Stacked ferrule for on-board optical interconnectors

Abstract

A stack of optical ferrules, each of the optical ferrules including a top surface having an attachment region for an optical waveguide and a light redirecting member, and a bottom surface having an exit window. When an optical waveguide is attached to the attachment area, central light emitted by the optical waveguide is redirected by the light redirecting member and exits from the optical ferrule through the exit window. For each pair of adjacently stacked upper optical ferrule and lower optical ferrule, the emergent central light of the upper optical ferrule enters the lower optical ferrule through the top surface of the lower optical ferrule and exits from the lower optical ferrule through the emergent window of the lower optical ferrule. Each of the emergent central light rays of each of the optical insertion cores is emitted out of the emergent window of the lowermost optical insertion core at different positions.

Description

Summary of the invention

[0001] In some aspects of the present specification, a plurality of separate discrete optical ferrules are provided, which are assembled along the thickness direction of the optical ferrule to form a stack of optical ferrules. Each of the optical ferrules includes a top surface and a bottom surface opposite to the top surface. The top surface includes a light redirecting member and a plurality of attachment areas for receiving and permanently attaching to a plurality of corresponding optical waveguides. The bottom surface of each optical ferrule in the optical ferrule includes an exit window. The top surface and the bottom surface define the thickness direction of the optical ferrule between them, so that when the optical waveguide is received and permanently attached to the attachment area, the central light emitted by the optical waveguide is redirected by the light redirecting member and exits from the optical ferrule as an exit central light through the exit window. For each pair of adjacently stacked upper optical ferrules and lower optical ferrules in the plurality of stacked optical ferrules, the exit central light of the upper optical ferrule enters the lower optical ferrule through the top surface of the lower optical ferrule, and exits from the lower optical ferrule through the exit window of the lower optical ferrule. Each outgoing central light ray of each optical ferrule in the plurality of optical ferrules exits the outgoing window of the lowermost optical ferrule at a different position of the outgoing window of the lowermost optical ferrule.

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

[0003] In some aspects of the present specification, an optical stack is provided, the optical stack comprising a plurality of optical ferrules assembled along a thickness direction of an optical ferrule. Each of the optical ferrules is configured such that a plurality of central light rays emitted by a corresponding plurality of optical waveguides optically coupled to the optical ferrule enter the optical ferrule along a first direction, 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. The central light rays enter each of the optical ferrules along the first direction, and after passing through each of the other optical ferrules disposed between the optical ferrule and the exit surface, exit the optical stack through the exit surface of the optical stack. BRIEF DESCRIPTION OF THE DRAWINGS

[0004] Figure 1is a perspective view of an optical stack including a plurality of individual optical ferrules according to one embodiment of the present specification;

[0005] FIG. 2A to FIG. 2C Various exploded views of an optical stack according to one embodiment of the present specification are provided;

[0006] FIG. 3A to FIG. 3B shows how individual optical ferrules in an optical stack are offset relative to each other according to one embodiment of the present specification; and

[0007] Figure 4 shows how individual optical ferrules in an optical stack may be offset relative to each other in the width dimension according to one embodiment of the present specification;

[0008] Figure 5A and Figure 5B shows how individual optical ferrules in an optical stack may be offset relative to each other in multiple dimensions according to one embodiment of the present specification; and

[0009] Figure 6 are additional perspective views of an optical stack according to an embodiment of the present description. DETAILED DESCRIPTION

[0010] In the following description, reference is made to the accompanying drawings, which form a part of the present disclosure and in which various embodiments are shown by way of example. The drawings are not necessarily drawn to scale. It should be understood that other embodiments may be envisioned and carried out without departing from the scope or essence of the present specification. Therefore, the following specific embodiments should not be considered to have a limiting meaning.

[0011] The integrated photonics industry (also known as the silicon photonics industry) is experiencing rapid innovation that follows the paradigm pioneered by the microelectronics industry. Microscopic optical circuits will be tightly integrated with conventional silicon microchip circuits to improve data transmission within the microchip and, eventually, outside the microchip. As data communication bandwidth continues to increase over time, the number of input / output ports is expected to increase accordingly. Since the primary features that provide the most valuable functionality are located inside the chip, input / output ports are most often found on the chip periphery.

[0012] One major limiting factor to increasing the number of ports indefinitely is the diameter of the optical fiber, which is the standard channel for transmitting data outside the chip. The optical fiber diameter is a standard size, with a cladding diameter such as 125 microns or 80 microns. Increasing the number of channels on a chip by simply increasing the number of optical fibers in a linear array will eventually run out of space because the size of the chip will not increase. On the contrary, as technology advances, the industry expects the size of the chip to decrease. The industry needs a way to increase the number of chip channels without violating the chip size limit. In order to increase the number of input / output ports on a microchip that can be coupled to optical fibers in a feasible way, a method of setting more than one row of ports along the edge of the chip has been proposed.

[0013] According to some aspects of the present specification, a plurality of separate discrete optical ferrules are assembled along a thickness direction of the optical ferrule (e.g., the z-axis of the optical stack) to form a stack of optical ferrules. In some embodiments, the optical ferrules may be assembled in a removable manner (i.e., such that the optical ferrules can be disconnected from each other as needed). In some embodiments, the plurality of optical ferrules may include at least three separate discrete optical ferrules. In some embodiments, each of the optical ferrules may include a top surface and a bottom surface opposite the top surface, such that the top surface and the bottom surface define a thickness direction therebetween. In some embodiments, the optical ferrules in the stack of optical ferrules may be bonded together, held in place in the stack by mechanical features (e.g., one or more alignment features or engagement features), clamped together, or assembled in any suitable manner.

[0014] In some embodiments, the top surface may include a light redirecting member and a plurality of attachment areas for receiving and permanently attaching to a plurality of corresponding optical waveguides (e.g., optical fibers). In some embodiments, the attachment area of ​​each of the optical ferrules may include a plurality of grooves extending along the length of the optical ferrule. In some embodiments, each of the grooves may be configured to receive and permanently attach to a corresponding optical waveguide of the plurality of corresponding optical waveguides.

[0015] In some embodiments, the bottom surface may include an exit window. In some embodiments, when the optical waveguide is received and permanently attached to the attachment area, the central light ray is emitted by the optical waveguide and redirected by the light redirecting member, and then exits the optical ferrule through the exit window as an exit central light ray. In some embodiments, the central light ray emitted by the optical waveguide 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 by the optical waveguide is redirected by the light redirecting member at a redirection angle, wherein the variation in the redirection angle of the optical ferrule is 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 different optical ferrules may be such that the central light rays emitted by the optical ferrules may be substantially parallel).

[0016] In some embodiments, for each pair of adjacent stacked upper optical ferrules and lower optical ferrules in the plurality of stacked optical ferrules, the exit central light of the upper optical ferrule enters the lower optical ferrule through the top surface of the lower optical ferrule, and exits from the lower optical ferrule through the exit window of the lower optical ferrule. In some embodiments, each exit central light of each optical ferrule in the plurality of optical ferrules may exit the exit window of the lowermost optical ferrule at a different position of the exit window of the lowermost optical ferrule.

[0017] In some embodiments, a central light ray emitted by a light guide can be incident on a light redirecting member of an optical ferrule along a substantially straight incident ray, and the incident ray for each of the optical ferrules can be offset relative to each other along a common length direction (e.g., an x-axis) of the optical ferrule. In some embodiments, a central light ray emitted by a light guide can be incident on the light redirecting member of the optical ferrule at corresponding spaced-apart incident positions on the light redirecting member of the optical ferrule, such that in a top view viewed along a thickness direction of the optical ferrule, they form a two-dimensional array of incident positions of the light redirecting member of the optical ferrule, such that no incident position in the array overlaps with any of the other incident positions in the array.

[0018] In some embodiments, each of the optical ferrules may further include a pair of opposing side walls that are spaced apart along a width direction (e.g., y-axis) of the optical ferrule, extend along a length direction (e.g., x-axis) of the optical ferrule, and join a top surface and a bottom surface of the optical ferrule.

[0019] In some embodiments, each of the optical ferrules may further include an input member such that when the optical waveguide is received and permanently attached to the attachment region, a central light ray emitted by the optical waveguide enters the optical ferrule through the input member of the optical ferrule. In such embodiments, the incoming central light ray may be incident on the light redirecting member along a first direction, and then the light redirecting member may redirect the incident central light ray to be along 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 of the optical ferrules, the incident central light ray and the redirected central light ray may form an angle between about 30 degrees and 150 degrees therebetween.

[0020] In some embodiments, the exit window of at least one of the optical ferrules may include an anti-reflective coating disposed on the exit window to reduce reflection of incident light having a wavelength 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%.

[0021] According to some aspects of the present specification, each of the optical ferrules in the plurality of optical ferrules includes a light redirecting member configured to receive one or more central light rays emitted from corresponding one or more optical waveguides attached to the optical ferrule in a first direction, and redirect the one or more received central light rays into one or more redirected central light rays in a different second direction. In some embodiments, the redirected central light rays exit the optical ferrule as one or more exit central light rays through an exit window of the optical ferrule. In some embodiments, each of the one or more exit central light rays of each of the optical ferrules passes through a different exit position of an exit window of the same optical ferrule in the plurality of optical ferrules.

[0022] In some embodiments, the plurality of optical ferrules may be permanently or removably assembled along a thickness direction of the optical ferrule (e.g., along the z-axis) to form a stack of optical ferrules. In some such embodiments, the optical ferrules in the plurality of optical ferrules may be substantially identical, and the optical ferrules may be offset relative to each other at least along a common length direction of the optical ferrule (e.g., the x-axis).

[0023] In some embodiments, an optical communication system may include a plurality of optical ferrules, such as the plurality of optical ferrules described herein, disposed on a substrate. In some embodiments, the substrate may include a plurality of optical elements (e.g., gratings, silicon photonic chips, sensors, etc.). In some embodiments, each of the one or more exit center rays of each of the optical ferrules passing through different exit positions 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 of the plurality of optical ferrules may be substantially identical to at least one other of the plurality of optical ferrules.

[0024] According to some aspects of the present specification, an optical stack includes a plurality of optical ferrules assembled along a thickness direction (e.g., z-axis) of an optical ferrule. In some embodiments, each of the optical ferrules is configured such that a plurality of central light rays emitted by 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 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 of the optical ferrules along the first direction may exit the optical stack through the exit surface of the optical stack after passing through each of the other optical ferrules disposed between the optical ferrule and the exit surface. In some embodiments, the optical ferrules in the plurality of optical ferrules may be substantially identical. In some embodiments, at least one of the optical ferrules may be different from at least one other of the optical ferrules.

[0025] In some embodiments, the optical ferrules in each pair of adjacent optical ferrules in the plurality of optical ferrules may be offset relative to each other along both the length direction (eg, x-axis) and the width direction (eg, opposite y-axis) of the optical ferrules.

[0026] Now turning to the attached figure, Figure 1 is a perspective view of an optical stack 100 including a plurality of individual optical ferrules, and FIG. 2A to FIG. 2C Provided Figure 1 Various exploded views of the optical stack 100 of FIG. Figure 1 and FIG. 2A to FIG. 2C for the following discussion.

[0027] In some embodiments, the optical stack 100 may include a plurality of individual discrete optical ferrules 10, 20. In some embodiments, the optical ferrules 10, 20 may be provided along the thickness direction of the optical ferrules 10, 20 (e.g., Figure 1 z-axis shown) may be removably or permanently assembled to form the optical stack 100.

[0028] In some embodiments, each of the optical ferrules may include a top surface 11, 21 and a bottom surface 14, 24 opposite the top surface 11, 21 (see also Figure 2C In some embodiments, the top surface 11, 21 and the bottom surface 14, 24 may define a thickness direction of the optical ferrule 10, 20 therebetween (corresponding to Figure 1 In some embodiments, the top surface 11, 21 may include a plurality of attachment areas 12, 22 for receiving and permanently attaching to a plurality of corresponding optical waveguides 30, 40 (see also Figure 2A ). In some embodiments, the top surfaces 11 , 12 may also include light redirecting members 13 , 23 .

[0029] In some embodiments, each of the optical ferrules 10, 20 may further include a pair of opposing side walls 17a, 17b (see Figure 1 and Figure 2A ), the pair of opposite side walls are arranged along the width direction of the optical ferrule 10, 20 (for example, Figure 1 and Figure 2A The optical ferrules 10 and 20 are spaced apart from each other (eg, the y-axis shown), extend along the length direction (eg, the x-axis) of the optical ferrules 10 and 20, and join the top surfaces 11 and 12 and the bottom surfaces 14 and 24 of the optical ferrules 10 and 20.

[0030] In some embodiments, the bottom surface 14, 24 of the optical ferrule 10, 20 may include an exit window 15, 25 (see Figure 2C ). In some embodiments, Figure 2B As shown, when the optical waveguides 30 , 40 are received and permanently attached to the attachment areas 12 , 22 , the central light 34 emitted by the optical waveguides 30 , 40 is redirected by the light redirecting members 13 , 23 into redirected central light 33 and exits the optical ferrules 10 , 20 through the exit windows 15 , 25 .

[0031] In some embodiments, the exit window 15, 25 of at least one of the optical ferrules 10, 20 may include an anti-reflection coating 80 disposed on the exit window to reduce reflection of incident light having a wavelength 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%.

[0032] In some embodiments, each of the optical ferrules 10, 20 may also include an input member 18 (eg, a surface adjacent to the end of the optical fiber 30, 40, see Figure 2A) such that when the optical waveguides 30, 40 are received and permanently attached to the attachment regions 12, 22, the central light 34 emitted by the optical waveguides 30, 40 enters the optical ferrule 10, 20 through the input member 18.

[0033] In some embodiments, the incident central light ray 34 and the redirected central light ray 33 can form an angle α1 between about 30 and 150 degrees. In some embodiments, the redirected central light ray 33 emitted by 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.

[0034] It should be noted that, for the sake of clarity, Figure 2B Only the center ray 34 of the top optical ferrule 10 is shown. However, the optical ferrule 20 may have a similar center ray emitted by the optical waveguide 40 and redirected by the light redirecting member 23, exiting through the exit window 25. Furthermore, when the optical stack 100 is fully assembled, the redirected center ray 33 exiting from the exit window 15 of the optical ferrule 10 will pass through the optical ferrule 20 and exit through an exit location on the bottom surface 24 on the optical ferrule 20. This concept is shown in more detail in at least FIG. 5 elsewhere herein. It should also be noted that although Figure 1 and FIG. 2A to FIG. 2C The examples shown employ two optical ferrules (optical ferrule 10 and optical ferrule 20 ), but embodiments according to the present specification may include any suitable number of optical ferrules, such as 3, or 4, or 5, or 6. These examples are not intended to be limiting.

[0035] FIG. 3A to FIG. 3B It is shown how individual optical ferrules in an optical stack, such as optical stack 100 of the previous figures, may be offset relative to each other. Figure 3A is a front view of optical stack 100, and Figure 3B is a top view of the optical stack 100 (Note: For clarity, Figure 3B The main bodies of the optical ferrules 10 and 20 are omitted).

[0036] In some embodiments, multiple separate discrete optical ferrules (e.g., Figure 3A 10, 20) can form an optical stack 100. In some embodiments, when the optical waveguide (e.g., Figure 1 The optical waveguides 30, 40) are received and permanently attached to the attachment area (e.g., Figure 1 When the optical waveguides 30 and 40 are attached to the optical ferrule 10 and the optical ferrule 20, the central light emitted by the optical waveguides 30 and 40 can be along a substantially straight incident line (e.g., line 16 of the optical ferrule 10 and line 26 of the optical ferrule 20, along Figure 3A y-axis as shown) is incident on the light redirecting members 13, 23 of the corresponding optical ferrules 10, 20, such that the incident rays 16, 26 of the optical ferrules 10, 20 are offset relative to each other along the common length direction of the optical ferrules 10, 20 (e.g., along Figure 1 That is, incident ray 16 may be offset in the x-direction relative to incident ray 26 (i.e., further into the page or further out of the page). Figure 3B This is most evident in FIG. 1 , which presents a top view of incident rays 16 and 26, showing that Figure 3B Incident rays 16 and 26 are shown offset in the x-direction.

[0037] In some embodiments, the central light rays emitted by the optical waveguides 30, 40 may be incident on the light redirecting members 13, 23 of the optical ferrules 10, 20 at corresponding spaced apart incident positions (e.g., incident positions 16a to 16h of incident ray 16 and incident positions 26a to 26h of incident ray 26). In some embodiments, in a top view (e.g., Figure 3B ), the incident positions 16a to 16h and 26a to 26h may form a two-dimensional array 60, wherein none of the incident positions 16a to 16h, 26a to 26h in the array 60 overlaps with any other incident position in the array 60. That is, FIG. 3A to FIG. 3B In the embodiment embodied in FIG. 1 , the incident rays 16 and 26 (and correspondingly, the incident positions 16 a to 16 h, 26 a to 26 h) may be at Figure 3A and Figure 3B The offset is shown in both the x-direction and the y-direction. Additionally, due to the stacked nature of the optical ferrules 10 and 20, the incident rays 16 and 26 may also be offset in the z-direction or thickness direction.

[0038] Figure 4 is similar to Figure 3A 1 is a front view of an embodiment of an optical stack 100a that is an embodiment of an optical stack 100, but having a third optical ferrule 70 in addition to the optical ferrules 10 and 20. Similar to the optical ferrules 10 and 20, in some embodiments, the optical ferrule 70 may have an incident ray 76 defined by incident positions 76a through 76h. Each of the incident positions 76a through 76h represents an incident point defining a substantially straight incident ray 76 of a central light ray incident on the light redirecting member 73 of the optical ferrule 70.

[0039] In some embodiments, the optical ferrules 10, 20, 70 in each pair of adjacent optical ferrules may be arranged along the length direction of the optical ferrules 10, 20, 70 (eg, Figure 4 x-axis shown) and width direction (e.g., Figure 4For example, the optical ferrule 10 may be offset from the optical ferrule 20 so that the incident positions 16a to 16h of the optical ferrule 10 are at Figure 4 The incident positions 26a to 26h of the optical ferrule 20 are offset in both the x-direction and the y-direction. Similarly, the optical ferrule 20 may be offset from the optical ferrule 70 such that the incident positions 26a to 26h of the optical ferrule 20 are offset in both the x-direction and the y-direction. Figure 4 The optical ferrule 70 is offset from the incident positions 76 a to 76 h in both the x-direction and the y-direction.

[0040] In some embodiments, at least one of the plurality of optical ferrules may be substantially identical to at least one other of the plurality of optical ferrules. In some embodiments, at least one of the plurality of optical ferrules may be structurally different from at least one other of the plurality of optical ferrules. In some embodiments, an optical ferrule in the plurality of optical ferrules may be substantially identical to at least one other of the plurality of optical ferrules. Figure 4 The optical ferrule 10 may have an offset in the y-direction of the optical stack 100, the offset alternating from a first offset value to a second offset value for each optical ferrule in the optical stack 100. For example, the offset in the width direction of the optical ferrule 10 may be substantially similar to the offset in the width direction of the optical ferrule 70 (i.e., both are offset by the same first offset value), while the offset in the width direction of the intermediate optical ferrule 20 may be a different second value. Figure 4 1 and 2. This is shown by a vertical dashed line drawn through the entry point 16h of the optical ferrule 10 and the entry point 76h of the optical ferrule 70, which in turn passes between the entry points 26g and 26h of the optical ferrule 20.

[0041] Figure 5A and Figure 5B It shows how individual optical ferrules in an optical stack can be offset relative to each other in multiple dimensions. Figure 5A for Figure 4 A side view of the optical stack 100A, and Figure 5B The top plan view shows Figure 4 The incident rays are 16, 26 and 76. Figure 5B In the illustrated optical stack 100A, the optical ferrules 10, 20, and 70 are shown as being arranged in a longitudinal direction of the optical ferrule (eg, Figure 5A are offset from each other in the x-direction).

[0042] In some embodiments, when the optical waveguide 30, 40, 90 is received and permanently attached to the attachment area of ​​the optical core 10, 20, 70, the central light ray 31, 41, 91 can be emitted by the corresponding optical waveguide and redirected by the light redirecting member 13, 23, 73, and then exit from the corresponding optical core through the corresponding exit window as the exit central light ray 32, 42, 92 in the second (redirecting) direction 52.

[0043] In some embodiments, for each pair of adjacent stacked upper optical ferrules 10, 20 and lower optical ferrules 20, 70 in a plurality of stacked optical ferrules, the exit central light 32, 42, 92 of the upper optical ferrule enters the lower optical ferrule through the top surface of the lower optical ferrule, and exits from the lower optical ferrule through the exit window of the lower optical ferrule. That is, the exit central light of each optical ferrule can enter the optical ferrule immediately below it (if any). In one example, the exit central light 32 exits from the optical ferrule 10, enters and passes through the optical ferrule 20, then enters and passes through the optical ferrule 70, and exits from the optical stack 100A from the bottom surface 74 of the bottommost optical ferrule 70. In some embodiments, each exit central light ray 32, 42, 92 of each optical ferrule 10, 20, 70 of the plurality of optical ferrules exits the exit window 75 of the lowermost optical ferrule 70 at a different position 25a, 25b, 25c.

[0044] 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 a plurality of optical elements 51a, 51b, 51c. In some embodiments, each of the one or more exit central light rays 32, 42, 92 of each of the optical ferrules 10, 20, 70 passing through different exit positions 25a, 25b, 25c of the exit window 75 of the same optical ferrule 70 may be optically coupled to a different optical element 51a, 51b, 51c of the plurality of optical elements.

[0045] Figure 5B The alignment of incident rays 16, 26, and 76 (and corresponding incident positions 16a-16h, 26a-26h, and 76a-76h) in one embodiment of the optical stack 100A is shown in top plan view. In some embodiments, incident rays 16, 26, and 76 can be offset from each other in both the x-direction (i.e., the length direction of the ferrule) and the y-direction (i.e., the width direction). If each of the incident positions shown (in Figure 5B ) represents the incident point on the corresponding light redirecting member of the optical ferrule, and assumes that all redirected (outgoing) central rays (e.g., Figure 5AThe exiting central light rays 32, 42 and 92) are substantially parallel, then the corresponding pattern of the optical element 51 can be arranged on the substrate 51 so that each optical element 51 receives the corresponding Figure 5B The two-dimensional array of optical elements 51 on the substrate 50 (corresponding to Figure 5B The two-dimensional array of incident points shown) can enable the substrate to have a larger number (more densely patterned) of input / output ports.

[0046] at last, Figure 6 An additional view of one embodiment of an optical stack is provided, which provides another perspective angle of the optical stack 100 and additional detail and clarity. Figure 6 Many of the elements shown have been discussed in the figures and description elsewhere herein and, unless specifically stated otherwise, should be assumed to function the same as previously described herein.

[0047] In some embodiments, the optical stack 100 may include a plurality of optical ferrules, such as the optical ferrule 10 and the optical ferrule 20 (or, in other embodiments, any suitable number of optical ferrules). Each optical ferrule 10, 20 may receive and be attached to a plurality of optical waveguides 30, 40 (e.g., a plurality of optical fibers). In some embodiments, each of the optical ferrules 10, 20 may also include an input member (e.g., an input surface) 18 such that when the optical waveguides 30, 40 are received and permanently attached to the attachment region, a central light ray 31, 41 emitted by the optical waveguides 30, 40 enters the optical ferrule 10, 20 through the input member 18 such that an incoming central light ray 34 incident on the light redirecting member 13, 23 along the incident ray 16, 26 and the first direction 31a is redirected by the light redirecting member 13, 23 along a different second direction 31b. In some embodiments, the redirected central light ray 33, 43 exits the optical ferrule 10, 20 through the exit window 15, 25 of the corresponding optical ferrule 10, 20 as the exit central light ray 32, 42. In some embodiments, each of the one or more exit central light rays 32, 42 of each of the optical ferrules passes through a different exit position 25a, 25b of the exit window 25 of the same optical ferrule 20. It should be noted that the exit central light ray 32 exits the optical ferrule 10 through the exit window 15 and then enters the optical ferrule 20 through the top surface 21 of the optical ferrule 20 before passing out of the optical stack 100 through the exit window 25 of the optical ferrule 20.

[0048] Terms such as "about" will be understood by one of ordinary skill in the art in the context of use and description in this specification. If it is not clear to one of ordinary skill in the art in the context of use and description in this specification that "about" should be used to express the amount of feature size, quantity, and physical properties, then "about" will be understood to mean within 10% of the specified value. A quantity given as about a specified value may be exactly the specified value. For example, if it is not clear to one of ordinary skill in the art in the context of use and description in this specification, a quantity having a value of about 1 means that the quantity has a value between 0.9 and 1.1, and the value may be 1.

[0049] One of ordinary skill in the art will understand terms such as "substantially" in the context of use and description in this specification. If the use of "substantially equal" in the context of use and description in this specification is unclear to one of ordinary skill in the art, "substantially equal" will refer to approximately the situation of approximately as described above. If the use of "substantially parallel" in the context of use and description in this specification is unclear to one of ordinary skill in the art, "substantially parallel" will refer to within 30 degrees of parallel. In some embodiments, directions or surfaces described as being substantially parallel to each other may be within 20 degrees or within 10 degrees of parallel, or may be parallel or nominally parallel. If the use of "substantially aligned" in the context of use and description in this specification is unclear to one of ordinary skill in the art, "substantially aligned" will refer to alignment within 20% of the width of the object of alignment. In some embodiments, the objects described as being substantially aligned may be aligned within 10% or within 5% of the width of the object of alignment.

[0050] All references, patents, and patent applications cited above are hereby incorporated by reference in their entirety in a consistent manner. In the event of inconsistencies or conflicts between an incorporated reference portion and the present application, the information in the foregoing description shall prevail.

[0051] Unless otherwise indicated, the description of the elements in the drawings should be understood to be equally applicable to the corresponding elements in the other drawings. Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that the specific embodiments shown and described may be replaced with a variety of alternative and / or equivalent implementations without departing from the scope of the present disclosure. The present application is intended to cover any modification or variation of the specific embodiments discussed herein. Therefore, the present disclosure is intended to be limited only by the claims and their equivalents.

Claims

1. A plurality of separate discrete optical ferrules, the plurality of separate discrete optical ferrules being assembled along the thickness direction of the optical ferrule to form a stack of the optical ferrules, each of the optical ferrules comprising: a top surface comprising a light redirecting member and a plurality of attachment areas for receiving and permanently attaching to a plurality of corresponding optical waveguides; and a bottom surface, the bottom surface being opposite to the top surface and including an exit window, the top surface and the bottom surface defining the thickness direction of the optical ferrule therebetween, so that when the optical waveguide is received and permanently attached to the attachment area, a central light ray emitted by 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, Wherein, for each pair of adjacently stacked upper optical ferrules and lower optical ferrules in the plurality of stacked optical ferrules, the exit central light of the upper optical ferrule enters the lower optical ferrule through the top surface of the lower optical ferrule, and exits from the lower optical ferrule through the exit window of the lower optical ferrule, and wherein each exit central light of each optical ferrule in the plurality of optical ferrules exits the exit window of the lowermost optical ferrule at a different position of the exit window of the lowermost optical ferrule.

2. The plurality of individual discrete optical ferrules of claim 1, wherein the optical ferrules are removably assembled.

3. The plurality of individual discrete optical ferrules of claim 1 , wherein when the optical waveguide is received and permanently attached to the attachment region of each of the optical ferrules, the central light ray emitted by the optical waveguide is incident on the light redirecting member of the optical ferrule along a substantially straight incident ray, and wherein the incident rays of the optical ferrules are offset relative to each other along a common length direction of the optical ferrules.

4. The plurality of individual discrete optical ferrules of claim 1 , wherein when the optical waveguide is received and permanently attached to the attachment region of each of the optical ferrules, the central light rays emitted by the optical waveguide are incident on the light redirecting member of the optical ferrule at corresponding spaced apart incident positions on the light redirecting member of the optical ferrule, such that in a top view viewed along the thickness direction of the optical ferrule, a two-dimensional array of the incident positions of the light redirecting member of the optical ferrule is formed, wherein no incident position in the array overlaps with any of the other incident positions in the array.

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

6. The plurality of individual discrete optical ferrules of claim 1, wherein the attachment region of each of the optical ferrules is configured to receive and permanently attach to the corresponding optical waveguide, wherein the optical waveguide comprises an optical fiber.

7. The plurality of individual discrete optical ferrules of claim 1 , wherein each of the optical ferrules further comprises a pair of opposing side walls spaced apart along a width direction of the optical ferrule, extending along a length direction of the optical ferrule, and joining the top surface and the bottom surface of the optical ferrule.

8. The plurality of individual discrete optical ferrules of claim 1 , wherein the attachment region of each of the optical ferrules comprises a plurality of grooves extending along a length of the optical ferrule, each of the grooves being configured to receive and permanently attach to a corresponding optical waveguide of the plurality of corresponding optical waveguides.

9. The plurality of individual discrete optical ferrules of claim 1 , wherein each of the optical ferrules further comprises an input member, such that when the optical waveguide is received and permanently attached to the attachment region, the central light ray emitted by the optical waveguide enters the optical ferrule through the input member of the optical ferrule, the entered central light ray is incident on the light redirecting member along a first direction, the light redirecting member redirects the incident central light ray to be along a different second direction, the redirected central light ray exits the optical ferrule through the exit window of the optical ferrule as the exit central light ray.

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

11. The plurality of individual discrete optical ferrules of claim 1 , wherein the central light ray emitted by the optical waveguide is redirected by the light redirecting member at an angle of at least 40 degrees.

12. The plurality of individual discrete optical ferrules of claim 1, wherein the central light ray emitted by the optical waveguide is redirected by the light redirecting member at a redirection angle, and wherein the redirection angle of the optical ferrule varies by less than about 10 degrees.

13. The plurality of individual discrete optical ferrules of claim 1, wherein the exit window of at least one of the optical ferrules comprises an anti-reflection coating disposed on the exit window to reduce reflection of incident light having a wavelength greater than about 500 nm by at least 1%.

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

16. The plurality of optical ferrules of claim 15, wherein the optical ferrules in the plurality of optical ferrules are substantially identical, and wherein the optical ferrules are offset relative to each other at least along a common length direction of the optical ferrules.

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

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

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

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

21. The optical stack of claim 19, wherein the optical ferrules in each pair of adjacent optical ferrules in the plurality of optical ferrules are offset relative to each other in both a length direction and a width direction of the optical ferrules.

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