Low profile CPO connector and receptacle with v-groove

Abstract

An FAU alignment system includes an FAU assembly / connector, an alignment assembly, a receptacle or receptacle assembly, a spring element, and a photonic integrated circuit. The FAU assembly / connector includes an FAU cover, an upper FAU element, a stepped lower FAU element, a microlens array, a prism, and an FAU alignment element with v-grooves for rods or pins. The alignment assembly includes a cover and a base coupled by a hinged engagement. The cover has a front cover portion with a cantilevered cover element, prongs, and cover arms with slots formed by flexible portions, and a rear cover portion with a rear bridge and rear cover arms having inwardly extending protrusions and angled or arc-shaped surfaces. The base supports a receptacle or receptacle assembly having a stop element and a plate element providing engagement and alignment surfaces for the FAU assembly / connector.

Description

Attorney Docket No.: HI24-073PCTLOW PROFILE CPO CONNECTOR AND RECEPTACLE WITH V-GROOVERELATED APPLICATIONS

[0001] This application claims the benefit of priority of U.S. Provisional Application Serial No. 63 / 725,039 filed on November 26, 2024, the content of which is relied upon and incorporated herein by reference in its entirety.BACKGROUND

[0002] The present disclosure generally relates to low-profile connectors and receptacles for co-packaged optics applications and related methods and systems.

[0003] The field of Silicon Photonics (SiP) has been in development for several years and some products have been commercialized and more are under active development. In SiP silicon is used as the optical medium, primarily in the near infrared (NIR) wavelength band around wavelengths of 1.31 pm and 1.55 pm, which are used in telecommunications.

[0004] Some advantages of SiP are the possibilities to use existing semiconductor fabrication methods and infrastructure and the integration of electronics and photonics into a single chip as photonic integrated circuits (PIC) or at least into components that work closely together.

[0005] One of the problems that has not yet been finally solved is a method of injecting or extracting light into / out of the SiP chips. In telecommunications, light is usually transported in fibers, which now have to be coupled to the SiP PICs. Here, three methods can be distinguished. The first, edge coupling, during which waveguides of the SiP chip end are interfaced with at the edge (side) of the SiP chip. The second grating coupling, during which the PICs use grating couplers as an interface, where the light path is close to perpendicular to the surface of the chip. Grating couplers can be located anywhere on the chip’s surface. And the third is evanescent coupling. For evanescent coupling, the waveguide in the silicon is brought into close proximity with a glass waveguide so that the light can couple evanescently from the silicon to the glass and vice versa.

[0006] One of the difficulties with coupling light to SiP PICs is the difference in mode field diameters. Single mode fibers have a mode field diameter of about 10 pm, whileAttorney Docket No.: HI24-073PCT modes in silicon waveguides may be of submicron dimensions because of the large refractive index of silicon (about 3.5), which leads to high losses if the fibers are coupled directly to the SiP waveguides. To reduce these losses, mode converters are required to scale the modes of the SiP to the size of the fiber modes.

[0007] While grating couplers can be designed such that they easily couple to single mode fibers, they have a limited bandwidth, so that they cannot support many different wavelengths (e.g., for WDM applications). Also, the fiber orientation perpendicular to the surface of the chip poses limits on the geometry / arrangements, in which these chips may be used.

[0008] Edge couplers require separate mode field converters to be able to couple to fibers. These may be realized in the silicon, as an additional interposer chip, where the conversion is realized through changing the waveguide size along the length, or through imaging optics.

[0009] With the evanescent coupling, the mode field conversion can already be built into the geometry of the glass waveguides, to which fibers may then directly be coupled.

[0010] For these reasons, among others, there is a need for improved systems, assemblies, connectors, receptacles, etc. for co-packaged optics applications.SUMMARY

[0011] Disclosed herein are various embodiments of assemblies, connectors and receptacles for co-packaged optics, including related methods and systems.

[0012] One aspect of the disclosure relates to an FAU alignment system including an FAU assembly / connector, an alignment assembly, a receptacle or receptacle assembly, a spring element, and a photonic integrated circuit. The FAU assembly / connector includes an FAU cover, an upper FAU element, a lower FAU element having a stepped configuration with first and second lower FAU portions, a microlens array, a prism, and an FAU alignment element. The FAU cover functions as an FAU lid used to protect elements of the FAU assembly / connector and can be configured to transfer force from a hinged lid of the alignment system to the FAU assembly / connector while accommodating deflection and minimizing impact on an optical path. The FAU cover, the upper FAU element, and the lower FAU element can have substantially the same width, while the FAU alignmentAttorney Docket No.: HI24-073PCT element has a greater width for alignment purposes. The FAU alignment element includes v-grooves configured for positioning alignment elements such as rods or pins.

[0013] According to another aspect of the disclosure, alignment assembly includes a cover and a base coupled by a hinged engagement and is configured for coupling with the FAU assembly / connector and with a receptacle. The cover includes a front cover portion, a rear cover portion, and cover arms with slots formed by flexible portions connecting the front and rear cover portions. The front cover portion includes a cantilevered cover element extending between prongs via curved corners. Each prong extends past the cover arms and includes a prong tip extending toward the rear cover portion. The rear cover portion includes a rear bridge extending between the cover arms and rear cover arms having inwardly extending protrusions and angled or arc-shaped surfaces shaped to facilitate coupling of the rear cover arms with the base. The flexible portions of the cover arms are configured to move upwardly and bend, allowing the cover arms and rear prongs to engage and disengage with alignment features or elements of the base and the receptacle or receptacle assembly, and to be cantilevered to calibrate forces on an FAU alignment part.

[0014] Another aspect of the disclosure relates to a base, which includes a rear base wall having protrusion receiving openings, base sidewalls, a laterally extending front base section, and a downwardly extending front base wall. The rear base wall includes an upper base wall section spanning between the base sidewalls and lower base wall steps aligned with or positioned above the base sidewalls so that a u-shaped opening is defined between the lower base wall steps and a lowermost surface of the upper base wall section. The lower base wall steps include upper step surfaces on which rear cover arms bias when positioned on the upper step surfaces and can extend past an overall length of the upper base wall section. The lower base wall steps are configured such that a lowermost surface of each lower base wall section is laterally aligned with a lowermost surface of the receptacle. The front base section includes a cantilevered lip having a chamfer extending past the front base wall, and the front base wall includes a front base wall extension extending past lowermost surfaces of the base sidewalls and configured to abut against the photonic integrated circuit upon assembly of the FAU alignment system.

[0015] Another aspect relates to a receptacle positioned and partially contained within the base and includes a stop element and a plate element integrally connected to the stop element. The stop element has engagement surfaces configured to mate with the FAUAttorney Docket No.: HI24-073PCT assembly / connector, including an angled stop surface, a substantially vertical stop surface, side stop surfaces, and a substantially horizontal stop surface. The plate element includes alignment surfaces including substantially vertical first and second plate surfaces, side plate surfaces, a top plate surface, and a bottom plate surface, with the top plate surface configured for positioning against a bottommost surface of the FAU alignment element. In another configuration, a receptacle assembly includes separate components: a stop element and a plate element. The stop element has engagement surfaces configured to mate with the FAU alignment element and the base and is positioned between the plate element and an interior surface of the front base section. The stop element can have an angled stop surface, a substantially vertical stop surface, side stop surfaces, a substantially horizontal stop surface, and a bottom surface, and the plate element can include substantially vertical first and second plate surfaces, side plate surfaces, a top plate surface, and a bottom plate surface, with the top plate surface configured for positioning against a bottommost surface of the FAU alignment element.

[0016] Another aspect relates to a spring element, which can be included in the alignment assembly to facilitate alignment of at least a portion of the FAU assembly / connector within the alignment assembly. The spring element is preferably thin and manufactured from a springy material having sufficient spring characteristics and includes a spring body having a lower body portion coupled to spring arms with a recessed area defined therebetween. Upon assembly, the spring element is positioned between the lower FAU element and the front base section of the front base wall and adjacent to the FAU alignment element. Alternatively, a spring system comprising a leaf spring can be used.

[0017] The disclosure further provides additional FAU alignment systems having different covers, bases, and stop elements. In one cover configuration, cover arms include L-shaped slots formed by flexible portions that allow the cover arms to move upwardly and bend. In another cover configuration, the cover arms include substantially horizontal slots formed by flexible portions having curved ends and rear prongs, with a gap configured between the curved ends and the rear prongs. Arrows can illustrate the flexible nature of the flexible portions of the cover arms to move upwardly and bend so that the cover arms and rear prongs engage and disengage with alignment features or elements of the alignment assembly and can be cantilevered to calibrate forces on an FAU alignment part.Attorney Docket No.: HI24-073PCT

[0018] Additional FAU-stop element assemblies are also provided. Each FAU-stop element assembly is coupled to an upper FAU element and a lower FAU element. In some examples, an FAU alignment element includes an upwardly extending alignment portion and an FAU alignment body portion integrally coupled to the alignment portion. A stop element can include an upwardly extending stop portion and a plate portion integrally coupled to the stop portion or can be configured as a rectangular cuboid. Together, the FAU assembly / connector, the alignment assembly, the receptacle or receptacle assembly, and the spring element provide alignment and coupling of the FAU assembly / connector with respect to the photonic integrated circuit while maintaining an optical path between the FAU assembly / connector and the photonic integrated circuit.

[0019] According to yet another aspect of the disclosure, a fiber array unit (FAU) to photonic integrated circuit (PIC) alignment method includes the steps of providing an alignment part that is wider than the FAU (or width-wise extensions of the FAU), providing a clamping surface for a receptacle to retain the FAU. The method and the associated assembly allows for a low-profile assembly to minimize the stack height above the PIC. In preferred configurations, the overall stack height is about 2.5 mm high.

[0020] Additional features and advantages will be set forth in the detailed description which follows, and in part will be readily apparent to those skilled in the art from that description or recognized by practicing the embodiments as described herein, including the detailed description which follows, the claims, as well as the appended drawings.

[0021] It is to be understood that both the foregoing general description and the following detailed description are merely exemplary, and are intended to provide an overview or framework to understanding the nature and character of the claims. The accompanying drawings are included to provide a further understanding, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments, and together with the description serve to explain principles and operation of the various embodiments.BRIEF DESCRIPTION OF THE DRAWINGS

[0022] FIGs. 1 and 2 illustrate a partially exploded isometric view of an FAU alignment system, including an FAU assembly / connector and an alignment assembly in accordance with embodiments disclosed herein;Attorney Docket No.: HI24-073PCT

[0023] FIG. 3 is a partial cross-sectional view of an FAU alignment system in accordance with embodiments disclosed herein;

[0024] FIG. 4 is an exemplary FAU assembly in accordance with embodiments disclosed herein;

[0025] FIG. 5 is an isometric view of a receptacle for co-packaged optics in accordance with embodiments disclosed herein;

[0026] FIG. 6 is an alignment assembly in accordance with embodiments disclosed herein;

[0027] FIG. 7 is an isometric view of a cover embodiment included in an alignment assembly in accordance with embodiments disclosed herein;

[0028] FIG. 8 is an isometric view of a cover embodiment included in an alignment assembly in accordance with embodiments disclosed herein;

[0029] FIG. 9 illustrates an FAU alignment system, including an FAU assembly and an alignment assembly in accordance with embodiments disclosed herein; and

[0030] FIGs 10 A, 10B and 10C illustrate possible stop block configurations, which can be included in an FAU alignment system in accordance with embodiments disclosed herein.

[0031] The figures are not necessarily to scale. Like numbers used in the figures may be used to refer to like components. However, it will be understood that the use of a number to refer to a component in a given figure is not intended to limit the component in another figure labeled with the same number.DETAILED DESCRIPTION

[0032] Various exemplary embodiments of the disclosure will now be described with particular reference to the drawings. Exemplary embodiments of the present disclosure may take on various modifications and alterations without departing from the spirit and scope of the disclosure. Accordingly, it is to be understood that the embodiments of the present disclosure are not to be limited to the following described exemplary embodiments, but are to be controlled by the features and limitations set forth in the claims and any equivalents thereof.Attomey Docket No.: HI24-073PCT

[0033] Unless otherwise indicated, all numbers expressing feature sizes, amounts, and physical properties used in the specification and claims are to be understood as being modified in all instances by the term “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth in the foregoing specification and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by those skilled in the art utilizing the teachings disclosed herein.

[0034] As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” encompass embodiments having plural referents, unless the content clearly dictates otherwise. As used in this specification and the appended claims, the term “or” is generally employed in its sense including “and / or” unless the content clearly dictates otherwise.

[0035] Spatially related terms, including but not limited to, “lower,” “upper,” “beneath,” “below,” “above,” and “on top,” if used herein, are utilized for ease of description to describe spatial relationships of an element(s) to another. Such spatially related terms encompass different orientations of the device in use or operation in addition to the particular orientations depicted in the figures and described herein. For example, if an object depicted in the figures is turned over or flipped over, portions previously described as below or beneath other elements would then be above those other elements.

[0036] Cartesian coordinates are used in some of the Figures for reference and are not intended to be limiting as to direction or orientation.

[0037] For purposes of description herein, the terms “upper,” “lower,” “right,” “left,” “rear,” “front,” “vertical,” “horizontal,” “top,” “bottom,” “side,” and derivatives thereof, shall relate to the disclosure as oriented with respect to the Cartesian coordinates in the corresponding Figure, unless stated otherwise. However, it is to be understood that the disclosure may assume various alternative orientations, except where expressly specified to the contrary.

[0038] For the purposes of describing and defining the subject matter of the disclosure it is noted that the terms “substantially” and “generally” may be utilized herein to represent the inherent degree of uncertainty that may be attributed to any quantitative comparison, value, measurement, or other representation.Attorney Docket No.: HI24-073PCT

[0039] FIGs. 1 and 2 illustrate a partially exploded view of an FAU alignment system 100, including an FAU assembly / connector 200, an alignment assembly 300, a receptacle 400, a spring element 500, and a PIC. FIG. 3 is a cross-sectional view of the alignment system 100 shown in FIGs. 1 and 2, illustrating the alignment assembly 300 with the alignment assembly cover 310 in a closed position. FIG. 3 also schematically illustrates a directional element D indicate an optical path.

[0040] Referring particularly to FIGs. 1, 2, and 4, one embodiment of the FAU assembly / connector 200 includes an FAU cover 210, an upper FAU element 220, a lower FAU element 230, a microlens array MLA, a prism P, and an FAU alignment element 240. The FAU cover 210 is commonly known as an FAU lid used to protect below elements of the FAU assembly / connector. In some embodiments, the FAU cover 210 may be configured as a compliant pad such that it is capable of transferring the force of a hinged lid (of the alignment system, for example) to the FAU assembly / connector. In such embodiments, the FAU cover 210 thus can provide for further alignment of the FAU assembly / connector aligned to a receptacle, as will be further described. In such embodiments, the desired force can be about 100 gf. Such compliant pads are typically used to as heat transfer elements in electronics and are suitable for the high temperatures seen in circuit boards. They are made from compliant materials, and are available in different thicknesses and stiffnesses to allow tuning of compressive forces. The compliant pad is preferably configured to have enough resilience to accommodate deflection, and minimize impact on optical path. Alternatively, a spring system, comprising a leaf spring, for example, could be used.

[0041] The upper FAU element 220 includes a series of centrally-located v-grooves 222 disposed therein for holding one or more glass fibers F, as particularly shown in FIGs. 1 and 2. The lower FAU element 230 has a stepped configuration includes a first lower FAU portion 232, and a second lower FAU portion 234. The second lower FAU portion 234 has a smaller overall height compared to the first lower FAU portion 232. Each of the FAU cover 210, the upper FAU element 220, and the lower FAU element 230 have substantially the same width. In comparison, the FAU alignment element 240 has an overall width that is wider than the FAU cover 210, the upper FAU element 220, the lower FAU element for alignment purposes, as will be further described with respect to the assembly of the FAU assembly / connector 200 with the FAU alignment assembly 300. The FAU alignment element 240 also includes v-grooves 242a, 242b, which may be used for positioning ofAttorney Docket No.: HI24-073PCT alignment elements such as rods or pins 250a, 250b, for example. FIG. 4 shows an exemplary FAU assembly 200 in further detail. Exemplary FAUs are shown and described, inter alia, in US Patent Nos. 10,942,316, 11,194,107, 11,586,000, 11,567,285, and 11,415,753, which are incorporated herein by reference.

[0042] Referring particularly to FIGs. 1 and 2, the alignment system 100 is shown including the alignment assembly 300 and the receptacle 400 coupled to a portion of a photonic integrated circuit (PIC). Both the alignment assembly 300 and the receptacle 400 are also configured for coupling with the FAU assembly / connector 200. In this embodiment of the alignment system 100, the alignment assembly 300 includes a cover 310 and a base 350 coupled to the cover 310 by a hinged engagement. The cover 310 includes a front cover portion 320, a rear cover portion 330, and cover arms 314a, 314b with L-shaped slots 315a, 315b defined therein, connecting the front and rear cover portions 320, 330. Each L-shaped slot is formed by a flexible portion 313a, 313b. The front cover portion 320 includes a cantilevered cover element 322, and a plurality of prongs 340a, 340b extending from a bridge portion 316 of the cantilevered cover element 322. The cantilevered cover element 322 extends between prongs 340a, 340b via curved comers 318a, 318b. Each prong 340a, 340b has a length that extends past cover arms 314a, 314b and includes a prong tip 342a, 342b that extends toward the rear cover portion 330. The rear cover portion 330 is coupled to the base 350, preferably using a mechanical attachment method. To achieve coupling to the base 350, the rear cover portion includes a rear bridge 332, extending between cover arms 314a, 314b, and rear cover arms 334a, 344b, having inwardly extending protrusions 336a, 336b. The rear cover arms 334a, 344b also include angled surfaces 337a, 337b, 338a, 338b, which are shaped to facilitate coupling of the rear cover arms 334a, 344b with the base 350, as shown particularly in FIGs. 1, 2, and 6.

[0043] Referring particularly to FIG. 5, the base 350 is shown, having a receptacle 400 positioned therein. Both the base 350 and the receptacle 400 include various features and elements that facilitate alignment and coupling of the FAU assembly / connector 200 in an alignment system. In some embodiments, the base 350 includes a rear base wall 351, having protrusion receiving openings 352a, 352b defined therein, base sidewalls 360a, 360b, a laterally extending front base section 370, and a downwardly extending front base wall 380. The rear base wall 351 includes an upper base wall section 354, and lower base wall steps 356a, 356b. The upper base wall section 354 is configured to span between base sidewallsAttorney Docket No.: HI24-073PCT360a, 360b, while the lower base wall steps 356a, 356b are aligned with the base sidewalls 360a, 360b such that there is a u-shaped opening 359 bound by the lower base wall steps 356a, 356b and a lowermost surface 358 of the upper base wall section 354. Each lower base wall step 356a, 356b is configured to have an upper step surface 357a, 357b configured such that rear covers arms 334a, 344b bias when positioned on the upper step surface 357a, 357b, as particularly shown in FIGs. 1 and 2. Moreover, the lower base wall steps 356a, 356b extend such that a lowermost surface of each lower base wall section is configured for lateral alignment with the lowermost surface of the receptacle 400. The lower base wall steps 356a, 356b are also configured to extend a distance past the overall length of the upper base wall section 354, as particularly shown in FIG. 5.

[0044] Still referring to FIG. 5, the lower base wall steps 356a, 356b are integrally coupled to base sidewalls 360a, 360b. Each base sidewall 360a, 360b has a base sidewall length that extends from its respective lower base wall step 356a, 356b to integrally couple with the laterally extending front base section 370, and the downwardly extending front base wall 380. Each base sidewall 360a, 360b also includes a contoured sidewall portion 362a, 362b and sidewall arms 364a, 364b. Each contoured sidewall portion 362a, 362b has a stepped configuration, which acts as an alignment feature for the FAU assembly / connector 200.

[0045] The laterally extending front base section 370, and the downwardly extending front base wall 380 are both coupled to base sidewalls 360a, 360b. The laterally extending front base section 370 includes cantilevered lip 372, having a chamfer 374, which extends past the front base wall 380. The downwardly extending front base wall 380 includes a front base wall extension 382 that extends past the lowermost surfaces of the base sidewalls 360a, 360b. As particularly shown in FIGs. 1, 2, and 3, the front base wall extension 382 is configured to abut against the PIC upon assembly of the alignment system 100.

[0046] The receptacle 400 is configured for positioned and partial containment within the base 350, as particularly shown in FIGs. 2, 3, 5, and 6. The receptacle 400 includes a stop element 410 and a plate element 420 integrally connected to the stop element 410. In preferred configurations, the stop element 410 has a plurality of engagement surfaces configured to mate with the FAU assembly / connector 200, as particularly shown in FIG. 3. The stop element can be configured in various ways. Referring to FIGs. 2, 5, and 6, the stop element 410 is centrally located with respect to the plate element, having an overall stopAttorney Docket No.: HI24-073PCT element length which is less than the overall plate element length. In this configuration of the receptacle 400, the stop element 410 has an angled stop surface 412, a substantially vertical stop surface 414, side stop surfaces 416a, 416b, and a substantially horizontal stop surface 418. The plate element 420 includes a plurality of alignment surfaces as well, including substantially vertical first and second plate surfaces 422, 424, side plate surfaces 426a, 426b, a top plate surface 428, and a bottom plate surface 429. The top plate surface 428 is configured for positioning against a bottommost surface of the FAU alignment element 240, as particularly shown in FIG. 3.

[0047] As shown in FIGs. 1, 2, 3, and 6, a spring element 500 may also be included in the alignment assembly 300 to further facilitate alignment of at least a portion of the FAU assembly / connector within the alignment assembly 300. The embodiment of the spring element 500 is preferably thin and manufactured from a springy material, having sufficient spring characteristics. Referring particularly to FIG. 6, the spring element includes a spring body 510 having a lower body portion 512 coupled to two spring arms 514a, 514b having a recessed area 516 therebetween. Upon assembly, the spring element 500 is configured to be positioned between the lower FAU element 230 and the front base section 370 of front base wall 380 and adjacent to the FAU alignment element 240, as particularly shown in FIG. 3.

[0048] FIG. 7 illustrates another cover embodiment, which can be included in an alignment assembly. The cover 310A includes a front cover portion 320’, a rear cover portion 330’, and cover arms 314a’, 314b’ with L-shaped slots 315a’, 315b’ defined therein, connecting the front and rear cover portions 320’, 330’. Each L-shaped slot is formed by a flexible portion 313a’, 313b’. The front cover portion 320’ includes a cantilevered cover element 322’, and a plurality of prongs 340a’, 340b’ extending from a bridge portion 316’ of the cantilevered cover element 322’. The cantilevered cover element 322’ extends between prongs 340a’, 340b’ via curved comers 318a’, 318b’. Each prong 340a’, 340b’ has a length that extends past cover arms 314a’, 314b’ and includes a prong tip 342a’, 342b’ that extends toward the rear cover portion 330’. The rear cover portion 330’ is coupled to the base 350’, preferably using a mechanical attachment method. To achieve coupling to the base 350’, the rear cover portion includes a rear bridge 332’, extending between cover arms 314a’, 314b’, and rear cover arms 334a’, 344b’, having inwardly extending protrusions 336a’, 336b’. The rear cover arms 334a’, 344b’ also include an arc-shaped surface 338a’, 338b’, shaped to facilitate coupling of the rear cover arms 334a’, 344b’ with the base 350.’ The arrows shown in FIG. 7Attorney Docket No.: HI24-073PCT further illustrate the flexible nature of portions 313a’, 313b’ of the cover arms 314a’, 314b’ to move upwardly and bend. Here, the cover arms 314a’, 314b’ can thus be configured to move as needed to allow the cover arms 314a’, 314b’ to bend, engage and disengage with other alignment features or elements included in an alignment assembly. The movement of the cover arms 314a, 314b of the first cover embodiment, using L-shaped slots 315a, 315b can also occur.

[0049] FIG. 8 illustrates yet another cover embodiment, which can be included in an alignment assembly. Here, the cover 310B includes a front cover portion 320”, a rear cover portion 330”, and cover arms 314a”, 314b” with a substantially horizontal slots 315a”, 315b” defined therein, connecting the front and rear cover portions 320”, 330”. Each slot is formed by flexible portions 317a”, 317b”, 319a”, 319b”, having bumped ends 321a”, 321b”, 323a”, 323b” with a gap 325a”, 325b” therebetween. Similar to the first and second cover embodiments, the front cover portion 320” includes a cantilevered cover element 322”, and a plurality of prongs 340a”, 340b” extending from a bridge portion 316” of the cantilevered cover element 322”. The cantilevered cover element 322” extends between prongs 340a”, 340b” via curved comers 318a”, 318b”. Each prong 340a”, 340b” has a length that extends past cover arms 314a”, 314b” and includes a prong tip 342a”, 342b” that extends toward the rear cover portion 330”. The rear cover portion 330” is coupled to the base 350”, preferably using a mechanical attachment method. To achieve coupling to the base 350”, the rear cover portion includes a rear bridge 332”, extending between cover arms 314a”, 314b”, and rear cover arms 334a”, 344b”, having inwardly extending protrusions 336a”, 336b”. The rear cover arms 334a”, 344b” also include an arc-shaped surface 338a”, 338b”, shaped to facilitate coupling of the rear cover arms 334a”, 344b” with the base 350”. The arrows shown in FIG. 8 also illustrate the flexible nature of flexible portions 317a”, 317b”, 319a”, 319b” of the cover arms 314a”, 314b” to move upwardly and bend. Thus, the cover arms 314a”, 314b” can be configured to move as needed to allow for engagement and disengagement with other alignment features or elements included in an alignment assembly. Moreover, the flexible portions 317a”, 317b”, 319a”, 319b” of the cover arms 314a”, 314b can be cantilevered to calibrate forces on an FAU alignment part.

[0050] FIG. 9 illustrates another embodiment of an FAU alignment system 100C, including the FAU assembly 200 and an alignment assembly 300C, having different embodiments of a cover 310C, a base 350C, and stop elements. Various elements on oneAttorney Docket No.: HI24-073PCT side of the FAU assembly 200 and an alignment assembly 300C are not shown, but are referred to herein and should be construed to mirror the respective element on the opposite side of the cover 310C and the base 350C. In this embodiment, the cover 310C includes a front cover portion 320”’, a rear cover portion 330’” and cover arms 314a’”, 314b’” with substantially horizontal slots 315a’”, 315b’” defined therein, connecting the front and rear cover portions 320’”, 330’”. Each slot is formed by flexible portions 317a’”, 317b’”, having curved ends 321a’”, 321b’”, and rear prongs 329a’”, 329b’”. A gap 325a’”, 325b’” is configured between the curved ends 321a’”, 321b’”, and rear prongs 329’”.

[0051] Similar to the other cover embodiments, the front cover portion 320’” includes a cantilevered cover element 322’”, and a plurality of prongs 340a’”, 340b’” extending from a bridge portion 316’” of the cantilevered cover element 322’”. The cantilevered cover element 322’” extends between prongs 340a’”, 340b’” via curved comers 318a’”, 318b’”. Each prong 340a’”, 340b’” has a length that extends past cover arms 314a’”, 314b’” and includes a prong tip 342a’”, 342b’” that extends toward the rear cover portion 330’”. To achieve coupling to the base 350’”, the rear cover portion 330’” includes a rear bridge 332’”, extending between cover arms 314a’”, 314b’”, and rear cover arms 334a’”, 344b’”, having inwardly extending protrusions 336a’”, 336b’”. The rear cover arms 334a’”, 344b’” also include an arc-shaped surface 338a’”, 338b’” shaped to facilitate coupling of the rear cover arms 334a’”, 344b’” with the base 350’”. Thus, the cover arms 314a’”, 314b’” and the rear prongs 329a’”, 329b’” can be configured to move as needed to allow for engagement and disengagement with other alignment features or elements included in an alignment assembly. Moreover, the cover arms 314a’”, 314b’” and the rear prongs 329a’”, 329b’” can be cantilevered to calibrate forces on an FAU alignment part.

[0052] The base 350C has a similar configuration as the base 350 illustrated in the first embodiment of the base 350C, shown in FIG. 5. Still referring to FIG. 9, the base 350C includes a rear base wall 351’”, having protrusion receiving openings 352a, 352b defined therein similar to those shown in the first embodiment of the cover. The base 350C additionally includes base sidewalls 360a’”, 360b’”, a laterally extending front base section 370’”, and a downwardly extending front base wall 380’”. The rear base wall 351’” includes an upper base wall section 354’”, and lower base wall steps 356a’”, 356b’”, having a curved step section 361’”. The upper base wall section 354’” is configured to span between base sidewalls 360a’”, 360b’”, while the lower base wall steps 356a’”, 356b’” are positionedAttorney Docket No.: HI24-073PCT slightly above the base sidewalls 360a’”, 360b’” such that there is a u-shaped opening 359’” bound by the lower base wall steps 356a’”, 356b’” and a lowermost surface 358’” of the upper base wall section 354’”. Each lower base wall step 356a’”, 356b’” is configured to have an upper step surface 357a’”, 357b’” configured such that rear covers arms 334a’”, 344b’” bias when positioned on the upper step surface 357a’”, 357b’”, as particularly shown in FIGs. 1 and 2. The lower base wall steps 356a’”, 356b’” are also configured to extend a distance past the overall length of the upper base wall section 354’” .

[0053] This embodiment of the FAU alignment system 100C, includes a receptacle assembly 400’” configured for positioning and partial containment within the base 350’”. The receptacle 400’” includes separate components: a stop element 410’” and a plate element 420’” The stop element 410”” has a plurality of engagement surfaces configured to mate with the FAU alignment element 240 and the base 350C, as particularly shown in FIG. 9. Here, the stop element 410’” is positioned between the plate element 420’” and an interior surface 371’” of the front base section 370’”. In this configuration of the receptacle assembly 400’”, the stop element 410’” has an angled stop surface 412’”, a substantially vertical stop surface 414, side stop surfaces 416a’”, 416b, a substantially horizontal stop surface 418’”, and a bottom surface 419’”. The plate element 420 includes a plurality of alignment surfaces as well, including substantially vertical first and second plate surfaces 422’”, 424’”, side plate surfaces 426a’”, 426b’”, a top plate surface 428’”, and a bottom plate surface 429’”. The top plate surface 428’” is configured for positioning against a bottommost surface of the FAU alignment element 240.

[0054] FIGs 10A, 10B and 10C schematically illustrate side views of various FAU-stop element assemblies with different FAU alignment elements and stop element configurations, which can be included in an FAU alignment system. Each FAU-stop element is coupled to an upper FAU element 210 and a lower FAU element 230. A directional element D is schematically shown to indicate a possible optical path upon full assembly. The FAU alignment element 240 A shown in FIGs. 10A and 10C includes an upwardly extending alignment portion 242B and an FAU alignment body portion 244B integrally coupled to the alignment portion 242B. The stop element configurations in FIGs. 10A and 10C are reversed. Here, the stop element 410A includes an upwardly extending stop portion 413 A and a plate portion 420A integrally coupled to the stop portion 413 A. In FIG. 10 B the stopAttorney Docket No.: HI24-073PCT element 41 OB is configured as a rectangular cuboid. The configurations of the FAU-stop element assemblies are exemplary and should not be construed as limiting.

[0055] It will be apparent to those skilled in the art that various modifications and variations can be made without departing from the spirit or scope of the disclosure. Since modifications, combinations, sub-combinations and variations of the disclosed embodiments incorporating the spirit and substance of the disclosure may occur to persons skilled in the art, the embodiments disclosed herein should be construed to include everything within the scope of the appended claims and their equivalents.

Claims

Attorney Docket No.: HI24-073PCTClaimsWhat is claimed is:

1. An FAU alignment system comprising: a base having a rear base wall, base sidewalls, and a front base section; a cover coupled to the base and movable between open and closed positions; and a receptacle supported by the base and including a stop element and a plate element, the plate element having a top plate surface and the stop element having at least two engagement surfaces oriented in different directions; wherein the rear base wall includes an upper base wall section and lower base wall steps, and the cover includes rear cover arms arranged to bias against the lower base wall steps when the cover is in the closed position so that the receptacle is pressed against the base and the top plate surface defines a repeatable mechanical reference location for an optical component received on the top plate surface.

2. The alignment system of claim 1, wherein the lower base wall steps and the upper base wall section define a u-shaped opening between the lower base wall steps and a lowermost surface of the upper base wall section.

3. The alignment system of claim 1 or claim 2, wherein the lower base wall steps extend such that a lowermost surface of each lower base wall step is configured for lateral alignment with a lowermost surface of the receptacle.

4. The alignment system of any one of claims 1 to 3, wherein the front base section includes a cantilevered lip having a chamfer extending past a downwardly extending front base wall of the base.

5. The alignment system of any one of claims 1 to 4, wherein the downwardly extending front base wall includes a front base wall extension configured to extend past lowermost surfaces of the base sidewalls and to abut against a photonic integrated circuit when the alignment system is assembled.Attorney Docket No.: HI24-073PCT6. The alignment system of any one of claims 1 to 5, wherein the cover further includes a front cover portion and a rear cover portion, and the rear cover arms extend from the rear cover portion toward the rear base wall.

7. The alignment system of any one of claims 1 to 6, wherein the cover includes cover arms having flexible portions that allow the cover arms to move and bend during engagement and disengagement of the cover with the base.

8. The alignment system of any one of claims 1 to 7, further comprising a spring element positioned between a portion of the base and a component supported near the top plate surface, the spring element being configured to exert a force that urges the component toward the stop element.

9. The alignment system of any one of claims 1 to 8, further comprising an FAU assembly / connector including an FAU cover, an upper FAU element, a lower FAU element, and an FAU alignment element, the FAU alignment element having a bottommost surface positioned on the top plate surface and v-grooves configured to receive rods or pins that cooperate with the receptacle to locate the FAU assembly / connector.

10. An alignment system comprising: a base having a rear base wall and a front base section; a cover coupled to the base and movable between open and closed positions, the cover having cover arms with flexible portions and rear cover arms configured to engage the rear base wall when the cover is in the closed position; a plate element supported on the base and defining a top plate surface configured to support an optical component; and a stop element positioned between the plate element and an interior surface of the front base section and having engagement surfaces that bear against the plate element and the base; wherein closing the cover causes the cover arms to flex so that the rear cover arms engage the rear base wall and clamp the plate element and the stop element between the cover and the base, thereby defining a repeatable alignment position for the optical component on the top plate surface.Attorney Docket No.: HI24-073PCT11. The alignment system of claim 10, wherein the stop element includes an angled stop surface and a substantially vertical stop surface configured to contact the plate element and the base in different directions.

12. The alignment system of claim 10 or claim 11, wherein the stop element further includes side stop surfaces and a substantially horizontal stop surface.

13. The alignment system of any one of claims 10 to 12, wherein the stop element is configured as a rectangular cuboid.

14. The alignment system of any one of claims 10 to 13, wherein the rear base wall includes an upper base wall section and lower base wall steps positioned such that a u-shaped opening is defined between the lower base wall steps and a lowermost surface of the upper base wall section, and the rear cover arms are configured to bias on upper step surfaces of the lower base wall steps.

15. The alignment system of any one of claims 10 to 14, wherein the lower base wall steps are positioned slightly above the base sidewalls and include a curved step section.

16. The alignment system of any one of claims 10 to 15, wherein the flexible portions of the cover arms define slots that are L-shaped or substantially horizontal and configured to allow the cover arms to move upwardly and bend during engagement or disengagement of the cover with the base.

17. The alignment system of any one of claims 10 to 16, wherein the cover includes a front cover portion having a cantilevered cover element and prongs extending from a bridge portion of the cantilevered cover element, the prongs being configured to cooperate with at least one of the plate element and the stop element to control a force applied to an alignment part coupled to an FAU assembly / connector.Attorney Docket No.: HI24-073PCT18. The alignment system of any one of claims 1 to 9 or any one of claims 10 to17, wherein an FAU alignment element having an upwardly extending alignment portion and an FAU alignment body portion integrally coupled to the alignment portion is positioned on the top plate surface as the optical component.

19. The alignment system of any one of claims 1 to 9 or any one of claims 10 to18, further comprising a microlens array and a prism configured to be supported by elements of an FAU assembly / connector and to cooperate with an FAU alignment element on the top plate surface and with at least one of the stop element and the plate element to define an optical path relative to the base.

20. The alignment system of any one of claims 1 to 9 or any one of claims 10 to19, wherein at least one of the base, the cover, the receptacle, the receptacle assembly, the stop element, the plate element, and the spring element is configured to be coupled to the FAU assembly / connector.

Images