate, illustratively the side facing away from the field of illumination in case of an optical component used in a light-emitting optoelectronic device. Such disposition of the optical aperture provides confining the region in which light may travel prior to the occurrence of beam expansion in the optical substrate.

[0017] According to various aspects, the optical component described herein may be part of an optoelectronic device. In a preferred configuration, an optoelectronic device configured for light emission may include the optical component. In this scenario, the optical aperture (and insome aspects the electrically conductive trace) may be disposed at the side of the optical substrate that in operation faces the light source. In this configuration, the light emitted by the light source passes through the opening defined by the aperture and subsequently propagates through the optical substrate, thus reducing or preventing beam clipping when the light exits the substrate. The electrically conductive trace allows monitoring the integrity of the optical component, thus allowing to trigger an eye-safety mechanism (e.g., an interruption of the light emission, a decrease in the power of the emitted light, and / or the like) in a reliable and precise manner. Exemplary optoelectronic devices, in which the optical component may be integrated, may include world- and front-facing illuminators for 3D sensing (e.g., time-of-flight, pattern, stereo), and / or for augmented reality (gaming, industrial, educational, driver monitoring, etc.).

[0018] It is however understood that, in general, the optical component described herein may also be part of an optoelectronic device configured for light collection (e.g., a solar cell) and / or light detection (e.g., an optoelectronic device including a photo diode). In this scenario, the optical aperture may be disposed at the side of the optical substrate that in operation faces the field of view of the optoelectronic device. The electrically conductive trace allows monitoring the presence of damages in the optical element also in this scenario, thus prompting maintenance or replacement of the damaged portions, and ensuring a smooth and reliable operation of the optoelectronic device.

[0019] The optoelectronic device including the optical component may be integrated in a host device that exploits the optoelectronic device to implement one or more functionalities (e.g., telecommunications, distance measurements, object tracking, and the like). Exemplary host devices for the optoelectronic device may include a mobile communication device (e.g., a smartphone, a tablet, a laptop), a vehicle (e.g., a car), an automated machine (e.g., a drone, a robot), and the like.

[0020] In the present disclosure the term “optical element” is used to describe an element that is part of an optical component and that is configured to implement a predefined optical function, e.g. in a passive manner (illustratively, without being driven, for example via a current). An optical element may thus be configured to manipulate light passing through the optical element according to the corresponding optical function for which the optical element is designed. An optical element may illustratively be an optical surface configured (e.g., shaped) to define a predefined manipulation of the light. For example an optical element (or surface) may be a lens element configured to implement a predefined lens function. For example, the predefined optical function (e.g., the predefined lens function) may include focusing light, diffracting light, collimating light, diverging light, projecting a light pattern, etc. The term“optical component” may describe a component including an optical element, and further including additional elements such as a substrate, an aperture, and the like. Aspects discussed in relation to an optical component may apply in a corresponding manner to the respective optical element, and vice versa.

[0021] FIG.1A shows a light-based sensing device 100 in a schematic representation, according to various aspects. The device 100 may be an exemplary device that includes one or more optoelectronic devices for light emission and / or light detection. It is understood, that the device 100 provides an exemplary and simplified configuration of a possible application of an optoelectronic device as described herein. In general, the light-based sensing device 100 may include a first optoelectronic device 102 configured to emit light, and a second optoelectronic device 104 configured to detect light. The device 100 may further include a processing circuit 106 configured to control an operation of the device 100, e.g. the processing circuit 106 may be configured to control a light emission by the first optoelectronic device 102 and may be configured to process data related to light detection by the second optoelectronic device 104.

[0022] In general, the device 100 may be configured for any desired application. In an exemplary configuration, which may represent a relevant use case for an optical component as described herein, the device 100 may be configured as a three-dimensional sensor, illustratively as a depth sensor. As other examples, the device 100 may be configured as a time-of-flight sensor, a proximity sensor, a stereo vision sensor, and the like.

[0023] The device 100 may be configured to carry out light-based sensing (or light-based detection) in a field of view 110. In this regard, the processing circuit 106 may be configured to instruct the light-emitting optoelectronic device 102 to emit light, e.g. the processing circuit may trigger or initiate a light emission by the first optoelectronic device 102. The first optoelectronic device 102 may emit light 108 towards a field of illumination of the first optoelectronic device 102. The field of illumination may at least partially overlap with the field of view 110 of the device 100, e.g. with the field of view of the light-detecting optoelectronic device 104. In some aspects, the field of illumination of the first optoelectronic device 102 may correspond to the field of view of the second optoelectronic device 104 (illustratively, the field of illumination may coincide with the field of view 110).

[0024] The first optoelectronic device 102 may be configured to emit light according to any suitable emission scheme, depending on the type of sensing / detection to be implemented. As an example, the first optoelectronic device 102 may be configured to emit light according to a predefined light pattern, e.g. a grid of light dots or a grid of lines. This configuration may be provided, for example, for face-recognition applications, in which the distortion of the emittedpattern is associated to the profile of an object (e.g., a person) in the field of view 110 of the device 100. As another example, the first optoelectronic device 102 may be configured to emit a light pulse, or a sequence of light pulses. This configuration may be provided, for example, for time-of-flight measurements, in which the round-trip time of the emitted light pulses is calculated to map the presence of objects in the field of view 110, and their properties such as distance from the device 100, speed, direction of motion, and the like.

[0025] The second optoelectronic device 104 may be configured to detect light 112. Illustratively, the second optoelectronic device 104 may be configured to receive light from the field of view 110, e.g. a back-reflection of the emitted light 108, and deliver a signal representative of the received light. As an example, the second optoelectronic device 104 may deliver a signal representative of a (distorted) pattern of the detected light 112. In this scenario, the processing circuit 106 may be configured to determine properties of the object that back- reflected the emitted pattern by analyzing the distortion (e.g., a phase variation between light dots in the emitted pattern and in the detected pattern). For example, the processing circuit 106 may be configured to reconstruct a shape of the object (e.g., a face) based on the distorted pattern. As another example, the second optoelectronic device 104 may deliver a signal representative of an arrival time of a light pulse at the second optoelectronic device 104. In this scenario, the processing circuit 106 may be configured to determine a time-of-flight of the light by using the emission time of the emitted light 108 and the arrival time of the reflected light 112, as known in the art.

[0026] It is understood that the representation in FIG.1 A may be simplified for the purpose of illustration, and that the light-based sensing device 100 may include additional components with respect to those show. For example, the device 100 may include one or more amplifiers to enhance the light emission and / or light detection, one or more filters to select a wavelength bandwidth to reduce the impact of ambient light, transmitter optics, receiver optics, scanning elements (e.g., a MEMS mirror) to scan the field of illumination, analog-to-digital converters, and the like.

[0027] FIG. IB shows an optoelectronic device 120 in a schematic representation, according to various aspects. The optoelectronic device 120 may be an exemplary configuration of the lightemitting optoelectronic device 102 or the light-detecting optoelectronic device 104 described in relation to FIG.1A. In general, the optoelectronic device 120 may include an active optoelectronic component 122 configured for emitting or detecting light, an optical component 124 to direct light towards a field of illumination or to direct light towards a light-detecting optoelectronic component, and a control circuit 126 to control an operation of the optoelectronicdevice 120. It is understood that the optoelectronic device 120 may also include more than one active optoelectronic component 122, e.g. each associated with a corresponding optical component 124. For the sake of brevity the “active” optoelectronic component 122 may also be referred simply as optoelectronic component 122.

[0028] In this regard, the term “active” in relation to the optoelectronic component 122 may be used to indicate that the optoelectronic component 122 may implement an active function, e.g. may actively emit light upon receiving a corresponding signal (e.g., a driving current) or may actively detect light by generating a corresponding detection signal (e.g., a photo current). The term “active” may thus be used to distinguish the optoelectronic component 122 from other types of optoelectronic components that manipulate light in a passive manner, e.g. without the possibility of actively driving the optoelectronic component, e.g. via a corresponding driving current.

[0029] Possible adapted configurations of the optical component 124 will be discussed in further detail in relation to FIG.2A to FIG.2H. In brief, the optical component 124 may be configured to define a field of illumination (for light emission) or a field of view (for light detection) of the active optoelectronic component 122.

[0030] In a preferred configuration, the active optoelectronic component 122 may be configured to emit light. In this scenario, the optoelectronic component 122 may be or include a light source configured to emit light through the optical component 124. Illustratively, the optical component 124 may be configured to direct the light emitted by the light source into a field of illumination of the optoelectronic device 120 (e.g., a field of illumination of the device 100). The optical component 124 may be configured to define a field of illumination for the light source. Additionally or alternatively, the optical component 124 may be configured to project the light emitted by the light source as a light pattern (e.g., as a dot pattern).

[0031] As an example, the light source may be or include a laser source, e.g. a Vertical Cavity Surface Emitting Laser (VCSEL) or a VCSEL-array. The light source may be configured to emit light having a predefined wavelength, for example in the visible range (e.g., from about 380 nm to about 700 nm), infrared and / or near-infrared range (e.g., in the range from about 700 nm to about 5000 nm, for example in the range from about 860 nm to about 1600 nm, for example at 940 nm), or ultraviolet range (e.g., from about 100 nm to about 400 nm). As an example, the light source may be not eye safe in absence of a suitable optical component, e.g. the light source may be classified above Class 1 in terms of laser class.

[0032] It is however understood that, in other aspects, the optoelectronic component 122 may be configured for receiving light and generating a corresponding electrical signal, e.g. acorresponding electrical current. In this scenario, the optoelectronic component 122 may be or include a light sensor (e.g., a photo diode), e.g. as part of a detection system or as part of a solar cell, as examples. The light sensor may be configured to be sensitive for light having wavelength in a predefined range, e.g. one of the ranges described above in relation to the light source. As examples, a light sensor may include at least one of a PIN photo diode, an avalanche photo diode (APD), a single-photon avalanche photo diode (SPAD), or a silicon photomultiplier (SiPM). In this configuration, the optical component 124 may define a field of view of the light sensor, e.g. to collect light from the field of view and direct the collected light onto the light sensor.

[0033] In some aspects, the optical component 124 may include an aperture element to define an optical aperture for the optical component 124 (not shown, see FIG.2A to FIG.2H). In some aspects, the optical component 124 may include an interlock feature, illustratively an electrically conductive trace 132 that allows monitoring the presence or occurrence of damages to the optical component 124 (or a detaching of the optical component 124 from a housing 128 of the optoelectronic device 120) by monitoring an electrical parameter associated with the electrically conductive trace. For example in relation to light emission, the electrically conductive trace 132 allows monitoring the safety of the light emission through the optical component 124 with increased reliability.

[0034] In general, a damaged condition of the optical component 124 may be or include any variation in a state of the optical component 124 capable of causing a variation in the electrical behavior of the electrically conductive trace 132 (e.g., a variation in capacitance, resistance, etc. as discussed below in further detail). As an example, a damaged condition of the optical component 124 may be the presence or the occurrence of a crack in the optical component 124 (e.g., in an optical element of the optical component 124). As another example, a damaged condition of the optical component 124 may be a detaching of the optical component 124, e.g. a detaching from the housing 128 of the corresponding optoelectronic device 120. The damaged condition of the optical component 124 may thus include a state the optical component 124 that may lead to light emission (or detection) different from a predefined light emission (or light detection), e.g. by allowing light to be emitted in undesired directions, or at an undesired power, and the like.

[0035] According to various aspects, the control circuit 126 may be configured to control the optoelectronic component 122 based on the electrical behavior of the electrically conductive trace 132, e.g. based on the occurrence of a damaged condition of the optical component 124. Illustratively, the control circuit 126 may be configured to transmit a control signal to theoptoelectronic component 122 (e.g., to a driver of the optoelectronic component 122), and the control signal may instruct a change in the operation of the optoelectronic component 122 in response to the control circuit 126 detecting a damaged condition of the optical component 124. The control signal may instruct or trigger a safety-mechanism at the optoelectronic component 122.

[0036] For example, the control circuit 126 (and the corresponding control signal) may be configured to instruct the optoelectronic component 122 to stop operating in case the control circuit 126 detects a damaged condition of the optical component 124. In case the optoelectronic component 122 is a light source, the control circuit 126 may be configured to instruct the light source (e.g., a driver of the light source) to adapt the light emission in response to the detection of the damaged condition of the optical component 124. In some aspects, the control circuit 126 may be configured to instruct the optoelectronic component 122 to change at least one parameter of the light emission upon detecting the damaged condition of the optical component 124. The at least one parameter may include any parameter that may affect eye-safety, e.g., an intensity of emitted light (e.g., reduced to zero), a wavelength of emitted light, a pulse rate of the emitted light, and the like.

[0037] As an example, the control circuit 126 may be configured to instruct an interruption of light emission by the light source upon detecting the damaged condition of the optical component 124. As another example, additionally or alternatively, the control circuit 126 may be configured to instruct the light source to reduce the power of the emitted light upon detecting the damaged condition of the optical component 124. As a further example, additionally or alternatively, the control circuit may be configured to instruct the light source to change the wavelength of the emitted light (e.g., to a wavelength less likely to cause eye damage) upon detecting the damaged condition of the optical component 124.

[0038] The control circuit 126 may be configured to monitor an electrical behavior of the electrically conductive trace 132, and to detect a damaged condition of the optical component 124 based on the monitored electrical behavior of the electrically conductive trace 132. Illustratively, the control circuit 126 may be configured to associate a detected variation in the electrical behavior of the electrically conductive trace 132 to a corresponding damaged condition of the optical component 124.

[0039] The control circuit 126 may be configured to cause a flow of electrical current through the electrically conductive trace 132. Illustratively, the control circuit 126 may be electrically conductively coupled with the electrically conductive trace 132, e.g. at corresponding contact pads. As an exemplary configuration, the control circuit 126 may include or control a voltagesource to apply a first voltage at a first contact pad of the electrically conductive trace 132 and a second voltage at a second contact pad of the electrically conductive trace 132 to induce a voltage difference across the electrically conductive trace 132 and a corresponding current flow through the electrically conductive trace 132.

[0040] The control circuit 126 may be further configured to monitor an electrical parameter associated with the flow of electrical current through the electrically conductive trace 132. Illustratively, the control circuit 126 may operate as a monitoring circuit to monitor the behavior of the electrically conductive trace 132. The control circuit 132 may be configured to monitor variations in the electrical parameter (or in more than one electrical parameter). Any suitable electrical parameter that may be associated to a corresponding damaged condition of the optical element 124 may be selected. As examples, which have been found to provide a reliable indication of the occurrence of a damaged condition, the electrical parameter may include one or more of a current level of a current through the electrically conductive trace 132, a voltage level of a voltage over the electrically conductive trace 132, an electrical resistance defined by the electrically conductive trace 132, and / or an electrical capacitance defined by the electrically conductive trace 132.

[0041] The control circuit 126 may be further configured to identify the damaged condition of the optical component 124 based on a variation of the monitored electrical parameter. Illustratively, the control circuit 126 may be configured to detect the occurrence of a damaged condition of the optical component 124 based on a variation of the monitored electrical parameter. For example, the control circuit 126 may configured to determine the occurrence of a damaged condition if the value (e.g., the magnitude) of the variation of the monitored electrical parameter is in a predefined range, e.g. if the value of the variation of the monitored electrical parameter is greater than a predefined threshold. The predefined range may be a range of values for the variation of the electrical parameter that are known to be associated with a damaged condition of the optical component 124. In a corresponding manner, the control circuit 126 may configured to determine the occurrence of a damaged condition if the variation of the monitored electrical parameter is outside a predefined range, e.g. a range of acceptable values for the variation of the electrical parameter.

[0042] As a further example, additionally or alternatively, the control circuit 126 may be configured to identify a damaged condition of the optical component 124 based on an interruption of the flow of electrical current through the electrically conductive trace 132 (illustratively, by detecting a variation of the current level down to substantially zero). Illustratively, the control circuit 126 may be configured to determine the occurrence of thedamaged condition in case the control circuit 126 detects an interruption of the current flow through the electrically conductive trace 132.

[0043] In a preferred configuration, the control circuit 126 may be configured to detect the damaged condition of the optical component 124 according to a variation in the electrical resistance defined by the electrically conductive trace 132. The control circuit 126 may continuously monitor the resistance of the trace 132, and in case the trace 132 is damaged or the optical component 124 is not present anymore (detached from the module) then the control circuit 126 may instruct a switching off of the light source power supply for eye safety (thus providing eye safety interlock). The resistance is an electrical parameter that allows a simple, yet efficient monitoring of the presence or occurrence of the damaged condition. Illustratively, in case there are cracks, or a detaching of the optical component, the resistance defined by the trace 132 may increase.

[0044] According to various aspects, the control circuit 126 may be configured to generate an output signal representative of the damaged condition of the optical component 124. The output signal may represent the occurrence of the damaged condition, e.g. to prompt maintenance or replacement of the optical component 124. Additionally or alternatively, the output signal may represent the type of damaged condition, e.g. a crack, a detaching, etc. In some aspects, the control circuit 126 may be configured to generate a control signal (e.g., as part of the output signal, or as separate signal) to instruct a safety procedure in the optoelectronic device 120, as discussed above.

[0045] According to various aspects, the control circuit 126 may include or may be coupled with a memory (not shown). For example, the memory may be part of the optoelectronic device 120. As another example, the memory may be external to the optoelectronic device 120 and the control circuit 126 may be communicatively coupled with the memory (e.g., with the cloud). The memory may store predefined values of the monitored electrical parameter or electrical parameters, e.g. predefined values of the variation of the monitored electrical parameter(s). For example, the memory may store the value of a variation of the electrical parameter(s) associated with a corresponding damaged condition of the optical component 124 (e.g., as a look-up table). The control circuit 126 may be configured to compare a value of a detected variation of the electrical parameter with the values stored in the memory to identify a damaged condition of the optical component 124.

[0046] According to various aspects, the optoelectronic device 120 may include a substrate 130, and the optoelectronic component 122 may be integrated onto the substrate 130. For example, the substrate 130 may be a printed circuit board. In some aspects, the optoelectroniccomponent 122 (e.g., the light source) and the control circuit 126 of the optical component may be integrated onto the same substrate 130. This configuration may provide a robust arrangement of the optoelectronic device 120.

[0047] According to various aspects, the optoelectronic device 120 may include a housing 128. The housing 128 may enclose the optical component 124 and the optoelectronic component 122. The housing 128 may provide mechanical support to the optical component 124, e.g. the housing 128 may be prepared for placement of the optical component 124 (e.g., the housing may include a recess to accommodate the optical component 124). As examples, the housing 128 may be a plastic spacer, a ceramic substrate, an organic substrate, or a leadframe. The housing 128 may also be referred to as package element.

[0048] The housing 128 may include one or more conductive elements (not shown) configured to electrically conductively connect the electrically conductive trace 132 of the optical component 124 with the control circuit 126. For example, the conductive elements may connect the electrically conductively trace 132 with the substrate 130 on which the control circuit 126 is disposed. Illustratively, the electrical coupling between the control circuit 126 and the electrically conductive trace 132 may be realized via the conductive elements of the housing 128. As examples, the housing 128 may be a plastic spacer with LDS (laser direct structuring) conductive elements, a ceramic substrate with conductive elements, an organic substrate with conductive elements, or a leadframe with conductive elements.

[0049] Illustratively, the housing 128 may include one or more walls, and the control circuit 126 may be electrically conductively connected with the electrically conductive trace 132 via one or more electrically conductive elements disposed in or on the one or more walls of the housing 128. The electrically conductive elements may be disposed on the outside of the wall or on the inside of the wall of the housing 128. This configuration may provide a robust electrical connection between the control circuit 126 and the electrically conductive trace 132 in view of the further support provided by the housing 128.

[0050] It is understood that the representation of the optoelectronic device 120 in FIG. IB may be simplified for the purpose of illustration, and that the optoelectronic device 120 may include additional components with respect to those shown. As examples, the optoelectronic device 120 may include one or more capacitors, a conductive adhesive for coupling the optical component 124 to the housing 128, a driver for the optoelectronic component 122, analog-to-digital converters, and the like.

[0051] In general, the optical component 124 may include, in addition to the interlock feature, an aperture element defining an aperture for the light emitted by the optoelectronic device 100or detected at the optoelectronic device 100. As mentioned above, in a conventional configuration, the aperture element may be disposed on the so-called “A-side” of the optical component 124, e.g. the side facing the field of illumination in case of a light-emitting optoelectronic component 122. Illustratively, in a conventional configuration the aperture element is disposed at the output side of the optical substrate of the optical component 124. Furthermore, the aperture element and the electrically conductive trace may be usually disposed on opposite sides of an optical substrate of the optical component 124.

[0052] The present disclosure is based on the realization that disposing the aperture element at the “B-side” of the optical component 124 (e.g., at the side facing the light source in case of a light-emitting optoelectronic component 122) provides advantageous properties for transmission of light in that it reduces or prevents blocking an excessive amount of light at the output side of the light-emitting optoelectronic component 122. Illustratively, within the optical substrate (e.g., in glass) there may be an expansion of the beam, so that disposing the optical aperture at the output side may lead to blocking more light than originally intended (illustratively, in view of the expanded area covered by the light beam). The beam is expanding on the A-side, so that the normal angle increases significantly on the A-side due to refraction at the glass to air interface. Furthermore, the present disclosure is based on the realization that disposing the aperture element and the electrically conductive trace at the same side of the optical substrate may be conveniently achieved by way of a common fabrication process (see also FIG.4).

[0053] FIG.2A to FIG.2H show possible configurations of an optical component 200a-200h in a schematic representation according to various aspects. The optical component 200a-200h may be configured according to the approach proposed herein, and may be for use, for example, in an optoelectronic device (e.g., in the optoelectronic device 100). In some aspects, the optical component 200a-200h may provide an adapted configuration of the optical component 124 discussed in relation to FIG. IB. It is understood that an application of the optical component 200a-200h in an optoelectronic device may be the most relevant use case for the configuration described herein, but in principle the optical component 200a-200h may also be used in other types of applications and / or devices.

[0054] In general, the optical component 200a-200h may include an optical substrate 202 and an optical element 204 coupled with the optical substrate 202. The optical element 204 may be disposed on the optical substrate 202, e.g. directly on the optical substrate 202 (as shown in FIG.2G and FIG.2H), or indirectly on the optical substrate 202 (as shown in FIG.2A to FIG.2F). Illustratively, the optical substrate 202 may provide mechanical support to the optical element204. In general, the optical element 204 may be configured to allow transmission of light in a predefined wavelength range, e.g. in one of the ranges discussed above in relation to the optoelectronic component 122. For example, the predefined wavelength range may be or include a sub-band in the near-infrared wavelength range, e.g. a sub-band centered around 940 nm. Such wavelength range may be of particular interest for applications in face recognition, virtual reality, or augmented reality. It is however understood that in principle the optical element 204 (and substrate 202) may be adapted for operation in any suitable wavelength range.

[0055] The optical substrate 202 may be configured to be transparent for light with wavelength in the predefined wavelength range, e.g. in the range of emission / detection of an optoelectronic device in which the optical component 200a-200h should be integrated. The optical substrate 202 may include or may consist of any suitable material that is transmissive for the desired wavelength(s). As examples, the optical substrate 202 may include or may consist of glass, such as borosilicate glass, or plastic (e.g., a transparent polymer). In some aspects, the optical substrate 202 may include a wafer, e.g. an optical wafer (e.g., a glass wafer). In some aspects, the optical substrate 202 may be configured to filter out light with wavelength outside a predefined wavelength range. For example, the material of the substrate may be transmissive only in the desired wavelength range. As another example, the optical substrate 202 may have a coating configured to block light with wavelength outside the predefined wavelength range.

[0056] In general, the dimensions of the optical substrate 202 may be adapted based on the desired use case, e.g. based on the overall dimensions of an optoelectronic device in which the optical component 200a-200h is integrated. With regard to the thickness of the optical substrate 202 (illustratively, a dimension in a direction parallel to the optical axis of the optical component 200a-200h), the optical substrate 202 may have a thickness in the range from 300 pm (micrometers) to 1.5 mm (millimeters), for example in the range from 500 pm to 1.1 mm. As a numerical example, the optical substrate 202 may have a thickness of at least 900 pm. Such values and ranges for the thickness have been found suitable for an optical component 200a-200h as described herein, e.g. in terms of robustness, beam clipping, and the like. In particular, a thicker substrate 202 (e.g., at least 900 pm thick) reduces the risk of beam clipping when the aperture element is disposed at the B-side, since the beam footprint is smaller on B-side than on A-side. It is however understood that in principle the optical substrate 202 may have a thickness in a different range.

[0057] In general, the optical substrate 202 may have a planar configuration. Illustratively, the optical substrate 202 may be a planar substrate on which the optical element 204 is provided(e.g., formed, disposed). In this regard, the optical substrate 202 may have a lateral extension in the direction perpendicular to the optical axis of the optical component / optical element 204 much greater than the lateral extension in the direction parallel to the optical axis. Illustratively, a width of the optical substrate 202 (or a diameter in case of circular shape) may be greater than the thickness of the optical substrate 202, e.g. at least two times greater, at least five times greater, for example at least ten times greater, for example at least fifty times greater. The optical substrate 202 may be a portion of a (transparent) sheet or wafer on which the optical element 204 is provided.

[0058] In general, the optical element 204 may be configured to provide a field of illumination or a field of view of an optoelectronic component (e.g., the optoelectronic component 122 in FIG. IB). For example, considering light emission, the optical element 204 may be configured to shape the emitted light to achieve a predefined field of illumination. The optical element 204 may be configured to be transmissive for light with wavelength in the above-mentioned predefined wavelength range, for example in the range of emission of the corresponding optoelectronic device or in the range of detection of the corresponding optoelectronic device. Illustratively, the optical element 204 may be configured to allow light to pass through the optical element 204, from one side of the optical element 204 to the other side of the optical element 204 while providing a shaping of the light.

[0059] Illustratively, the optical element 204 may be configured to manipulate light according to a predefined optical function, e.g. a predefined lens function. The optical element 204 may be configured to implement the predefined optical function for light with wavelength in the predefined wavelength range, illustratively the operating wavelength range of the optical element 204. For example, the optical element 204 may be configured as a lens to implement a predefined lens function, e.g. the optical element 204 may be configured to cause diffraction of light according to the predefined lens function. As an example, the optical element 204 may be configured to collimate light (e.g., for light emission), or the optical element 204 may be configured to focus light (e.g., onto a light sensor, for example for light detection). In various aspects, the optical element 204 may be or include a lens element, e.g. a micro-lens array (MLA). As another example, the optical element 204 may be configured to receive light and output (e.g., generate) a light pattern, such as for example a stripe pattern or a dot pattern. In various aspects, the optical element 204 may be a diffractive optical element (DOE).

[0060] A micro-lens array or a diffractive optical element are of particular interest for applications such as face recognition, virtual reality, gesture tracking, and the like. It is however understood that the optical element 204 may be or include any suitable type of optical elementto control or influence the properties of the emitted / collected light according to the desired application and according to the configuration of the optoelectronic device in which the optical component 200a-200h is integrated.

[0061] A micro-lens array may be an array including a plurality of micro-lenses (also referred to as lenslets). The micro-lenses may be arranged within the array in a one-dimensional or two-dimensional fashion. A micro-lens may have a diameter in the nanometer range, for example in the range from 5 nm to 20 nm, for example a diameter less than 10 nm. A pitch of the array (e.g., a center-to-center distance between adjacent micro-lenses) may be in the range from 10 pm to 1 mm, for example in the range from 50 pm to 500 pm. The thickness of the micro-lens array may be in the range from about 500 pm to about 5 mm, e.g. in the range from about 1 mm to about 3 mm. In some aspects, the micro-lens array may include micro-lenses arranged in corresponding groups, and the micro-lenses belonging to different groups may have different properties, e.g. a different focal length, a different pitch, a different curvature, etc.

[0062] According to various aspects, the optical component 200a-200h may include an aperture element 206 configured to define an aperture for transmission of light through the optical element 204. Illustratively, the aperture element 206 may be configured to define an opening for the optical element 204 to, during an operation of the optical component 200a-200h, partially block light and partially allow light to pass through the opening. The aperture element 206 may thus be an optical aperture that confines an area (and a volume) in which light may propagate through the optical component 200a-200h (and, accordingly, through the optical element 204). The aperture element 206 may include a border portion configured to block light (e.g., the material of the border portion may block the light passing through the optical element 204). The (e.g., central) area surrounded by the border portion, illustratively a clear aperture, may be an empty area that allows light to pass through.

[0063] The aperture element 206 may thus be configured (e.g., structured) to spatially limit the propagation of light passing through the optical element 204. Illustratively, the aperture element 206 may be configured to define a clear aperture in which light may be transmitted through the optical element 204. The clear aperture may be an area free of the material of the aperture element 206, and surrounded by border portions of the aperture element 206. The aperture element 206 may thus include or consist of a different material with respect to the optical substrate 202, in particular a material that allows blocking light compared to the material of the optical substrate 202 which instead allows light to pass through.

[0064] The shape of the area through which the aperture element 206 allows light to pass through may be adapted according to a desired configuration / operation. In a preferredconfiguration, the aperture element 206 may define an opening (also referred to as aperture) that is symmetric around the optical axis of the optical component 200a-200h. Illustratively, the aperture element 206 may define an opening that is centered around the optical axis and that extends in the plane perpendicular to the optical axis by a same lateral extension in all directions. This configuration may allow a more uniform transmission of light through the optical component 200a-200h. As exemplary shapes, the aperture element 206 may define a circular aperture, a square aperture, a rectangular aperture, or an elliptical aperture. It is however understood that in principle the aperture element 206 may also define apertures with a different shape.

[0065] The material of the aperture element 206 may be configured (e.g., selected) to allow blocking light during operation of the optical component 200a-200h. Illustratively, the aperture element 206 (e.g., the border portion) may have a transmittance of less than 0.1%, e.g. for light in the predefined wavelength range. In general, the aperture element 206 may have a transmittance that is substantially zero outside of the (clear) aperture defined by the aperture element 206. This allows preventing the light from propagating (and being emitted) outside of a desired region or volume. In this regard, the aperture element 206 may include any suitable material that allows achieving the desired transmittance properties. In a preferred configuration, which allows an efficient fabrication process (e.g., in combination with the fabrication of an electrically conductive trace), the aperture element 206 may include or may be made of chromium (Cr), for example black chromium (illustratively, a chemically altered version of chromium to obtain a black color that enhances the light-blocking properties of the aperture element 206).

[0066] The dimensions of the aperture element 206 and of the defined aperture may be adapted according to the desired application and overall configuration of the optical component 200a-200h. In general, the aperture defined by the aperture element 206 may be smaller than the optical element 204. Illustratively, a surface area of the aperture may be smaller than a surface area of the optical element 204. This may provide the confinement of at least part of the light that propagates through the optical element 206. The border portion of the aperture element 206 may thus at least partially overlap with the optical element 204, so that the aperture is in correspondence of (only) a portion of the optical element 204, e.g. a central portion of the optical element 204.

[0067] According to various aspects, the aperture element 206 may be or include a layer of material that is non-transparent for light in the operating wavelength range of the optical component, and may include a portion in which the material of the layer is not present to definethe opening through which light is allowed to pass. The aperture element 206 may be a layer of material disposed (e.g., deposited) on the optical substrate 202, and including a portion free of the material of the layer to define the opening. In general, the aperture element 206 may be in direct physical contact with one of or both the optical substrate 202 and the optical element 204, as shown in FIG.2 A to FIG.2H.

[0068] As mentioned above, the present disclosure is based on the realization that the aperture element 206 may be advantageously disposed on the “B-side” of the optical substrate 202, e.g. at the side facing the optical element 204. In this configuration, considering for example light emission, the (emitted) light passes through the optical element 204 and the aperture defined by the aperture element 206 before propagating in the optical substrate 202. This ensures that beam expansion in the substrate 202 does not lead to excessive beam clipping, as it would be the case with an aperture element disposed at the opposite side of the substrate.

[0069] In general, the aperture element 206 may thus be disposed optically downstream of the optical element 204 and optically upstream of the optical substrate 202 (considering an operation of the optical component 200a-200h), so that light passes through the optical element 204, then through the aperture, and then through the optical substrate 202.

[0070] Considering integration in a light-emitting optoelectronic device, the optical component 200a-200h may be disposed with respect to an active optoelectronic component of the device (e.g., a light source) in such a way that the optical element 204 (e.g., the MLA) is disposed optically upstream of the optical substrate along an emission direction of the light emitted by the active optoelectronic component. Considering integration in a light-detecting optoelectronic device, the optical component 200a-200h may be disposed with respect to an active optoelectronic component of the device (e.g., a photo diode) in such a way that the optical element 204 (e.g., the MLA) is disposed optically upstream of the optical substrate along a receive direction of the light detected at the active optoelectronic component.

[0071] As shown in FIG.2A, in a simple configuration the optical component 200a may include the aperture element 206 disposed between the optical substrate 202 and the optical element 204 (e.g., the MLA). In this configuration, the optical component 200a may be free of an electrically conductive trace for monitoring the presence or occurrence of damages to the optical component 200a. This configuration provides thus a simple arrangement to exploit the concept of disposing the aperture element 206 such that light passes through the aperture before an expansion in the optical substrate 202.

[0072] According to various aspects, as shown in FIG.2B to FIG.2H, the optical component 200b-200h may further include an interlock feature 208. The interlock feature 208 may be anelectrically conductive trace 208 configured to allow presence detection and detection of a damaged condition of the optical component 200b-200h by a variation of an electrical parameter of the electrically conductive trace 208, as discussed in relation to the electrically conductive trace 132 in FIG. IB. Illustratively, the electrically conductive trace 208 may be configured (e.g., disposed) such that a damage in the optical component 200b-200h and / or a detaching of the optical component 200b-200h from the housing of a corresponding optoelectronic device causes a variation in the electrical parameter.

[0073] As discussed above, the detection of such variation (e.g., by a control circuit of the optoelectronic device) allows identifying the presence or the occurrence of a dangerous situation that may prompt a corrective action. Illustratively, the variation of the electrical parameter (e.g., a variation above a predefined threshold) may indicate an incorrect state or disposition of the optical component 200b-200h which may lead to a defective operation of the optical component (and of the corresponding optoelectronic device). For example, the variation of the electrical parameter may indicate that light is being emitted or would be emitted in undesired (non-predefined) directions, or at an excessive optical power, and may prompt an interruption of light emission.

[0074] According to various aspects, the electrically conductive trace 208 may include a plurality of contact pads. The contact pads may provide electrical contact points for electrically contacting the electrically conductive trace 208, e.g. with a control circuit of an optoelectronic device (e.g., the control circuit 126 in FIG. IB). The electrically conductive trace 208 may include at least two contact pads. In general, the contact pads may be disposed outside of the perimeter of the optical element 204, so that the contact pads do not interfere with the transmission of light through the optical element 204. Illustratively, the contact pads may be disposed outside of the optical aperture defined by the aperture element 206.

[0075] In a simple configuration, the plurality of contact pads may include two contact pads. In a more elaborate configuration, the plurality of contact pads may include four contact pads. A configuration with four contact pads may provide using two of the contact pads for applying an electrical signal to the electrically conductive trace 208, and using other two of the contact pads for monitoring the electrical behavior of the electrically conductive trace 208. This configuration provides thus a more reliable arrangement for monitoring the presence or occurrence of damages in the optical component 200b-200h.

[0076] In an exemplary configuration, the contact pads may be disposed at respective trace ends of the electrically conductive trace 208. It is however understood that in principle the contact pads may be disposed at any suitable position along the electrically conductive trace208, e.g. to adapt to the shape of the electrically conductive trace 208. It is also understood that the electrically conductive trace 208 may include any suitable number of contact pads, e.g. two, three, four, five, ten, more than ten, depending on the desired complexity. In general, the contact pads may facilitate the monitoring of the electrical parameter associated with the electrically conductive trace 208. In various aspects, the electrical parameter may be or include the electrical resistance defined by the electrically conductive trace between at least two contact pads.

[0077] According to the configuration proposed herein, the aperture element 206 and the electrically conductive trace 208 may be disposed at the same side of the optical substrate 202. Illustratively, the aperture element 206 and the electrically conductive trace 208 may be formed or arranged not at opposite sides of the optical substrate 202 (as in a conventional configuration), but rather may be both on one side of the optical substrate 202. Illustratively, one of the main surfaces of the optical substrate 202 may face both the aperture element 206 and the electrically conductive trace 208. The aperture element 206 and the electrically conductive trace 208 may be disposed both optically upstream of the optical substrate 202, considering an operation of the optical element 200b-200h, as discussed above. This configuration enhances the confinement of the light by exploiting the additional area provided by the electrically conductive trace 208 to supplement the border portion of the aperture element 206, and also enables a time- and cost-efficient fabrication (see FIG.4).

[0078] In principle, various configurations are possible for the disposition of the aperture element 206 and electrically conductive trace 208, e.g. with respect to one another or within the optical component 200b-200h, while still maintaining the disposition of both at the same side of the optical substrate. FIG.2B to FIG.2H illustrate various exemplary dispositions that have been found suitable to implement the strategy proposed herein and that may facilitate the fabrication process (e.g., see configuration 200b in FIG.2B). It is however understood that other configurations (e.g., with additional layers) may be provided.

[0079] In a preferred configuration 200b, 200h shown in FIG.2B and FIG.2H, the aperture element 206 and the electrically conductive trace 208 may be disposed co-planar with respect to one another. In this configuration, the aperture element 206 and the electrically conductive trace 208 may be disposed (e.g., formed) on the same plane. For example, the aperture element 206 and the electrically conductive trace 208 may both be disposed in direct contact with the optical substrate 202 (as shown in FIG.2B). As another example, the aperture element 206 and the electrically conductive trace 208 may both be disposed in direct contact with the optical element 204 but may not contact the optical substrate 202 (as shown in FIG.2H). Illustratively,in this configuration 200b, 200h, the aperture element 206 and the electrically conductive trace 208 may extend in the same two-dimensional plane, and the plane may be parallel to the main surface of the optical substrate 202 (and to the main surface of the optical element 204). The co-planar configuration enables a more efficient fabrication process (see also FIG.4).

[0080] In the co-planar configuration the electrically conductive trace 208 may completely laterally surround the aperture element 206 (see also FIG.3A to FIG.3C). Illustratively, the electrically conductive trace 208 may enclose the aperture element 206 in the plane. Stated in a different fashion, the (outer) perimeter of the aperture element 206 may be fully surrounded / fully enclosed by the (inner) perimeter of the electrically conductive trace 208.

[0081] In other configurations, as shown for example in FIG.2C and 2G, the aperture element 206 and the electrically conductive trace 208 may be in contact with one another but may be disposed on different planes, illustratively at a different level or layer with respect to one another. In this configuration, the aperture element 206 may be disposed on a first plane and the electrically conductive trace 208 may be disposed on a second plane, and the first plane and the second plane may be at a respective (different) distance from the optical substrate 202 (along the direction defined by the optical axis). For example, as shown in FIG.2C, the aperture element 206 may be disposed between the optical substrate 202 and the electrically conductive trace 208, and the electrically conductive trace 208 may be disposed between the aperture element 206 and the optical element 204. As another example, as shown in FIG.2G, the optical element 204 may be disposed between the optical substrate and the electrically conductive trace 208, and the electrically conductive trace 208 may be disposed between the optical element 204 and the aperture element 206.

[0082] According to various aspects, as shown in FIG.2B, 2C, and 2F, the aperture element 206 and the electrically conductive trace 208 may be disposed between the optical substrate 202 and the optical element 204. For example, at least one of the aperture element 206 and the electrically conductive trace 208 may be in direct contact with the optical substrate 202, and the other one of the aperture element 206 and the electrically conductive trace 208 may be in direct contact with the optical element 204 (see FIG.2C). As another example, both of the aperture element 206 and the electrically conductive trace 208 may be in direct contact with both the optical substrate 202 and the optical element 204 (see FIG.2B).

[0083] In other aspects, as shown in FIG.2D, 2E, 2G, and 2H the optical element 204 may be disposed between the optical substrate 202 and the electrically conductive trace 208. In this configuration, the electrically conductive trace 208 may be disposed on the optical element 204 (e.g., directly on the surface of the optical element 204, or with an insulating layer 210therebetween), and may face away from the optical substrate 202. For example, as shown in FIG.2D and 2E, the aperture element 206 may be disposed between the optical substrate 202 and the optical element 204, and the optical element 204 may be disposed between the aperture element 206 and the electrically conductive trace 208. As another example, as shown in FIG.2G and FIG.2H, the optical element 204 may be disposed between the optical substrate 202 and both the aperture element 206 and the electrically conductive trace 208.

[0084] In some aspects, the electrically conductive trace 208 may be in direct physical contact with the optical element 204 (as shown, for example, in FIG.2B, 2C, 2E, 2G, and 2H). This may provide a more sensitive detection of damages occurring to the optical element 204 (e.g., a crack in a micro-lens, for example). In other aspects, an electrically insulating layer 210 (as shown in FIG.2D and 2F) may be disposed between the electrically conductive trace 208 and the optical element 204. The electrically insulating layer 210 may enhance the adhesion of the electrically conductive trace 208 to the optical element 204 by providing a suitable interface.

[0085] As exemplary materials, the electrically insulating layer 210 may include or may consist of an oxide or a nitride, such as silicon dioxide, titanium dioxide, silicon nitride, or silicon oxynitride. In the exemplary configuration in FIG.2D and FIG.2F a single electrically insulating layer 210 is illustrated interposed between the electrically conductive trace 208 and the optical element 204. In other aspects, more than one electrically insulating layer 210 may be disposed between the electrically conductive trace 208 and the optical element 204, e.g. a plurality of electrically insulating layers 210, for example including or consisting of different materials (e.g., to tailor the structural properties of the electrically insulating layers). In various aspects, an electrically insulating layer 210 may be a dielectric layer.

[0086] In general, the electrically conductive trace 208 may have any suitable configuration (e.g., shape) to conform to the structure and disposition of the aperture element 206, optical element 204, and optical substrate 202. In a preferred configuration, as shown for example in FIG.2B and FIG.2H, the electrically conductive trace 208 may be disposed to surround the aperture element 206. Illustratively, as mentioned above, the electrically conductive trace 208 may have or define a contour (illustratively, a perimeter) that surrounds a contour of the aperture element 206. This configuration may provide enhancing the confinement of the light provided by the aperture element 206 by the additional coverage provided by the electrically conductive trace 208.

[0087] This configuration may be provided, for example, in case the electrically conductive trace 208 and the aperture element 206 are co-planar. The electrically conductive trace 208 may be disposed laterally adjacent to the aperture element 206 (and substantially in contact with theelectrically conductive trace 208) within the plane on which both the electrically conductive trace 208 and the aperture element 206 are disposed. A space between the electrically conductive trace 208 and the aperture element 206 (on the plane) may be minimized to prevent light from passing through such space. As a numerical example, a distance in the plane between the electrically conductive trace 208 and the aperture element 206 may be less than 20 pm, for example less than 10 pm. Such configuration may also be provided in case the electrically conductive trace 208 and the aperture element 206 are disposed on different planes. In this other configuration, the projection of the electrically conductive trace 208 onto the plane of the aperture element 206 may surround the aperture element 206.

[0088] In general, the electrically conductive trace 208 may have a shape (e.g., a perimeter) following a contour of the optical element 204. Illustratively, the electrically conductive trace 208 may have a perimeter following (or corresponding to) the perimeter of a surface of the optical element 204. As examples, the electrically conductive trace 208 may have a circular shape, a rectangular shape, a square shape, an elliptical shape, or the like.

[0089] In some aspects, the electrically conductive trace 208 may include a plurality of windings, e.g. the electrically conductive trace 208 may include a plurality of concentric trace portions (see also FIG.3A to FIG.3C). A configuration with a plurality of windings may allow covering additional surface area with the electrically conductive trace 208. To enhance the light-confining function of the electrically conductive trace 208, a space between adjacent windings may be less than 100 pm, for example less than 50 pm, for example less than 10 pm.

[0090] In principle, the electrically conductive trace 208 may include any suitable electrically conductive material. For example, the electrically conductive trace 208 may include or may consist of a metal material. In a preferred configuration, to enhance the light-blocking properties of the arrangement, the electrically conductive trace 208 may have a transmittance of less than 0.1%, e.g. for light in the predefined wavelength range. The material of the electrically conductive trace 208 may thus be configured (e.g., selected) to be non-transparent for light in the predefined wavelength range (illustratively, the operating wavelength range of the optical component).

[0091] In case the electrically conductive trace 208 includes an electrically conductive material that does not allow light to pass through (e.g., an opaque material), the electrically conductive trace 208 may be disposed outside of the aperture defined by the aperture element 206. Illustratively, in this configuration the electrically conductive trace 208 may be disposed so that the electrically conductive trace 208 does not overlap with the aperture defined by the aperture element 206.

[0092] In principle, however, the electrically conductive trace 208 may include an electrically conductive material that allows light to pass through (e.g., an at least partially transparent material, such as ITO), the electrically conductive trace 208 may be at least partially disposed in the aperture defined by the aperture element 206. This configuration may allow covering more surface area of the optical element 204 (and optical substrate 202) with the electrically conductive trace 208. For example, in this scenario the electrically conductive trace 208 may have a labyrinth shape overlapping (at least partially) the aperture defined by the aperture element 206.

[0093] In some aspects, to provide a time-efficient fabrication process, the aperture element 206 and the electrically conductive trace 208 may include or may be made of the same material. This may allow forming (e.g., depositing) the aperture element 206 and the electrically conductive trace 208 in a common process. As an example, which has been found to provide advantageous properties in terms of light transmission and electrical conductivity, the aperture element 206 and the electrically conductive trace 208 may include or may be made of chromium.

[0094] In other aspects, the aperture element 206 and the electrically conductive trace 208 may include or may be made of different materials. This configuration may allow a better tailoring of the properties of the aperture element 206 (e.g., in terms of blocking light) and the electrically conductive trace 208 (e.g., in terms of monitoring of the electrical parameter). For example, the aperture element 206 may include or may be made of black chromium, which may increase the efficiency of the aperture element 206 for blocking light, and the electrically conductive trace 208 may include or may be made of chromium.

[0095] The dimensions of the electrically conductive trace 208 may be adapted according to the geometry and configuration of the optical component 200b-200h. In some aspects, the thickness of the electrically conductive trace 208 (illustratively, a dimension in a direction parallel to the optical axis of the optical component 200b-200h) may be selected to provide a desired (low) transmittance in the predefined wavelength range. For example, the thickness of the electrically conductive trace 208 may be configured to provide a transmittance of less than 0.1%, e.g. for light in the predefined wavelength range. As a numerical example, the electrically conductive trace 208 may have a thickness of at least 200 nm. On the other hand, a thin layer thickness for the electrically conductive trace 208 may increase the sheet resistance and in the end the trace resistance (for a given the length and width of the trace), so as to enhance the monitoring of the electrical parameter (e.g., in terms of sensitivity). As a numerical example,the electrically conductive trace 208 may have a thickness in the range from 200 nm to 1 gm, for example in the range from 300 nm to 500 nm.

[0096] It is understood that the representation in FIG.2A to FIG.2H may be simplified for the purpose of illustration, and that the optical component 200a-200h may include additional components with respect to those shown. As an example, the optical component 200a-200h may include a protective layer (e.g., an anti-reflective layer) disposed over the optical substrate 202 (e.g., at the opposite side of the optical substrate 202 with respect to the aperture element 206 and the electrically conductive trace 208). The protective layer may be transmissive of light having wavelength in the desired (predefined) range.

[0097] FIG.3A to FIG.3C show an optical component 300 in a schematic representation according to various aspects. FIG.3A shows a perspective view of the optical component 300. FIG.3B shows an exploded view of the optical component 300. FIG.3C shows a top view of the optical component 300. The optical component 300 may be an exemplary realization of the optical component 200b-200h described in relation to FIG.2B to FIG.2H. It is understood that the aspects discussed in relation to the configuration shown in FIG.3 A to FIG.3C may apply in a corresponding manner to the other possible configurations of an optical component adapted as proposed herein and described in relation to FIG.2B to FIG.2H.

[0098] The optical component 300 may include an optical substrate 302 (e.g., made of glass, for example borosilicate glass) and an optical element 304 coupled with the optical substrate 302. For example, the optical element 304 may be or include a micro-lens array 322. As an example, the micro-lens array 322 may be fabricated via replication from a master mold (e.g., a polymer mold). In this scenario, the optical element 304 may include the micro-lens array 322 disposed on a base layer 314. The optical element 304 may further include a yard portion 316 including the excess material from the replication process.

[0099] The optical component 300 may further include an aperture element 306 and an electrically conductive trace 308. The aperture element 306 and the electrically conductive trace 308 may be co-planar with one another and may be disposed between the optical substrate 302 and the micro-lens array 322. In an exemplary configuration, the aperture element 306 and the electrically conductive trace 308 may include or may be made of chromium. A chromium layer may provide transmission less than 0.1% in the desired wavelength range, e.g. from 920 nm to 960 nm. The sheet resistance of a chromium layer may be about 28 Ohm (±15%). As exemplary dimensions, a width 324 of the electrically conductive trace 308 (e.g., of a trace portion) may be in the range from 45 pm to 55 pm, for example the width may be 50 pm. As another numerical example, a spacing 326 between portions (e.g., windings) of the electricallyconductive trace 308 may be in the range from 1 gm to 11 gm, e.g. the spacing may be 6 gm. As a further numerical example, the electrically conductive trace 308 may have a lateral extension in the plane in the range from 1 mm to 5 mm, for example in the range from 1.5 mm to 3 mm. The lateral extension in the plane may be for example a diameter 328 in the configuration in FIG.3A to FIG.3C, or more in general a total width of the surface area over which the electrically conductive trace 308 is disposed (e.g., formed).

[0100] In the configuration in FIG.3A to FIG.3C, the electrically conductive trace 308 may have a plurality of windings surrounding the aperture element 306. This configuration may extend the area covered by the aperture element, to ensure that light passes through the optical component 300 within a predefined confined volume.

[0101] The optical component 300 may further include contact pads 320, e.g. part of the electrically conductive trace 308 or coupled with the electrically conductive trace 308. The contact pads 320 may include chromium, for example the contact pads 320 may be chromium-gold contact pads. As an exemplary dimension, a contact pad 320 may have a surface area in the range from 0.05 mm2to 1 mm2, for example a contact pad 320 may have a surface area of 0.3*0.25 mm2.

[0102] The optical component 300 may further include an insulating layer 310 disposed between the electrically conductive trace 308 and the micro-lens array 322. The insulating layer 310 may include or be made of silicon dioxide, for example. In some aspects, the optical component 300 may further include an anti -reflective coating 312 to enhance the light emission / light detection properties of the optical component by reducing or suppressing reflection of light. The anti -reflective coating 312 may be disposed on the opposite surface of the substrate 302 with respect to the electrically conductive trace 308 and aperture element 306. FIG.3A and FIG.3B further illustrate alignment features 318 to facilitate the formation (e.g., the deposition) of the various layers during the fabrication.

[0103] FIG.4 shows a schematic flow diagram of a method 400 of fabricating an optical component. The method 400 may be related to the fabrication of the optical component 124, 200a-200h, 300 described in relation to FIG. IB to FIG.3C. It is understood that the aspects described in connection with the optical component 124, 200a-200h, 300 may apply in a corresponding manner to the method 400, and vice versa. In general, the forming of the various parts of the optical component may be carried out with conventional techniques. In this regard, the method 400 may include one or more lithography processes, one or more material evaporation processes, and one or more contact metal fabrication processes.

[0104] The method 400 may include, in 410, providing an optical substrate (e.g., a glass substrate, such as a glass wafer, or in general a substrate capable of transmitting or filtering radiation, e.g. light).

[0105] The method 400 may include, in 420, forming an aperture element and an electrically conductive trace at the same side of the optical substrate. Forming the aperture element and the electrically conductive trace may include carrying out one or more material deposition steps. For example, the deposition may be carried out using photolithographic techniques, e.g. using a mask to delimit the deposition areas for the material of the aperture element and of the electrically conductive trace, and removing the mask after the deposition. In some aspects, the method 400 may include forming the aperture element and the electrically conductive trace co-planar with one another, e.g. on the same plane or layer (e.g., on the same surface of the optical substrate).

[0106] In an exemplary configuration, forming the aperture element and the electrically conductive trace comprises carrying out a single deposition of the material of the aperture element and the electrically conductive trace through a common mask. Illustratively, the method 400 may include using the same material (e.g., chromium) for forming the aperture element and the electrically conductive trace, and may include carrying out a single deposition of that material for forming both the aperture element and the electrically conductive trace during the single deposition. The common mask may be a single mask patterned according to the desired configuration (e.g., shape) of the deposition areas for the aperture element and the electrically conductive trace. Alternatively, the common mask may include two mask portions, one corresponding to the aperture element and one corresponding to the electrically conductive trace. The configuration with a single deposition provides a reduction in the overall costs of the fabrication and also makes it possible to achieve a smaller spacing between the aperture element and the electrically conductive trace.

[0107] In another exemplary configuration, forming the aperture element and the electrically conductive trace comprises carrying out a first deposition of a first material of the aperture element through a first mask, and carrying out a second deposition of a second material of the electrically conductive trace through a second mask. Illustratively, the method 400 may include carrying out subsequent depositions of different materials to form the aperture element and the electrically conductive trace. For example, the method 400 may include carrying out a deposition of black chromium for forming the aperture element, and carrying out a deposition of chromium for forming the electrically conductive trace. This configuration may have a higher cost but provide an enhanced light-blocking property for the aperture. Illustratively, materialsthat allow blocking more light may be less suitable for the electrically conductive trace, so that separate depositions allow a better tailoring of the properties of the aperture element and electrically conductive trace.

[0108] The method 400 may include, in 430, providing an optical element configured to allow transmission of light. The method 400 may include coupling the optical element with the optical substrate. The optical element may be configured to allow transmission (and beam shaping) of light in a predefined wavelength range. For example, the method 400 may include disposing or forming a micro-lens array, e.g. via replication with a master mold. For example, the method 400 may include disposing the optical element such that the aperture element and the electrically conductive trace are disposed between the optical substrate and the optical element. In some aspects, the method 400 may include forming a further electrically insulating layer on the electrically conductive trace and disposing the optical element on the electrically insulating layer.

[0109] The term “electrically conductively connected” that is used herein to describe an electrical connection between one or more trace portions, terminals, nodes, regions, contacts, etc., may be understood as an electrically conductive connection with, for example, ohmic behavior, e.g., provided by a metal or degenerate semiconductor in absence of p-n junctions in the current path. The term “electrically conductively connected” may be also referred to as “galvanically connected”.

[0110] The term “metal material” may be used herein to describe a metal (e.g., a pure or substantially pure metal), a mixture of more than one metal, a metal alloy, an intermetallic material, a conductive metal compound (e.g., a nitride), and the like. Illustratively, the term “metal material” may be used herein to describe a material having an electrical conductivity typical of a metal, for example an electrical conductivity greater than 106S / m at a temperature of 20°C.

[0111] The term “control circuit” (or processing circuit) as used herein may be understood as any kind of technological entity that allows handling of data. The data may be handled according to one or more specific functions that the control circuit may execute. Further, a control circuit as used herein may be understood as any kind of circuit, e.g., any kind of analog or digital circuit. A control circuit may thus be or include an analog circuit, digital circuit, mixed-signal circuit, logic circuit (e.g., a hard-wired logic circuit or a programmable logic circuit), microprocessor, Central Processing Unit (CPU), Graphics Processing Unit (GPU), Digital Signal Processor (DSP), Field Programmable Gate Array (FPGA), integrated circuit, Application Specific Integrated Circuit (ASIC), etc., or any combination thereof.

[0112] The word “exemplary” is used herein to mean “serving as an example, instance, or illustration”. Any embodiment or design described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments or designs.

[0113] The phrase “at least one” and “one or more” may be understood to include a numerical quantity greater than or equal to one (e.g., one, two, three, four, [...], etc.). The phrase “at least one of’ with regard to a group of elements may be used herein to mean at least one element from the group consisting of the elements. For example, the phrase “at least one of’ with regard to a group of elements may be used herein to mean a selection of: one of the listed elements, a plurality of one of the listed elements, a plurality of individual listed elements, or a plurality of a multiple of individual listed elements.

[0114] All acronyms defined in the above description additionally hold in all claims included herein.

[0115] While the invention has been particularly shown and described with reference to specific aspects, it should be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. The scope of the invention is thus indicated by the appended claims and all changes, which come within the meaning and range of equivalency of the claims, are therefore intended to be embraced.List of reference signs100 Light-based sensing device102 First optoelectronic device104 Second optoelectronic device106 Processing circuit108 Emitted light110 Field of view112 Reflected light120 Optoelectronic device122 Optoelectronic component124 Optical component126 Control circuit128 Housing130 Substrate132 Electrically conductive trace200a Optical component200b Optical component200c Optical component200d Optical component200e Optical component200f Optical component200g Optical component200h Optical component202 Optical substrate204 Optical element206 Aperture element208 Electrically conductive trace210 Electrically insulating layer300 Optical component302 Optical substrate304 Optical element306 Aperture element308 Electrically conductive traceElectrically insulating layerAnti -reflective coatingBase layerYardAlignment featureContact padsMicro-lens arrayWidthSpacingDiameterMethodMethod stepMethod stepMethod step

Claims

Claims1. An optical component (200b-200h) comprising: an optical substrate (202) configured to be transparent for light in a predefined wavelength range; an optical element (204) coupled with the optical substrate (202), wherein the optical element (204) is configured to implement a predefined optical function; an aperture element (206) configured to define an opening for the optical element (204) to, during an operation of the optical component (200a-200h), partially block light and partially allow light to pass through the opening; and an electrically conductive trace (208) configured to allow detection of a damaged condition of the optical component (200a-200h) by a variation of an electrical parameter of the electrically conductive trace (208), wherein the aperture element (206) and the electrically conductive trace (208) are disposed at the same side of the optical substrate (202).

2. The optical component (200b-200h) according to claim 1, wherein the aperture element (206) and the electrically conductive trace (208) are disposed between the optical substrate (202) and the optical element (204).

3. The optical component (200b-200h) according to claim 2, further comprising an electrically insulating layer (210) disposed between the electrically conductive trace (208) and the optical element (204).

4. The optical component (200b-200h) according to any one of claims 1 to 3, wherein the aperture element (206) and the electrically conductive trace (208) are disposed co-planar with respect to one another.

5. The optical component (200b-200h) according to any one of claims 1 to 4, wherein the aperture element (206) and the electrically conductive trace (208) comprise or are made of the same material.

6. The optical component (200b-200h) according to one of claims 1 to 5, wherein the electrically conductive trace (208) is disposed to surround the aperture element (206).

7. The optical component (200b-200h) according to one of claims 1 to 6, wherein the optical element (204) is or comprises a micro-lens array (MLA).

8. An optoelectronic device (120) comprising: an active optoelectronic component (122); and an optical component (200b-200h) according to any one of claims 1 to 7.

9. The optoelectronic device (120) according to claim 8, further comprising a control circuit (126) electrically coupled with the electrically conductive trace (208) and configured to monitor the electrical parameter to detect the damaged condition of the optical component (200a-200h).

10. The optoelectronic device (120) according to claim 9, wherein the active optoelectronic component (122) comprises a light source configured to emit light; and wherein the control circuit (126) is configured to instruct the light source to change at least one parameter of a light emission in response to the detection of the damaged condition of the optical component (200a-200h).

11. The optoelectronic device (120) according to claim 8, wherein the active optoelectronic component (122) comprises a light source configured to emit light; and wherein the optical component (200a-200h) is disposed with respect to the active optoelectronic component (122) such that the light emitted by the light source passes through the opening defined by the aperture element (206) before passing through the optical substrate (202).

12. A method (400) of fabricating an optical component, the method comprising providing ( 10) an optical substrate configured to be transparent for light in a predefined wavelength range; forming (420) an aperture element and an electrically conductive trace at the same side of the optical substrate, wherein the aperture element is configured to define an opening for the optical element to, during an operation of the optical component, partially block light and partially allow light to pass through the opening, wherein the electrically conductive trace is configured to allow detection of a damaged condition of the optical component by a variation of an electrical parameter of the electrically conductive trace; and coupling (430) an optical element with the optical substrate, wherein the optical element is configured to implement a predefined optical function.

13. The method (400) according to claim 12, wherein forming (420) the aperture element and the electrically conductive trace comprises carrying out a single deposition of a material of the aperture element and the electrically conductive trace through a common mask; or wherein forming (420)the aperture element and the electrically conductive trace comprises carrying out a first deposition of a first material of the aperture elementthrough a first mask, and carrying out a second deposition of a second material of the electrically conductive trace through a second mask.

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