Stacked ferrules for on-board optical interconnects

Abstract

A stack of optical ferrules, each optical ferrule including a top surface having a mounting area for an optical waveguide, a light redirecting member, and a bottom surface having an exit window. When an optical waveguide is mounted in the mounting area, a central light ray emitted from the optical waveguide is redirected by the light redirecting member and exits the optical ferrule through the exit window. In each pair of adjacently stacked top and bottom optical ferrules, the exit central light ray of the top optical ferrule enters the bottom optical ferrule through the top surface of the bottom optical ferrule and exits the bottom optical ferrule through the exit window of the bottom optical ferrule. Each of the exit central light rays of each optical ferrule exits the exit window of the bottom optical ferrule at a different location.

Description

[Technical Field]

[0001] [Summary of the Invention] In some aspects of the present disclosure, a plurality of individual, independent optical ferrules are provided, assembled along a thickness direction of the optical ferrules to form a stack of optical ferrules. Each optical ferrule includes an upper surface and a lower surface opposite the upper surface. The upper surface includes a plurality of mounting areas for receiving and permanently attaching a plurality of corresponding optical waveguides, and a light redirecting member. The lower surface of each optical ferrule includes an exit window. The upper and lower surfaces define a thickness direction of the optical ferrule therebetween, and when an optical waveguide is received and permanently attached in the mounting area, a central light ray emitted from the optical waveguide is redirected by the light redirecting member and exits the optical ferrule through the exit window as an exit central light ray. For each pair of adjacently stacked upper and lower optical ferrules in the plurality of stacked optical ferrules, the exit central light ray of the upper optical ferrule enters the lower optical ferrule through the upper surface of the lower optical ferrule and exits the lower optical ferrule through the exit window of the lower optical ferrule. Each of the exit central rays incident on each of the plurality of optical ferrules exits the exit window of the lowest optical ferrule at a different position on the exit window of the lowest optical ferrule.

[0002] In some aspects of the present disclosure, a plurality of optical ferrules are provided. Each of the plurality of optical ferrules includes a light redirecting member and an exit window. The light redirecting member is configured to receive one or more central light rays emitted from one or more corresponding optical waveguides attached to the optical ferrule along a first direction and redirect the received one or more central light rays in a different second direction to form one or more redirected central light rays. The redirected central light rays exit the optical ferrule through the exit window of the optical ferrule as one or more exit central light rays. Each of the one or more exit central light rays of each optical ferrule passes through a different exit position of the exit window of the same optical ferrule among the plurality of optical ferrules.

[0003] In some aspects of the present disclosure, an optical stack is provided. The optical stack includes a plurality of optical ferrules assembled along a thickness direction of the optical ferrules. Each optical ferrule is configured such that a plurality of central light rays emitted from a corresponding plurality of optical waveguides optically coupled to the optical ferrule enter the optical ferrule along a first direction, are bent by the optical ferrule, and exit the optical stack through the same exit surface of the optical stack along a different second direction. The central light rays enter each optical ferrule along the first direction and exit the optical stack through the exit surface of the optical stack after passing through all other optical ferrules disposed between the optical ferrule and the exit surface. [Brief explanation of the drawings]

[0004] [Figure 1] FIG. 1 is a perspective view of an optical stack including a plurality of individual optical ferrules according to one embodiment of the present disclosure. [Figure 2A] FIG. 2A shows an exploded view of an optical stack according to one embodiment of the present disclosure. [Figure 2B] FIG. 2B shows an exploded view of an optical stack according to one embodiment of the present disclosure. [Figure 2C] FIG. 2C shows an exploded view of an optical stack according to one embodiment of the present disclosure. [Figure 3A] FIG. 3A illustrates how individual optical ferrules in an optical stack according to one embodiment of the present disclosure are offset relative to one another. [Figure 3B] FIG. 3B illustrates how the individual optical ferrules in an optical stack according to one embodiment of the present disclosure are offset relative to one another. [Figure 4] FIG. 4 illustrates how individual optical ferrules in an optical stack according to one embodiment of the present disclosure are offset widthwise relative to one another. [Figure 5A] FIG. 5A illustrates how individual optical ferrules in an optical stack according to one embodiment of the present disclosure are offset relative to one another in multiple dimensions. [Figure 5B]FIG. 5B illustrates how individual optical ferrules in an optical stack according to one embodiment of the present disclosure are offset relative to one another in multiple dimensions. [Figure 6] FIG. 6 is an additional perspective view of an optical stack according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0005] In the following description, reference is made to the accompanying drawings, which form a part of this specification and in which are shown, by way of illustration, various embodiments. The drawings are not necessarily drawn to scale. It is to be understood that other embodiments are contemplated and may be made without departing from the scope or spirit of the present specification. Accordingly, the following detailed description is not to be taken in a limiting sense.

[0006] The integrated photonics industry, also known as silicon photonics, is rapidly innovating following a paradigm pioneered by the microelectronics industry. Tiny optical circuits will be tightly integrated with traditional silicon microchip circuitry to improve data transfer within the microchip and eventually transfer data outside the microchip. As data communication bandwidth continues to increase over time, the number of input / output ports is expected to increase accordingly. Input / output ports are most often located on the periphery, as the key features that provide the most valuable functionality are located inside the chip.

[0007] The primary constraint on expanding the number of ports indefinitely is the diameter of optical fiber, the standard conduit for transporting data off the chip. Fiber diameters come in standard sizes, such as 125 microns or 80 microns in cladding diameter. Increasing the number of channels on a chip by simply increasing the number of fibers in a linear array will eventually result in a lack of space, since the chip size will not increase. Rather, the industry expects chip size to decrease as technology advances. The industry is seeking ways to increase the number of channels without exceeding the chip's size constraints. To increase the number of input / output ports on a microchip that can be feasibly coupled to optical fiber, one or more rows of ports along the edge of the chip are proposed.

[0008] According to some aspects of the present disclosure, a plurality of individual, independent optical ferrules are assembled along a thickness direction of the optical ferrules (e.g., the z-axis of the optical stack) to form a stack of optical ferrules. In some embodiments, the optical ferrules may be removably assembled (i.e., the optical ferrules can be separated from one another as needed). In some embodiments, the plurality of optical ferrules may include at least three individual, independent optical ferrules. In some embodiments, each optical ferrule may include a top surface and a bottom surface opposite the top surface, and a thickness direction may be defined between the top surface and the bottom surface. In some embodiments, the optical ferrules in the stack of optical ferrules may be glued together, held in the stack by mechanical features (e.g., one or more alignment or engagement features), clamped together, or assembled in any suitable manner.

[0009] In some embodiments, the top surface may include a plurality of mounting areas for receiving and permanently mounting a plurality of corresponding optical waveguides (e.g., optical fibers) and a light redirecting member. In some embodiments, the mounting area of ​​each optical ferrule may include a plurality of grooves extending along the length of the optical ferrule. In some embodiments, each groove may be configured to receive and permanently mount one of the plurality of corresponding optical waveguides.

[0010] In some embodiments, the lower surface may include an exit window. In some embodiments, when the light guide is received in the mounting region and permanently attached, a central light ray is emitted from the light guide, redirected by the light redirecting member, and exits the optical ferrule through the exit window as an exit central light ray. In some embodiments, the central light ray emitted from the light guide may be redirected by the light redirecting member at an angle of at least 40 degrees, or at least 50 degrees, or at least 60 degrees, or at least 70 degrees, or at least 80 degrees. In some embodiments, the central light ray emitted from the light guide is redirected by the light redirecting member at a redirection angle, and the redirection angles of the optical ferrules differ by less than about 10 degrees, or less than about 8 degrees, or less than about 6 degrees, or less than about 4 degrees, or less than about 3 degrees, or less than about 2 degrees, or less than about 1 degree (i.e., the redirection angles of the different optical ferrules cause the central light rays emitted from the multiple optical ferrules to be substantially parallel).

[0011] In some embodiments, for each pair of adjacently stacked upper and lower optical ferrules of the plurality of stacked optical ferrules, the exit central ray of the upper optical ferrule enters the lower optical ferrule through a top surface of the lower optical ferrule and exits the lower optical ferrule through an exit window of the lower optical ferrule. In some embodiments, each of the exit central ray incident on a respective optical ferrule of the plurality of optical ferrules exits the exit window of the bottom optical ferrule at a different position of the exit window of the bottom optical ferrule.

[0012] In some embodiments, the central light rays emitted from the light guides are incident on the light redirecting members of the optical ferrules at substantially linear incident lines, and the incident lines of each ferrule may be offset from one another along a common length (e.g., the x-axis) of the ferrules. In some embodiments, the central light rays emitted from the light guides are incident on the light redirecting members of the ferrules at corresponding spaced-apart incident positions, and in a plan view across the thickness of the ferrules, the incident positions on the light redirecting members of the ferrules may form a two-dimensional array, and no incident position in the array may overlap with any other incident position in the array.

[0013] In some embodiments, each optical ferrule may further include a pair of opposing side walls spaced apart along the width of the optical ferrule (e.g., the y-axis), extending along the length of the optical ferrule (e.g., the x-axis), and joining the top and bottom surfaces of the optical ferrule.

[0014] In some embodiments, each optical ferrule further includes an input member, and when the optical waveguide is received in the mounting region and permanently attached, a central light ray emitted from the optical waveguide may enter the optical ferrule through the input member of the optical ferrule. In such embodiments, the incoming central light ray may enter the light redirecting member along a first direction, and the light redirecting member may redirect the incoming central light ray in a different second direction. In some embodiments, the redirected central light ray may exit the optical ferrule through an exit window of the optical ferrule as an exit central light ray. In some such embodiments, for each optical ferrule, the incoming central light ray and the redirected central light ray may form an angle between approximately 30 degrees and 150 degrees.

[0015] In some embodiments, the exit window of at least one optical ferrule may have an anti-reflective coating thereon that reduces the reflection of incident light having wavelengths greater than about 500 nm, or greater than about 600 nm, or greater than about 700 nm, or greater than about 800 nm, or greater than about 900 nm, or greater than about 1000 nm by at least 1%, or at least 2%, or at least 3%.

[0016] According to some aspects of the present disclosure, each optical ferrule of the plurality of optical ferrules includes a light redirecting member configured to receive one or more central light rays emitted from one or more corresponding optical waveguides attached to the optical ferrule along a first direction and redirect the received one or more central light rays in a different second direction into one or more redirected central light rays. In some embodiments, the redirected central light rays exit the optical ferrule through an exit window of the optical ferrule as one or more exit central light rays. In some embodiments, each of the one or more exit central light rays of a respective optical ferrule passes through a different exit position of the exit window of the same optical ferrule in the plurality of optical ferrules.

[0017] In some embodiments, a plurality of optical ferrules are permanently or removably assembled along a thickness direction of the optical ferrules (e.g., along the z-axis) to form a stack of optical ferrules. In some such embodiments, the optical ferrules of the plurality of optical ferrules may be substantially identical, and the optical ferrules may be offset from one another at least along a common length direction (e.g., the x-axis).

[0018] In some embodiments, an optical communication system may include a plurality of optical ferrules, such as those described herein, disposed on a substrate. In some embodiments, the substrate may comprise a plurality of optical elements (e.g., optical gratings, silicon photonics chips, sensors, etc.). In such embodiments, each of one or more exit central beams of each optical ferrule passing through a different exit position of an exit window of the same optical ferrule may be optically coupled to a different optical element of the plurality of optical elements. In some such embodiments, at least one optical ferrule of the plurality of optical ferrules may be substantially identical to at least one other optical ferrule of the plurality of optical ferrules.

[0019] According to some aspects of the present disclosure, an optical stack includes a plurality of optical ferrules assembled along a thickness direction (e.g., z-axis) of the optical ferrules. In some embodiments, each optical ferrule may be configured such that a plurality of central light rays emitted from a corresponding plurality of optical waveguides (e.g., optical fibers) optically coupled to the optical ferrule enter the optical ferrule along a first direction (e.g., along the x-axis of the optical ferrule) and are bent by the optical ferrule to exit the optical stack through the same exit surface of the optical stack along a different second direction. In some embodiments, the central light rays entering each optical ferrule along the first direction may exit the optical stack through the exit surface of the optical stack after passing through all other optical ferrules disposed between the optical ferrule and the exit surface. In some embodiments, the optical ferrules of the plurality of optical ferrules may be substantially identical. In some embodiments, at least one optical ferrule may be different from at least one other optical ferrule.

[0020] In some embodiments, the optical ferrules in each pair of adjacent optical ferrules of the plurality of optical ferrules can be offset from one another along both the length (e.g., x-axis) and width (e.g., opposing y-axes) of the optical ferrules.

[0021] Turning to the figures, Figure 1 is a perspective view of an optical stack 100 including multiple individual optical ferrules, and Figures 2A-2C show various exploded views of the optical stack 100 of Figure 1. Figure 1 and Figures 2A-2C should be referenced together for the following discussion.

[0022] In some embodiments, the optical stack 100 may include multiple individual, separate optical ferrules 10, 20. In some embodiments, the optical ferrules 10, 20 may be removably or permanently assembled along the thickness direction of the optical ferrules 10, 20 (e.g., the z-axis shown in FIG. 1 ) to form the optical stack 100.

[0023] In some embodiments, each optical ferrule may include an upper surface 11, 21 and a lower surface 14, 24 (see also FIG. 2C) opposite the upper surface 11, 21. In some embodiments, the upper surface 11, 21 and the lower surface 14, 24 define a thickness direction of the optical ferrule 10, 20 therebetween (corresponding to the z-direction defined in FIG. 1). In some embodiments, the upper surface 11, 21 may include a plurality of attachment regions 12, 22 (see also FIG. 2A) for receiving and permanently attaching a plurality of corresponding optical waveguides 30, 40. In some embodiments, the upper surface 11, 21 may also include a light redirecting member 13, 23.

[0024] In some embodiments, each optical ferrule 10, 20 may further include a pair of opposing side walls 17a, 17b (see FIGS. 1 and 2A) spaced apart along the width of the optical ferrule 10, 20 (e.g., the y-axis shown in FIGS. 1 and 2A), extending along the length of the optical ferrule 10, 20 (e.g., the x-axis), and joining the upper surfaces 11, 12 and the lower surfaces 14, 24 of the optical ferrule 10, 20.

[0025] In some embodiments, the lower surface 14, 24 of the optical ferrule 10, 20 may include an exit window 15, 25 (see FIG. 2C ). In some embodiments, as shown in FIG. 2B , when the optical waveguide 30, 40 is received and permanently attached in the attachment region 12, 22, a central light ray 34 emitted from the optical waveguide 30, 40 is redirected by the light redirecting member 13, 23 into a redirected central light ray 33 that exits the optical ferrule 10, 20 through the exit window 15, 25.

[0026] In some embodiments, the exit window 15, 25 of at least one optical ferrule 10, 20 may have an anti-reflective coating 80 thereon that reduces the reflection of incident light having wavelengths greater than about 500 nm, or greater than about 600 nm, or greater than about 700 nm, or greater than about 800 nm, or greater than about 900 nm, or greater than about 1000 nm by at least 1%, or at least 2%, or at least 3%.

[0027] In some embodiments, each optical ferrule 10, 20 further includes an input member 18 (e.g., a surface adjacent the end of the optical fiber 30, 40, see FIG. 2A ), and when the optical waveguide 30, 40 is received in and permanently attached to the attachment region 12, 22, a central light ray 34 emitted from the optical waveguide 30, 40 may enter the optical ferrule 10, 20 through the input member 18.

[0028] In some embodiments, the incident central light ray 34 and the redirected central light ray 33 may form an angle α1 between about 30 degrees and 150 degrees. In some embodiments, the redirected central light ray 33 emitted from the light guide 10, 20 is redirected by the light redirecting member at an angle α2 of at least 40 degrees, or at least 50 degrees, or at least 60 degrees, or at least 70 degrees, or at least 80 degrees.

[0029] Note that in FIG. 2B , only the central ray 34 of the top optical ferrule 10 is shown for clarity. However, the optical ferrule 20 may also have a similar central ray that is emitted from the light guide 40, redirected by the light redirecting member 23, and exits through the exit window 25. Furthermore, when the optical stack 100 is fully assembled, the redirected central ray 33 that exits through the exit window 15 of the optical ferrule 10 passes through the optical ferrule 20 and exits through an exit location on the bottom surface 24 of the optical ferrule 20. This concept is shown in at least more detail in FIG. 5 . Also, note that while the examples shown in FIGS. 1 and 2A-2C show two optical ferrules (optical ferrule 10 and optical ferrule 20), embodiments according to the present specification can include any suitable number of optical ferrules, such as three, four, five, six, etc. These examples are not intended to be limiting.

[0030] 3A and 3B illustrate how individual optical ferrules within an optical stack, such as optical stack 100 of the preceding figures, are offset relative to one another. Figure 3A is a front view of optical stack 100, and Figure 3B is a top view of optical stack 100. (Note: the bodies of optical ferrules 10 and 20 have been omitted from Figure 3B for clarity.)

[0031] In some embodiments, multiple individual, independent optical ferrules (e.g., 10, 20 in FIG. 3A ) may form an optical stack 100. In some embodiments, when an optical waveguide (e.g., optical waveguides 30, 40 in FIG. 1 ) is received in and permanently attached to the mounting region (e.g., mounting regions 12, 22 in FIG. 1 ) of each optical ferrule 10, 20, a central light ray emitted from the optical waveguide 30, 40 enters the light redirecting member 13, 23 of the corresponding optical ferrule 10, 20 on a substantially straight incident line of sight (e.g., line 16 for optical ferrule 10 and line 26 for optical ferrule 20, along the y-axis in FIG. 3A ), and the incident lines 16, 26 of the optical ferrules 10, 20 are offset from one another along the common length of the optical ferrules 10, 20 (e.g., along the x-axis shown in FIG. 1 ). That is, the incident line 16 is offset in the x-direction (i.e., into or out of the page) relative to the incident line 26. This offset is best illustrated in FIG. 3B, which shows a top view of incident rays 16 and 26, illustrating how incident rays 16 and 26 are offset in the x-direction.

[0032] In some embodiments, central light rays emitted from optical waveguides 30, 40 may be incident on light redirecting members 13, 23 of optical ferrules 10, 20 at corresponding spaced-apart incident positions (e.g., incident positions 16a-16h for incident ray 16 and incident positions 26a-26h for incident ray 26). In some embodiments, in a planar view across the thickness of optical ferrules 10, 20 (e.g., from the perspective of FIG. 3B), incident positions 16a-16h and 26a-26h form a two-dimensional array 60, and no incident position in array 60 overlaps with any other incident position in array 60. That is, in the embodiment shown in FIGS. 3A and 3B, incident lines 16 and 26 (and their corresponding incident positions 16a-16h, 26a-26h) are offset in both the x- and y-directions shown in FIGS. 3A and 3B. Due to the stacked nature of optical ferrules 10 and 20, incident lines 16 and 26 are also offset in the z-direction, ie, thickness direction.

[0033] 4 is a front view of an embodiment of optical stack 100a similar to the embodiment of optical stack 100 shown in FIG. 3A, showing a third optical ferrule 70 in addition to optical ferrules 10 and 20. Like optical ferrules 10 and 20, optical ferrule 70 can, in some embodiments, be characterized by an incidence line 76 defined by incidence locations 76a-76h. Each of incidence locations 76a-76h represents an incidence point that defines a substantially straight incidence line 76 intersecting a central ray of light entering light redirecting member 73 of optical ferrule 70.

[0034] In some embodiments, the optical ferrules 10, 20, 70 of each pair of adjacent optical ferrules may be offset from one another along the length (e.g., the x-axis shown in FIG. 4 ) and width (e.g., the y-axis in FIG. 4 ) of the optical ferrules 10, 20, 70. For example, the optical ferrule 10 is offset from the optical ferrule 20, such that the entrance positions 16a-16h of the optical ferrule 10 are offset from the entrance positions 26a-26h of the optical ferrule 20 in both the x- and y-directions in FIG. 4 . Similarly, the optical ferrule 20 is offset from the optical ferrule 70, such that the entrance positions 26a-26h of the optical ferrule 20 are offset from the entrance positions 76a-76h of the optical ferrule 70 in both the x- and y-directions in FIG. 4 .

[0035] In some embodiments, at least one ferrule of the plurality of ferrules may be substantially identical to at least one other ferrule of the plurality of ferrules. In some embodiments, at least one ferrule of the plurality of ferrules may be structurally different from at least one other ferrule of the plurality of ferrules. In some embodiments, the ferrules of the plurality of ferrules may be offset in a width direction (e.g., the y-direction in FIG. 4 ) such that each ferrule in the optical stack 100 alternates between a first offset value and a second offset value. For example, the width offset of ferrule 10 may be substantially the same as the width offset of ferrule 70 (i.e., both are offset by the same first offset value), while the width offset of intervening ferrule 20 may be a different second value. This is illustrated in FIG. 4 by the vertical dashed line passing through entry point 16h of ferrule 10 and entry point 76h of ferrule 70, and then passing back between entry points 26g and 26h of ferrule 20.

[0036]

[0023] Figures 5A and 5B illustrate how individual optical ferrules within an optical stack are offset from one another in multiple dimensions. Figure 5A is a side view of optical stack 100A of Figure 4, and Figure 5B illustrates a top view of incident lines 16, 26, and 76 of Figure 4. As shown in Figure 5B, in optical stack 100A, optical ferrules 10, 20, and 70 are offset from one another along the length of the optical ferrules (e.g., the x-direction in Figure 5A).

[0037] In some embodiments, when an optical waveguide 30, 40, 90 is received and permanently attached in the mounting region of an optical ferrule 10, 20, 70, a central light ray 31, 41, 91 can be emitted from the corresponding optical waveguide, redirected by the light redirecting member 13, 23, 73, and exit the corresponding optical ferrule through the corresponding exit window in a second (redirected) direction 52 as an exit central light ray 32, 42, 92.

[0038] In some embodiments, for each pair of adjacent stacked upper and lower optical ferrules 10, 20 and 20, 70 in the plurality of stacked optical ferrules, the exit central light ray 32, 42, 92 of the upper optical ferrule enters the lower optical ferrule through the top surface of the lower optical ferrule and exits the lower optical ferrule through the exit window of the lower optical ferrule. That is, the exit central light ray of each optical ferrule may enter the optical ferrule immediately below it (if present). For example, the exit central light ray 32 exits optical ferrule 10, enters and passes through optical ferrule 20, then enters and passes through optical ferrule 70, exiting the optical stack 100A from the bottom surface 74 of the bottom optical ferrule 70. In some embodiments, the exit central light ray 32, 42, 92 of each optical ferrule 10, 20, 70 in the plurality of optical ferrules exits at different positions 25a, 25b, 25c of the exit window 75 of the bottom optical ferrule 70.

[0039] In some embodiments, the optical communication system 200 may include an optical stack 100A disposed on a substrate 50. In some embodiments, the substrate 50 may include multiple optical elements 51 a, 51 b, 51 c. In some embodiments, one or more exit central light rays 32, 42, 92 of each optical ferrule 10, 20, 70 passing through different exit positions 25 a, 25 b, 25 c of the exit window 75 of the same optical ferrule 70 may be optically coupled to different optical elements 51 a, 51 b, 51 c of the multiple optical elements.

[0040] FIG. 5B illustrates, in a top view, the alignment of incident lines 16, 26, and 76 (and their respective incident positions 16a-16h, 26a-26h, and 76a-76h) in one embodiment of optical stack 100A. In some embodiments, incident lines 16, 26, and 76 can be offset from one another in both the x-direction (i.e., along the length of the ferrule) and the y-direction (i.e., across the width). Assuming that each incident position (denoted by "x" in FIG. 5B) represents an incident point on a corresponding light redirecting member of the optical ferrule and that all redirected (exit) central rays (e.g., exit central rays 32, 42, and 92 in FIG. 5A) are substantially parallel, a corresponding pattern of optical elements 51 can be disposed on substrate 51, with each optical element 51 receiving an exit ray corresponding to the incident point shown in FIG. 5B. A two-dimensional array of optical elements 51 on substrate 50 corresponds to the two-dimensional array of incident points shown in FIG. 5B, and can provide an increased number (a denser pattern) of input / output ports on the substrate.

[0041] Finally, Figure 6 is an additional view of an embodiment of the optical stack that provides another viewing angle and additional detail and clarity of the optical stack 100. Many of the elements shown in Figure 6 have already been discussed in other figures and descriptions and should be assumed to have the same function as previously described unless otherwise specified.

[0042] In some embodiments, the optical stack 100 may include multiple optical ferrules, such as optical ferrule 10 and optical ferrule 20 (or in other embodiments, any suitable number of optical ferrules). Each optical ferrule 10, 20 may receive and attach multiple optical waveguides 30, 40 (e.g., multiple optical fibers). In some embodiments, each optical ferrule 10, 20 further includes an input member (e.g., an input face) 18, such that when the optical waveguides 30, 40 are received and permanently attached in the attachment region, a central light ray 31, 41 emitted from the optical waveguides 30, 40 enters the optical ferrule 10, 20 through the input member 18, and the incident central light ray 34 may enter the light redirecting member 13, 23 along an incident line 16, 26 in a first direction 31 a and be redirected by the light redirecting member 13, 23 to a different second direction 31 b. In some embodiments, the redirected central light rays 33, 43 exit the optical ferrules 10, 20 as exit central light rays 32, 42 through the exit window 15, 25 of the corresponding optical ferrule 10, 20. In some embodiments, one or more exit central light rays 32, 42 of each optical ferrule pass through different exit locations 25a, 25b of the exit window 25 of the same optical ferrule 20. Note that the exit central light ray 32 leaves the optical ferrule 10 through the exit window 15 and enters the optical ferrule 20 through the top surface 21 of the optical ferrule 20 before exiting the optical stack 100 through the exit window 25 of the optical ferrule 20.

[0043] The term "about" is used herein and in the context described, and will be understood by those skilled in the art. When the use of "about" as applied to quantities expressing feature sizes, amounts, and physical properties is not clear to those skilled in the art in the context described herein, "about" is understood to mean within 10% of the specified value. A quantity given as "about" a specified value may be the exact specified value. For example, when used herein and in the context described, and not clear to those skilled in the art, an amount having a value of about 1 means that the amount has a value between 0.9 and 1.1, and may be 1.

[0044] The term "substantially" is used herein and will be understood by those skilled in the art in the context in which it is described. When the use of "substantially equal" is used herein and is not clear to those skilled in the art in the context in which it is described, "substantially equal" means "approximately equal," similar to "about" above. When the use of "substantially parallel" is used herein and is not clear to those skilled in the art in the context in which it is described, "substantially parallel" means within 30 degrees of parallel. Directions or surfaces described as being substantially parallel to each other may, in some embodiments, be within 20 degrees or within 10 degrees of parallel, or may be parallel or nominally parallel. When the use of "substantially aligned" is used herein and is not clear to those skilled in the art in the context in which it is described, "substantially aligned" means aligned within 20% of the width of the objects being aligned. In some embodiments, objects described as being substantially aligned may be aligned within 10% or within 5% of the width of the objects being aligned.

[0045] All references, patents, and patent applications set forth above are hereby incorporated by reference in their entirety in a consistent manner. In the event of any conflict or inconsistency between the portions of the incorporated references and this application, the information in the above description shall control.

[0046] Descriptions of elements in a figure should be understood to apply equally to corresponding elements in other figures, unless otherwise indicated. While specific embodiments have been shown and described herein, it will be understood by those skilled in the art that various alternative and / or equivalent embodiments may be substituted for the specific embodiments shown and described without departing from the scope of the present disclosure. This application is intended to cover any adaptations or variations of the specific embodiments discussed herein. Accordingly, the present disclosure is intended to be limited only by the claims and equivalents thereof.

Claims

1. A plurality of individual, independent optical ferrules are assembled along a thickness direction of the optical ferrules to form a stack of the optical ferrules, each of the optical ferrules having: a top surface including a plurality of mounting areas for receiving and permanently mounting a plurality of corresponding light guides and a light redirecting member; a lower surface opposite the upper surface and including an exit window; a thickness direction of the optical ferrule is defined between the upper surface and the lower surface, and when the optical waveguide is received in the mounting region and permanently attached, a central light ray emitted from the optical waveguide is redirected by the light redirecting member to exit the optical ferrule through the exit window as an exit central light ray; In each pair of adjacently stacked upper and lower optical ferrules of the plurality of stacked optical ferrules, an exit central light ray of the upper optical ferrule passes through an upper surface of the lower optical ferrule and enters the lower optical ferrule through an exit window of the lower optical ferrule, and each exit central light ray that strikes each optical ferrule of the plurality of optical ferrules exits the exit window of the lowermost optical ferrule at a different position from the exit window of the lowermost optical ferrule. Multiple individual, independent optical ferrules.

2. 10. The plurality of individual, independent optical ferrules of claim 1, wherein said optical ferrules are removably assembled.

3. 2. The plurality of individual, independent optical ferrules of claim 1, wherein when the optical waveguides are received in and permanently attached to respective mounting regions of the optical ferrules, central light rays emitted from the optical waveguides are incident on the light redirecting members of the optical ferrules on substantially straight lines of incidence, the lines of incidence of the optical ferrules being offset from one another along a common length of the optical ferrules.

4. 2. The plurality of individual, independent optical ferrules of claim 1, wherein when the optical waveguides are received in and permanently attached to respective mounting regions of the optical ferrules, central light rays emitted from the optical waveguides are incident on the light redirecting members of the optical ferrules at corresponding spaced-apart incident locations, and when viewed in a plan view through a thickness of the optical ferrules, the incident locations on the light redirecting members of the optical ferrules form a two-dimensional array, and no incident location in the array overlaps with any other incident location in the array.

5. The plurality of individual, independent optical ferrules of claim 1 comprising at least three individual, independent optical ferrules.

6. 10. The plurality of individual, independent optical ferrules of claim 1, wherein each mounting region of the optical ferrules is configured to receive and permanently mount a corresponding one of the optical waveguides, the optical waveguides comprising optical fibers.

7. 10. The plurality of individual, independent optical ferrules of claim 1, wherein each of the optical ferrules further includes a pair of opposing side walls spaced apart along a width of the ferrule, extending along a length of the ferrule, and joining upper and lower surfaces of the ferrule.

8. 10. The plurality of individual, independent optical ferrules of claim 1, wherein the mounting region of each of the optical ferrules includes a plurality of grooves extending along a length of the optical ferrule, each groove configured to receive and permanently mount a corresponding one of the optical waveguides.

9. 2. The plurality of individual, independent optical ferrules of claim 1, wherein each of the optical ferrules further comprises an input member, and when the optical waveguides are received and permanently attached in the attachment region, a central light ray emitted from the optical waveguides enters the optical ferrule through the input member of the optical ferrule, the entering central light ray enters the optical ferrule along a first direction, the light redirecting member redirects the incident central light ray in a different second direction, and the redirected central light ray exits the optical ferrule through an exit window of the optical ferrule as an exit central light ray.

10. 10. The plurality of individual, independent optical ferrules of claim 9, wherein for each of said optical ferrules, the incident central ray and the redirected central ray form an angle between about 30 degrees and 150 degrees.

11. 10. The plurality of individual, independent optical ferrules of claim 1, wherein a central light ray emitted from said optical waveguide is redirected by said light redirecting member through an angle of at least 40 degrees.

12. 10. The plurality of individual, independent optical ferrules of claim 1, wherein central light rays emitted from the optical waveguides are redirected by the light redirecting member at a redirection angle, and the difference in redirection angles of the optical ferrules is less than about 10 degrees.

13. 10. The plurality of individual, independent optical ferrules of claim 1, wherein an exit window of at least one of the optical ferrules comprises an anti-reflective coating that reduces reflection of incident light having a wavelength greater than about 500 nm by at least 1%.

14. 1. A plurality of optical ferrules, each of the optical ferrules comprising a light redirecting member configured to receive one or more central light rays emitted from one or more corresponding optical waveguides attached to the optical ferrule along a first direction and redirect the received one or more central light rays in a different second direction into one or more redirected central light rays, the redirected central light rays exiting the optical ferrule through an exit window of the optical ferrule as one or more exit central light rays, each of the one or more exit central light rays of a respective one of the optical ferrules passing through a different exit position of the exit window of a same optical ferrule among the plurality of optical ferrules.

15. The plurality of optical ferrules according to claim 14 , wherein the plurality of optical ferrules are detachably assembled along a thickness direction of the optical ferrules to form a stack of the optical ferrules.

16. 16. The plurality of optical ferrules of claim 15, wherein the optical ferrules of the plurality of optical ferrules are substantially identical, and the optical ferrules are offset from one another along at least a common length of the optical ferrules.

17. 15. An optical communication system comprising a plurality of optical ferrules according to claim 14 arranged on a substrate including a plurality of optical elements, wherein each of one or more exit central light rays of each of the optical ferrules passing through different exit positions of an exit window of the same optical ferrule is optically coupled to a different optical element of the plurality of optical elements.

18. 20. The optical communication system of claim 17, wherein at least one optical ferrule of said plurality of optical ferrules is substantially identical to at least one other optical ferrule of said plurality of optical ferrules.

19. 1. An optical stack including a plurality of optical ferrules assembled along a thickness direction of the optical ferrules, each of the optical ferrules configured such that a plurality of central light rays emitted from a corresponding plurality of optical waveguides optically coupled to the optical ferrule enter the optical ferrule along a first direction, are bent by the optical ferrule, and exit the optical stack through a same exit surface of the optical stack along a different second direction, and the central light rays entering each of the optical ferrules along the first direction exit the optical stack through the exit surface of the optical stack after passing through all other optical ferrules disposed between the exit surface and the optical ferrule.

20. 20. The optical stack of claim 19, wherein the optical ferrules of the plurality of optical ferrules are substantially identical.

21. 20. The optical stack of claim 19, wherein the optical ferrules of each pair of adjacent optical ferrules of the plurality of optical ferrules are offset from one another along both a length and a width of the optical ferrules.

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