Patent Application
20240393612
The present disclosure relates generally to methods and systems for bonding and aligning optical surfaces.
A mechanical or optical element may contain two or more flat reflective surfaces that should have a specific relative position or angular orientation between them. The manufacturing of such elements may be technically challenging and expensive, particularly in cases where high accuracy is required. There exists an unmet need in the art for easily implementable techniques for bonding and accurately aligning optical elements.
Aspects of the disclosure, according to some embodiments thereof, relate to methods and systems for producing complex prisms by bonding two or more prisms using active alignment. More specifically, but not exclusively, aspects of the disclosure, according to some embodiments thereof, relate to generating complex prism structures with high angular accuracy between components. This is of particular interest for producing refractive complex waveguide structures and for assuring quality thereof.
Thus, according to an aspect of some embodiments, there is provided a system for producing a composite prism having a plurality of planar external surfaces by aligning and bonding two or more prism components along bonding surfaces thereof, the system includes: an infrastructure configured to bring the bonding surfaces of the first prism component and the second prism component into close proximity or contact; a controllably rotatable mechanical axis configured to align at least one first surface of the first prism component and at least one second surface of the second prism component; a light source configured to project at least one collimated incident light beam on the at least one first surface and the at least one second surface; one or more detectors configured to sense light beams reflected from the first and second surfaces; a computational module configured to determining an average actual relative orientation between the at least one first surface and the at least one second surface based on the sensed data and, if a difference between the weighted average actual relative orientation and an intended relative orientation between the at least one first surface and the at least one second surface is below an accuracy threshold, determine a correction angle for the controllably rotatable mechanical axis, wherein one or more of the prism components are transparent or semi-transparent. According to some embodiments, the computational module is further configured to provide instructions to a controller functionally associated with the rotatable mechanical axis to automatically correct the angle between the first and second surfaces.
According to an aspect of some embodiments, there is provided a method for producing a composite prism having a plurality of planar external surfaces by aligning and bonding two or more prism components along bonding surfaces thereof, the method includes the stages of: bringing the bonding surfaces of the first prism component and the second prism component into close proximity or contact; aligning at least one first surface of the first prism component and at least one second surface of the second prism component; projecting at least one collimated incident light beam on the at least one first surface and the at least one second surface; sensing light beams reflected from the at least one first surface and the at least one second surface; based on the sensed data, determining an average actual relative orientation between the at least one first surface and the at least one second surface; and joining, using a controllably rotatable mechanical axis, the first and second prism components along their bonding surfaces if the difference between the weighted average actual relative orientation and an intended relative orientation between the at least one first surface and the at least one second surface is below an accuracy threshold, wherein one or more of the prism components are transparent or semi-transparent.
According to some embodiments, the step of joining may include one or more of bonding, curing, applying pressure, heating and/or mechanically tightening.
According to some embodiments, the method may further include realigning the first and second surfaces if the difference between the actual relative orientation and the intended relative orientation between the first and second surfaces is above the accuracy threshold.
According to some embodiments, the method may further include repeating the stages of aligning the first and second surfaces, projecting the at least one incident light beam, and determining the actual relative orientation between the first and second surfaces if the difference between the actual relative orientation and the intended relative orientation between the first and second surfaces is above the accuracy threshold.
According to some embodiments, an adhesive may be applied between the bonding surfaces prior to the stage of aligning the first and second surfaces, and, if the difference between the actual relative orientation and an intended relative orientation between the first and second surfaces is below the accuracy threshold, the first prism component and the second prism component are cured along the bonding surfaces thereof. The adhesive may be applied between the bonding surfaces prior to the stage of aligning the first and second surfaces, and, if the difference between the actual relative orientation and an intended relative orientation between the first and second surfaces is below the accuracy threshold, the first prism component and the second prism component are cured along the bonding surfaces thereof.
According to some embodiments, the at least one incident light beam may include a first incident light beam and a second incident light beam directed at a first angle and a second angle relative to the first surface and the second surface, respectively. The at least one incident light beam may be monochromatic. According to some embodiments, each of the at least one incident light beam may be a laser beam. According to some embodiments, the at least one incident light beam may be coherent.
According to some embodiments, the light beams reflected from the first surface and the second surface are focused onto a photosensitive surface, and wherein the difference between the actual relative orientation and the intended relative orientation between the first and second surfaces is derived from locations of a first and second spot formed on the photosensitive surface by the light reflected from the first surface and the second surface, respectively. The incident light beams may be generated using an autocollimator and wherein the photosensitive surface is a photosensitive surface of an image sensor of the autocollimator. The incident light beams may be coherent and the difference between the actual relative orientation and the intended relative orientation between the first and second surfaces may be derived from measuring of an interference pattern of the reflected light beams.
According to some embodiments, the first and second surfaces are intended to be contiguous.
According to some embodiments, the first and second surface are intended to be oriented perpendicularly, or substantially perpendicularly, to one another.
According to some embodiments, an angle between the first and second surface is intended to be less than about 20 Deg. The first and second surface is intended to be less than about 10 Deg.
According to some embodiments, the first and second surface are intended to be parallel or substantially parallel to each other.
According to some embodiments, the first and second surfaces are external surfaces. According to some embodiments, at least one of the first surface and the second surface is an internal facet.
According to some embodiments, the at least one second surface may include a plurality of internal facets nominally co-parallel, wherein the projecting of the at least one collimated incident light beam and the sensing of the light beams are separately performed on the first surface and each one of the internal facets.
According to some embodiments, the first prism component and/or the second prism component may include joined sub-prisms defining therebetween an internal facet, and/or the first prism and and/or the second prism components include an embedded internal facet.
According to some embodiments, the first and/or second surfaces are coated with a reflective coating.
According to some embodiments, the second surface is an embedded internal facet, and wherein the method may further include an initial stage of submerging the composite prism in an immersive medium having a refractive index equal the second prism component; and/or the second prism component may include a first sub-prism and a second sub-prism, which are joined, wherein the second surface is an internal facet defined by a boundary between the first sub-prism and the second sub-prism, and wherein the method may further include an initial stage of immersing the composite prism in a medium having a refractive index equal to the first sub-prism.
According to some embodiments, the at least one incident light beam is projected normally to a surface of the immersive medium.
According to some embodiments, the second prism component may include the first sub-prism and the second sub-prism, wherein the at least one incident light beam includes a first incident light beam and a second incident light beam propagated onto the first surface and the second surface, respectively, and wherein the second incident light beam traverses the first sub-prism to reach the second surface.
According to some embodiments, the method may further include determining a relative position of the first prism component with respect to the second prism component.
According to some embodiments, the determination of the relative position of the first prism component with respect to the second prism component is performed using one or more cameras. According to some embodiments, the determination of the relative position of the first prism component with respect to the second prism component is performed using one or more cameras.
According to some embodiments, the first surface of the first prism component and the second surface of the second prism component are intended to be non-parallel, wherein the incident light beam is projected at a substantially perpendicular direction to the first surface of the first prism component, and wherein a mediating optical element is utilized to direct a portion of the incident light beam onto the second surface of the second prism component so as to impinge thereon substantially normally thereto. The mediating optical element is selected from a group consisting of a pentaprism, right-angled prism, a set of mirrors, and a diffracting optical grating or element.
According to some embodiments, the collimated incident light beam is a polarized light.
According to some embodiments, the method may further include placing between the bonding surfaces of the first and the second prisms, two additional sub-prisms and aligning the first surface of the first prism and the second surface of the second prism utilizing the two additional sub-prisms, wherein each of the additional sub-prisms has two non-parallel surfaces defining two different angles, thereby allowing to controllably set an angle between the bonding surfaces of the first and the second prism components.
According to an aspect of some embodiments, there is further provided a system for measuring and/or validating an orientation between two non-parallel surfaces of an optical element, the system includes: an infrastructure configured to position an optical element including a first surface and a second surface, which are set at an angle with respect to one another; a light source configured to project at least one collimated incident light beam having a first and a second sub-beams such that the first sub-beam impinges substantially normally on the first surface and the second sub-beam impinges substantially normally on the second surface following passage through a mediating optical element; one or more detectors configured to sense light reflected from the first surface and light reflected from the second surface following repassage through the mediating optical element; and a computational module configured to determine an actual relative orientation between the first and second surfaces based on the sensed data.
According to an aspect of some embodiments, there is provided a method for measuring and/or validating an orientation between two non-parallel surfaces of an optical element, the method includes: providing an optical element including a first surface and a second surface, which are set at an angle with respect to one another; projecting at least one collimated light beam, including a first sub-beam and a second sub-beam, such that the first sub-beam impinges substantially normally on the first surface and the second sub-beam impinges substantially normally on the second surface following passage through a mediating optical element; sensing light reflected from the first surface and light reflected from the second surface following repassage through the mediating optical element; and based on the sensed data, determining an actual relative orientation between the first surface and the second surface.
According to some embodiments, the angle between the first surface and the second surface is about 90°. According to some embodiments, the angle between the first surface and the second surface is between about 20° and about 90°. According to some embodiments, the angle between the first surface and the second surface is between about 30° and about 70º.
According to some embodiments, the first surface and the second surface are external surfaces.
According to some embodiments, the first surface is an external surface, and the second surface is an internal surface.
According to some embodiments, the optical element may further include a first plurality of internal surfaces, nominally parallel to the first surface, and the method may further include applying the steps of projecting, sensing and determining with respect to each of the first plurality of internal surfaces and the second surface.
According to some embodiments, the method may further include an average actual relative orientation between the second surface and the first surface and the first plurality of internal surfaces.
According to some embodiments, the optical element may further include a second plurality of internal surfaces, nominally parallel to the second surface and wherein the method may further include applying the steps of projecting, sensing and determining with respect to each of the second plurality of internal surfaces and the first surface.
According to some embodiments, the method may further include computing an average actual relative orientation between the second surface and the first surface and the first plurality of internal surfaces.
According to an aspect of some embodiments, there is further provided a system for measuring and/or validating an orientation between two nominally parallel, or nominally close to parallel, and laterally overlapping surfaces of an optical element, the system includes: an infrastructure configured to position an optical element, the optical element includes a first surface and a second surface, which are nominally parallel, or nominally close to parallel, and are laterally overlapping, wherein one of the first surface and the second surface has substantially higher reflectivity than the other; a light source configured to non-simultaneously project an s-polarized collimated light beam and a p-polarized collimated light beam, directed so as to be incident substantially at Brewster's angle relative to the surface having the substantially higher reflectivity, thereby allowing to distinguish light reflected from the first surface from light reflected from the second surface; one or more detectors configured to sense light reflected from the first surface and light reflected from the second surface; and a computational module configured to determine an actual relative orientation between the first surface and the second surface based on the sensed data.
According to an aspect of some embodiments, there is provided a method for measuring and/or validating an orientation between two nominally parallel, or nominally close to parallel, and laterally overlapping surfaces of an optical element, the method includes: providing an optical element including a first surface and a second surface, which are nominally parallel, or nominally close to parallel, and are laterally overlapping, wherein one of the first surface and the second surface has substantially higher reflectivity than the other; non-simultaneously projecting an s-polarized collimated light beam and a p-polarized collimated light beam, directed so as to be incident substantially at Brewster's angle relative to the surface having the substantially higher reflectivity, thereby allowing to distinguish light reflected from the first surface from light reflected from the second surface; sensing light reflected from the first surface and light reflected from the second surface; and based on the sensed data, determining an actual relative orientation between the first surface and the second surface.
According to some embodiments, the first surface is an external surface, and the second surface is an internal surface.
According to some embodiments, the optical element may further include a first plurality of internal surfaces, nominally parallel to the first surface, and wherein the method may further include applying the steps of projecting, sensing and determining with respect to each of the first plurality of internal surfaces and the second surface.
According to some embodiments, the method may further include computing an average actual relative orientation between the second surface and the first surface and the first plurality of internal surfaces.
According to some embodiments, an angle nominally close to parallel is smaller than about 5 arc minutes.
According to an aspect of some embodiments, there is further provided a system for measuring and/or validating an orientation between two nominally parallel, or nominally close to parallel, and laterally overlapping surfaces of an optical element, the system includes: an infrastructure including a wedge prism and a shutter assembly, the infrastructure being configured to place the wedge prism on an external first surface of an optical element which is to be inspected, the optical element further includes an external or internal second surface, which is nominally parallel, or nominally close to parallel to the first surface, and laterally overlapping therewith; a light source configured to project a collimated incident light beam directed at the optical element and the wedge prism; a shutter assembly configured be controllably switched at least between a first state and a second state, in the first state the shutter assembly blocks light from directly impinging on the first surface of the optical element, and in the second state the shutter assembly blocks light from impinging on the wedge prism; one or more light detectors configured to sense light directly reflected from the first surface and light reflected from the second surface following passage through the wedge prism; and a computational module configured to determine an actual angle between the first surface based on first sensed data and second sensed data, the first sensed data being obtained by the one or more light detectors when the shutter assembly is in a first state and the second sensed data being obtained by the one or more light detectors when the shutter assembly is in a second state.
According to an aspect of some embodiments, there is provided a method for measuring and/or validating an orientation between two nominally parallel, or nominally close to parallel, and laterally overlapping surfaces of an optical element, the method includes: providing an optical element including an external first surface and an external or internal second surface, which are nominally parallel, or nominally close to parallel, and are laterally overlapping; placing a wedge prism on the first surface, wherein the wedge prism has the same refractive index as the optical element; projecting a collimated incident light beam on a top surface of the wedge prism, such that the second surface of the optical element and the top surface of the wedge reflect light, while blocking light from being reflected from the first surface; sensing light reflected from the second surface following re-passage through the wedge prism; projecting the collimated incident light beam on the first surface, such first surface reflects light, while blocking light from being reflected from the top surface of the wedge and from the second surface; sensing light reflected from the first surface; and based on the sensed data, determining an actual angle between the first surface and the second surface.
According to some embodiments, an index matched liquid is placed between the wedge prism and the optical element.
According to some embodiments, the method may further include using a shutter assembly to selectively block light from impinging directly on the first surface or from impinging on the top surface of the wedge prism.
According to some embodiments, the second surface is an internal surface.
According to some embodiments, the optical element includes a composite prism. According to some embodiments, the optical element includes a waveguide structure. According to some embodiments, the optical element includes a composite prism and a waveguide structure.
Certain embodiments of the present disclosure may include some, all, or none of the above advantages. One or more other technical advantages may be readily apparent to those skilled in the art from the figures, descriptions, and claims included herein. Moreover, while specific advantages have been enumerated above, various embodiments may include all, some, or none of the enumerated advantages.
Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. In case of conflict, the patent specification, including definitions, governs. As used herein, the indefinite articles “a” and “an” mean “at least one” or “one or more” unless the context clearly dictates otherwise.
Unless specifically stated otherwise, as apparent from the disclosure, it is appreciated that, according to some embodiments, terms such as “processing”, “computing”, “calculating”, “determining”, “estimating”, “assessing”, “gauging” or the like, may refer to the action and/or processes of a computer or computing system, or similar electronic computing device, that manipulate and/or transform data, represented as physical (e.g. electronic) quantities within the computing system's registers and/or memories, into other data similarly represented as physical quantities within the computing system's memories, registers or other such information storage, transmission or display devices.
Embodiments of the present disclosure may include apparatuses for performing the operations herein. The apparatuses may be specially constructed for the desired purposes or may include a general-purpose computer(s) selectively activated or reconfigured by a computer program stored in the computer. Such a computer program may be stored in a computer readable storage medium, such as, but not limited to, any type of disk including floppy disks, optical disks, CD-ROMs, magnetic-optical disks, read-only memories (ROMs), random access memories (RAMs), electrically programmable read-only memories (EPROMs), electrically erasable and programmable read only memories (EEPROMs), magnetic or optical cards, or any other type of media suitable for storing electronic instructions, and capable of being coupled to a computer system bus.
The processes and displays presented herein are not inherently related to any particular computer or other apparatus. Various general-purpose systems may be used with programs in accordance with the teachings herein, or it may prove convenient to construct a more specialized apparatus to perform the desired method(s). The desired structure(s) for a variety of these systems appear from the description below. In addition, embodiments of the present disclosure are not described with reference to any particular programming language. It will be appreciated that a variety of programming languages may be used to implement the teachings of the present disclosure as described herein.
Aspects of the disclosure may be described in the general context of computer-executable instructions, such as program modules, being executed by a computer. Generally, program modules include routines, programs, objects, components, data structures, and so forth, which perform particular tasks or implement particular abstract data types. Disclosed embodiments may also be practiced in distributed computing environments where tasks are performed by remote processing devices that are linked through a communications network. In a distributed computing environment, program modules may be located in both local and remote computer storage media including memory storage devices.
Some embodiments of the disclosure are described herein with reference to the accompanying figures. The description, together with the figures, makes apparent to a person having ordinary skill in the art how some embodiments may be practiced. The figures are for the purpose of illustrative description and no attempt is made to show structural details of an embodiment in more detail than is necessary for a fundamental understanding of the disclosure. For the sake of clarity, some objects depicted in the figures are not drawn to scale. Moreover, two different objects in the same figure may be drawn to different scales. In particular, the scale of some objects may be greatly exaggerated as compared to other objects in the same figure.
In the Figures:
The principles, uses, and implementations of the teachings herein may be better understood with reference to the accompanying description and figures. Upon perusal of the description and figures present herein, one skilled in the art will be able to implement the teachings herein without undue effort or experimentation. In the figures, same reference numerals refer to same parts throughout.
In the description and claims of the application, the words “include” and “have”, and forms thereof, are not limited to members in a list with which the words may be associated.
As used herein, the term “about” may be used to specify a value of a quantity or parameter (e.g. the length of an element) to within a continuous range of values in the neighborhood of (and including) a given (stated) value. According to some embodiments, “about” may specify the value of a parameter to be between 80% and 120% of the given value. For example, the statement “the length of the element is equal to about 1 m” is equivalent to the statement “the length of the element is between 0.8 m and 1.2 m”. According to some embodiments, “about” may specify the value of a parameter to be between 90% and 110% of the given value. According to some embodiments, “about” may specify the value of a parameter to be between 95% and 105% of the given value. In particular, it is to be understood that the terms “about equal” and “equal to about” also cover exact equality.
As used herein, according to some embodiments, the terms “substantially” and “about” may be interchangeable.
For case of description, in some of the figures a three-dimensional cartesian coordinate system is introduced. It is noted that the orientation of the coordinate system relative to a depicted object may vary from one figure to another. Further, the symbol ⊙ may be used to represent an axis pointing “out of the page”, while the symbol ⊗ may be used to represent an axis pointing “into the page”.
In the figures, optional elements and optional stages (in flowcharts) are delineated by a dashed line.
Throughout the description, vectors are represented by lowercase, upright letters in boldface (e.g. v).
Reference is now made to
Complex prism 400 is constructed by bonding two sub-prisms, sub-prism 410 and sub-prism 420. According to this example, it is desired that surface 411 of sub-prism 410 and surface 421 of sub-prism 420 will be oriented at an accurate angle with respect to one another. As demonstrated in
According to some embodiments, the alignment of prisms 410 and 420 may be performed in an iterative process of measurement and correction of the relative orientation between surfaces 411 and 421. According to additional or alternative embodiments, the alignment of prisms 410 and 420 may be performed by measuring the relative orientation in real time, while correcting the relative orientation of the surfaces 411 and 421.
According to some embodiments, measurement of the angle between the two surfaces may be made optically as will be demonstrated in
Alternatively, according to some embodiments, sub-prisms (for example, two, three, four or more) may be placed between two bonding surfaces of two sub-prisms to facilitate active accurate angular alignment in both x-y and y-z planes of two respective surfaces of the two sub-prisms. Reference is now made to
According to some embodiments, each one of complex prism 400′, prism 410′, prism 420′, surface 411′, surface 421′, surface 412′ and surface 422′, may be the same as (e.g., have the same characteristics) complex prism 400, prism 410, prism 420, surface 411, surface 421, surface 412 and surface 422, respectively. According to alternative embodiments, some or all of the following elements: complex prism 400′, prism 410′, prism 420′, surface 411′, surface 421′, surface 412′ and surface 422′, may be different than complex prism 400, prism 410, prism 420, surface 411, surface 421, surface 412 and surface 422.
According to this example, it is desired that external surface 511 of sub-prism 510 and internal surface 523 of sub-prism 520 will be oriented at an accurate angle with respect to one another.
In accordance with some embodiments, sub-prisms 520a and 520b may be made of different materials, and internal surface 523 may be coated with an optical coating. It is noted that since light is refracted when entering a media and since surface 521 is not measured, the absolute angle between surfaces 523 and 511 cannot necessarily be measured accurately according to the method described above for complex prism 400 (
When this is not necessarily the case, in accordance with some embodiments, sub-prism 520 of complex prism 500 (or parts thereof) may be placed in contact with another structure that is made of a media with a refractive index that is matched to that of sub-prism 520 (or at least with sub-prism 520a), where the geometry of the structure is made such that light impinging the surface 521 would enter the index-matched media at normal incidence (or close to normal incidence). For example, the entire complex prism or parts thereof, may be placed inside a tank with an index-matching immersive medium (such as a liquid). In this case, light would not be refracted when entering the media at surface 521, and the accurate absolute angle between surfaces 511 and 523 could be measured.
Two examples of optical setups for measurement of the angle between two desired surfaces (for example, surface 411 and 421, are demonstrated in
As depicted in
The collimated light beam (depicted by arrows) impinges on both surfaces A and B, such that part of the beam is reflected by surface A and another part of the beam is reflected by surface B. The light reflected from surfaces A and B is then focused (e.g., using a lens, such as lens 608a to small spots or lines on a detector such as a camera 610a, thereby converting any angular misorientation to a spatial separation of the light from each surface. In other words, different angles of surfaces A and B results in shifted spots on camera 601a, and the displacement of the two spots indicates their relative angular orientation. According to some embodiments, optical setup 600a may further include shutters 612a and 612b, which are configured to allow controllable blocking of incident light from impinging on surface A or surface B so as to facilitate detecting light from one surface at a time. This may be of particular relevance in embodiments wherein surface A and surface B are nominally parallel—in which case, were shutters 612 not used, the two spots may not be well resolved, and the accuracy of the measurement would be limited.
According to some embodiments, a commercially available autocollimator may also be used.
Alternatively, an optical setup 600b (as depicted in
However, when measuring/validating parallelism between surfaces, it is often difficult to accurately measure small angles, e.g., on the order of few arcseconds using schemes such as described in
In cases where the surfaces to be aligned (or which alignment need be verified) laterally overlap one another (e.g., when one of the surfaces is an external surface and the second surface is an internal surface, normally parallel thereto and located therebelow), it is not possible to block one or the other of the surfaces utilizing a shutter (as in
According to some embodiments, wherein two surfaces are nominally parallel and laterally overlap, to overcome the challenges discussed in the previous paragraph, illumination of the samples with polarized light at Brewster's angle (as depicted in
In another embodiment, the relative angle between two nearly parallel surfaces can be measured, as described in
However, when measuring reflection from two nearly parallel surfaces, the spots from both surfaces will partially overlap, and the accuracy of the measurement will be reduced. Therefore, it is required to separate the signals obtained from each of the two surfaces. This may be addressed, in accordance with some embodiments, by placing a wedge prism on a top surface of the optical element and blocking light that does not go through the wedge prism, such that only a bottom (or internal) surface of the optical element and the top surface of the wedge prism will reflect light, and no light will be reflected from the top surface of the optical element (if an index matched liquid is placed between the wedge prism and the optical element). Since the top surface of the wedge prism and the bottom surface of the optical element are not parallel, their reflected light signals will be distinguishable, thereby the reflection angle of the bottom surface of the optical element can be calculated accurately. Next, the measurement of the top surface of the optical element can be obtained by blocking light from the wedge prism and considering only light reflected from the top surface of the optical element.
As described in
It is noted that, in accordance with some embodiments, rays 1231′ and 1231″ can be differentiated in the detection by physically blocking part of the beam. Therefore, the measurement of the relative angles between 1231′ and 1233, and between 1231′ and 1231″ can be performed separately, if the reflectivity from 1212 is weak as compared to the reflectivity from 1221. If needed (i.e., if 1211 and 1213 are nearly parallel), reflections from surface 1213 can be suppressed by placing an index matched liquid on 1213 that would diffuse the reflected light, or alternatively, reflect it to other non-relevant directions.
In accordance with some embodiments, for example, but not limited to, in cases where the angle between the two surfaces of interest is relatively large, i.e., about 90°, it may be preferable to measure the angle using a mediating optical element. Example of such cases is demonstrated in
Reference is now made to
According to some embodiment, the angle at which mediating optical element 830 folds the light is equal to the nominal angle between surface 825 (to which mediating optical element 830 is attached) and surface 811, as indicated below in greater detail in the discussion regarding
A first part of collimated light beam/laser (depicted by arrows 850) impinges normally on a sample (complex prism 800) at surface 811 and is reflected back to be detected by the detector (light beams are depicted by arrows 850′). A second part of the collimated light beam/laser (depicted by arrows 855) impinges normally on surface 832 of mediating optical element 830, which is placed such that surface 832 is parallel to surface 811. Second part of collimated light beam/laser 855 is transmitted through surface 832, undergoes internal reflection within mediating optical element 830, exits mediating optical element 830 so as to nominally normally impinge on surface 825 and propagates back through optical element 830 to be detected by the detector (light beams are depicted by arrows 855′). Relative angle between surface 811 and surface 825 may be measured by light according to the above presented methods (for example as described in
According to some embodiments, in case a sample has two parallel reflective surfaces, for example, when surfaces 811 and surface 813 of sub-prism 810 are parallel and surface 825 is nominally perpendicular thereto, the measurement accuracy may be increased by performing an additional measurement with the sample flipped such that surface 811 replaces surface 813 and surface 832 stays in its place (parallel to surface 813). Finally, the relative angle of the mediating optical element may be calculated as the average of the absolute value of these two measurements.
Occasionally, one (or more) of the surfaces of the mediating optical element may reflect light into the measuring system and contaminate the recorded image with a deleterious reflection. To overcome this effect, in accordance with some embodiments, the deleterious reflection may be suppressed by applying light absorbing material on the undesirably reflective surface (e.g., painting the surface with light absorbing paint), grinding the surface or covering it with a refractive index matched material that scatters light, e.g., grease or wax. According to additional or alternative embodiments, the deleterious reflection may be distinguished from the desired reflection by coating the surfaces with spectrally sensitive optical coatings. In this manner, the two surfaces will reflect different optical spectra.
Reference is now made to
Notice there are two possible optical paths: one where the incoming light 860 is first reflected by surface 813 and then by surface 826 (depicted by grey arrows 815), and another one where the incoming light 860 is first reflected by surface 825 and only then by surface 813 (depicted by grey arrows 815). If the surfaces 813 and 826 are not fully perpendicular, rays 860 and 860′ will not be parallel, and the rays 860′ originating from the first optical path would be different than those originating from the second optical path. Each path will be tilted in opposite directions, and the angular distance between these two light peaks will indicate the relative orientation of the surfaces.
Similarly, the configuration of also
The figures disclosed hereinabove, in accordance with some embodiments, are typically (not necessarily) related to cases where the required angle between two surfaces (to be measured/validated or aligned) is either small, e.g., smaller than about 10 deg, or large, e.g., larger than about 80 deg. In accordance with some embodiments, in cases where the required angle between the two surfaces is intermediate (e.g., between about 10 deg and about 80 deg) the relative angle may be calculated by a custom made mediating optical element, as presented, for example, in
Light from an autocollimator 1901 is directed to impinge, normally, on surface 1972 of optical element 1970, positioned parallel to surface 1911 of sub-prism 1910, such that the transmitted rays through surface 1974 impinge surface 1911 (light beams are depicted by arrows 1980), and on surface 1925 of sub-prism 1920 (light beams are depicted by arrows 1985). Light that is reflected back from surface 925 of sub-prism 1920 (light beams are depicted by arrows 1985′) is detected by the detector. Light that is transmitted into optical element 1970, exits therefrom so to nominally normally impinge on surface 1911 of sub-prism 1910 and propagates back through optical element 1970 to be detected by the detector (light beams are depicted by arrows 1980′). The distance between the two light peaks obtained on the detector will thus indicate the relative orientation between surfaces 1911 and 1925.
It is noted that optical element 1970 is shown herein as a prism but may be any other optical element that is configured to fold light at a desired predetermined angle.
According to some additional or alternative embodiments, it is often required to control and/or to validate the relative positioning of a sub prism relative to other (one or more) sub-prism(s) in a complex prism structure. This can be required in addition to or instead of controlling, adjusting and/or validating the angular orientation between two or more prisms that are then bonded together (or surfaces thereof. Examples of such cases are described in
According to some embodiments, there is provided a method and a system for controlling the relative position between two or more sub-prisms according to external surface(s) of a complex prism, as shown in
According to some embodiments, there is provided a method and a system for controlling the relative position between two or more sub-prisms according to external surface(s) and internal facet(s) of the complex prism, as shown for example in
According to some embodiments, there is provided a method and a system for controlling both the relative position and orientation of two or more sub-prisms (typically, but not limited to, simultaneously). The relative position between two or more sub-prisms may be set according to external surface(s) of the complex prism, as shown, for example, in
According to some embodiments, as in the case of controlling the angular orientation of the sub-prisms, controlling the relative position between the prisms may be made with an iterative procedure of measurement and correction of the relative position; or according to alternative embodiments, by measuring the relative position in real time while correcting the relative position.
According to some embodiments, the position measurement may be carried out optically, for example by using two cameras with optical imaging systems, such that the positioning can be followed along opposite sides of the prisms such that each camera has visibility to allow determining displacements along both x and y axes. It is noted that in some cases a single camera may also be used for this purpose. Reference is now made to
According to alternative embodiments, one camera may be used, together with an accurate measurement of the relative angular orientation between sub-prisms 1110 and 1120 (for example, between surface 1111 of sub-prism 1110 and surface 1121 of sub-prism 1120, as discussed hereinabove.
As discussed above in accordance with some embodiments, the methods and system disclosed herein are suitable not only of active alignment of prisms and sub-prisms but also to (passive) measurements of orientation and position of internal and/or external surfaces, specifically in the context of quality analysis of individual optical waveguide structures.
Reference is now made to
Reference is now made to
Reference is now made to
Throughout the description, internal, surfaces (such as a flat boundary between two parts of a three-dimensional element or an internal flat layer of material incorporated into a three-dimensional element) of three-dimensional elements are referred to as “internal facets”.
As used herein, in accordance with some embodiments, the terms “facet”, “internal facet” and “internal surface” are used interchangeably. As used herein, in accordance with some embodiments, the terms “facet”, “internal facet”, “internal surface”, “external surface” and “surface” refer to flat “facet”, “internal facet”, “internal surface”, “external surface” and “surface”.
As used herein, in accordance with some embodiments, the terms “measuring” and “sensing” are used interchangeably. Similarly, the terms “sensed data” and “measurement data” (or “measured data”) are used interchangeably.
As used herein, in accordance with some embodiments, the terms “complex” and “composite”, with respect to an optical element, such as a prism or a waveguide structure, are used interchangeably and may include optical element composed of two or more sub-optical elements and/or may include one or more internal facets (for example, about 10-20, 10-50, 50-100 or more). The one or more internal facets may be co-parallel.
In accordance with some embodiments, the term “bonded” or “bonding” as used herein should be understood to mean attached or attaching with an optical cement or glue, or any other suitable adhesive.
As used herein, in accordance with some embodiments, the terms “optical waveguide structure”, “waveguide structure”, “refractive complex waveguide structure” and “light-guide optical element (LOE)”, are used interchangeably.
As used herein, an object may be said to “nominally” exhibit (i.e., be characterized by) a property, such as an angle between flat surfaces of a sample (such as an optical element), when the object is intended by design and fabrication to exhibit the property but, in practice, due to manufacturing tolerances, the property may actually be imperfectly exhibited.
As used herein, in accordance with some embodiments, the term “laterally overlap” or “laterally overlapping” with respect to two surfaces, may refer to full or partial horizontal overlap, wherein it is understood that the two surfaces are vertically separated.
As used herein, the terms “measuring” and “sensing” are used interchangeably. Similarly, the terms “sensed data” and “measured data” are used interchangeably.
It is appreciated that certain features of the disclosure, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the disclosure, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable sub-combination or as suitable in any other described embodiment of the disclosure. No feature described in the context of an embodiment is to be considered an essential feature of that embodiment, unless explicitly specified as such.
Although stages of methods according to some embodiments may be described in a specific sequence, methods of the disclosure may include some or all of the described stages carried out and/or occurring in a different order. A method of the disclosure may include a few of the stages described or all of the stages described. No particular stage in a disclosed method is to be considered an essential stage of that method, unless explicitly specified as such.
Although the disclosure is described in conjunction with specific embodiments thereof, it is evident that numerous alternatives, modifications, and variations that are apparent to those skilled in the art may exist. Accordingly, the disclosure embraces all such alternatives, modifications, and variations that fall within the scope of the appended claims. It is to be understood that the disclosure is not necessarily limited in its application to the details of construction and the arrangement of the components and/or methods set forth herein. Other embodiments may be practiced, and an embodiment may be carried out in various ways.
The phraseology and terminology employed herein are for descriptive purpose and should not be regarded as limiting. Citation or identification of any reference in this application shall not be construed as an admission that such reference is available as prior art to the disclosure. Section headings are used herein to case understanding of the specification and should not be construed as necessarily limiting.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/IL2022/050931 | 8/28/2022 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 63238250 | Aug 2021 | US | |
| 63284661 | Dec 2021 | US |
