Optical fiber attachment device

Abstract

To provide an optical fiber (FO) attachment that is flexible sufficient to attach an FO sensor to various different base materials, for example, a concrete, metal, stone construction and lumber.SOLUTION: An optical fiber mold device has a first portion that includes a base layer having a longitudinal-direction characteristic part configured to receive an optical fiber. At least one second portion is disposed over the base layer. The second portion has a center wall part, and a front end wall part and a rear end wall part. The center wall part, the front end wall part and the rear end wall part form a mold cavity. At least one first hole is disposed in the mold cavity, and this hole is configured to allow a mold material for entering the mold cavity. At least one second hole in the mold cavity is configured to allow air displaced by the mold material to exit the mold cavity.SELECTED DRAWING: Figure 1A

Description

Background Art

[0001] Optical fiber (FO) sensors can be used to detect parameters such as strain, temperature, pressure, current, voltage, chemical composition, and vibration. FO sensors are attractive components because they are thin, lightweight, highly sensitive, robust against harsh environments, and not affected by electromagnetic interference (EMI) and electrostatic discharge. FO sensors can be configured to simultaneously measure multiple parameters distributed in space with high sensitivity in a multiplexed configuration on a long optical fiber cable. An example of a method to achieve this is the fiber Bragg grating (FBG) sensor. FBG sensors are formed by periodic modulation of the refractive index along a finite length (typically a few millimeters) of the core of an optical fiber. This pattern reflects a wavelength (referred to as the Bragg wavelength) determined by the periodicity of the refractive index profile. The Bragg wavelength is sensitive to external stimuli (such as strain and / or temperature) that change the periodicity of the grating and / or the refractive index of the fiber. Therefore, FBG sensors rely on detecting small wavelength changes that occur in response to the target stimulus. In some implementations, FO sensors can be attached to a structure and operate to detect parameters related to the integrity of the structure, such as strain, temperature, and vibration.

Summary of the Invention

[0002] Embodiments described herein include an optical fiber mold device comprising a first portion including a base layer having a longitudinal feature configured to receive an optical fiber. At least one second portion is disposed above the base layer. The second portion includes a central wall portion and a front end wall portion and a rear end wall portion. The central wall portion, the front end wall portion, and the rear end wall portion form a mold cavity. At least one first hole is disposed in the mold cavity and is configured to allow mold material to enter the mold cavity. At least one second hole in the mold cavity is configured to allow air displaced by the mold material to exit the mold cavity.

[0003] The optical fiber molded device comprises a first portion including a base layer having a longitudinal feature configured to receive an optical fiber. Two or more second portions are spaced apart on the base layer. Each second portion includes a central wall portion, as well as a front end wall portion and a rear end wall portion. The central wall portion, the front end wall portion, and the rear end wall portion form a mold cavity. At least one first hole is provided in the mold cavity, configured to allow the mold material to enter the mold cavity. At least one second hole is provided in the mold cavity, configured to allow air displaced by the mold material to exit the mold cavity. A tunnel portion is provided between the two second portions. The tunnel portion is configured to house at least one optical sensor disposed on the optical fiber.

[0004] The method includes positioning an optical fiber in a longitudinal feature portion of the base layer of a molded device. The molded device includes a first portion comprising a base layer having a longitudinal feature portion configured to receive an optical fiber. A second portion is disposed on the base layer. The second portion includes a central wall portion, as well as a front wall portion and a rear wall portion. The central wall portion, the front wall portion, and the rear wall portion form a mold cavity. At least one first hole is disposed in the mold cavity, and this hole is configured to allow mold material to enter the mold cavity. At least one second hole is disposed in the mold cavity, and this hole is configured to allow air displaced by the mold material to exit the mold cavity. The method includes placing the molded device and the optical fiber on a structural surface and injecting mold material into the first hole of the molded device. [Brief explanation of the drawing]

[0005] Throughout this specification, refer to the attached drawings. [Figure 1A]This is a perspective view of a molded device according to several embodiments. [Figure 1B] Figure 1A is a bottom view of the molded device. [Figure 1C] Figure 1A is a bottom view of the molded device. [Figure 1D] Figure 1A is an illustrative cross-sectional view of the molded device. [Figure 1E] Figure 1A is an illustrative cross-sectional view of the molded device. [Figure 2] This is a perspective view of a molded device, including notches in the front and rear walls, according to several embodiments. [Figure 3] This is a perspective view of a mold device having a forward-extending portion and a rearward-extending portion according to several embodiments. [Figure 4] This is a top view of a molded device having a curved front end wall and a curved rear end wall according to several embodiments. [Figure 5A] This is a side cross-sectional view of a mold device having an adhesive disposed on the lower surface of the mold device, according to several embodiments. [Figure 5B] Figure 5A is a bottom view of the molded device. [Figure 5C] This is a side cross-sectional view of a mold device having an adhesive disposed on the lower surface of the lateral extension portion of the mold device, according to several embodiments. [Figure 5D] Figure 5C is a bottom view of the molded device. [Figure 6A] This is a side cross-sectional view of a mold device having an adhesive disposed on the upper surface of the laterally extending portion of the mold device, according to several embodiments. [Figure 6B] Figure 6A is a bottom view of the molded device. [Figure 6C] Figure 6A is a perspective view of the molded device. [Figure 7] This is a perspective view of a mold device having a fluid adhesive disposed on the upper surface of the laterally extending portion of the mold device, according to several embodiments. [Figure 8A]This is a bottom view of a mold device having adhesive disposed on the bottom surfaces of the laterally extending portion, the forward extending portion, and the rearward extending portion, according to several embodiments. [Figure 8B] Figure 8A is a side cross-sectional view of the molded device. [Figure 9A] This is a bottom view of a mold device having adhesive tape disposed on the upper surface of the mold device, according to several embodiments. [Figure 9B] Figure 9A is a perspective view of the molded device. [Figure 10] This is a top view of a molded device having an engagement feature portion disposed on a base layer, according to several embodiments. [Figure 11A] Several embodiments of molded devices arranged in a rosette pattern are shown. [Figure 11B] Figure 11A shows typical dimensions of the molded device. [Figure 12] Several embodiments of a molded device arranged in a biaxial pattern are shown. [Figure 13A] This is a flowchart illustrating a process using a molding device according to several embodiments. [Figure 13B] This is a flowchart illustrating a process using a molding device according to several embodiments. [Figure 14] The process of attaching a molded device according to several embodiments is shown. [Figure 15A] The process for attaching a molded device to a structure according to several embodiments is shown, and the molded device has a forward feature portion and a backward feature portion used to pre-strain the optical fiber. [Figure 15B] The process for attaching a molded device to a structure according to several embodiments is shown, and the molded device has a forward feature portion and a backward feature portion used to pre-strain the optical fiber. [Figure 15C]Shows a process of attaching a mold device to a structure according to some embodiments, the mold device having front and rear features used to impart pre-strain to an optical fiber. [Figure 15D] Shows a process of attaching a mold device to a structure according to some embodiments, the mold device having front and rear features used to impart pre-strain to an optical fiber. [Figure 15E] Shows a process of attaching a mold device to a structure according to some embodiments, the mold device having front and rear features used to impart pre-strain to an optical fiber. [Figure 15F] Shows a process of attaching a mold device to a structure according to some embodiments, the mold device having front and rear features used to impart pre-strain to an optical fiber. [Figure 15G] Shows a process of attaching a mold device to a structure according to some embodiments, the mold device having front and rear features used to impart pre-strain to an optical fiber. [Figure 15H] Shows a process of attaching a mold device to a structure according to some embodiments, the mold device having front and rear features used to impart pre-strain to an optical fiber. [Figure 15I] Shows a process of attaching a mold device to a structure according to some embodiments, the mold device having front and rear features used to impart pre-strain to an optical fiber. [Figure 15J] Shows a process of attaching a mold device to a structure according to some embodiments, the mold device having front and rear features used to impart pre-strain to an optical fiber. [Figure 15K] Shows a process of attaching a mold device to a structure according to some embodiments, the mold device having front and rear features used to impart pre-strain to an optical fiber. [Figure 15L] The process for attaching a molded device to a structure according to several embodiments is shown, and the molded device has a forward feature portion and a backward feature portion used to pre-strain the optical fiber. [Figure 15M] The process for attaching a molded device to a structure according to several embodiments is shown, and the molded device has a forward feature portion and a backward feature portion used to pre-strain the optical fiber. [Figure 15N] The process for attaching a molded device to a structure according to several embodiments is shown, and the molded device has a forward feature portion and a backward feature portion used to pre-strain the optical fiber. [Figure 15O] The process for attaching a molded device to a structure according to several embodiments is shown, and the molded device has a forward feature portion and a backward feature portion used to pre-strain the optical fiber. [Figure 15P] The process for attaching a molded device to a structure according to several embodiments is shown, and the molded device has a forward feature portion and a backward feature portion used to pre-strain the optical fiber. [Figure 15Q] The process for attaching a molded device to a structure according to several embodiments is shown, and the molded device has a forward feature portion and a backward feature portion used to pre-strain the optical fiber. [Figure 16] This is a top view of a molded device useful for mounting optical fibers and / or sensors, according to several embodiments, such that the sensors are substantially strain-isolated from the structure. [Figure 17A] The diagrams show molded devices suitable for mounting optical fibers, including strain-free temperature sensors and / or span sensors, according to several embodiments. [Figure 17B] The diagrams show molded devices suitable for mounting optical fibers, including strain-free temperature sensors and / or span sensors, according to several embodiments.

[0006] Drawings are not necessarily to scale. Similar numbers used in drawings refer to similar components. However, it should be understood that the use of numbers to refer to components in a given drawing is not intended to limit components in another drawing labeled with the same number. [Modes for carrying out the invention]

[0007] Optical fiber (FO) sensors can be deployed on various types of structures, such as bridges, roads, railways, and electrical devices such as transformers, to monitor the structural integrity of the structure. Embodiments disclosed herein include devices and methods for mounting FO sensors to structures. Embodiments described herein can be used to protect FO sensors from the environment. In some embodiments, the disclosed devices facilitate mounting FO sensors to structures in such a way that strain from the structure is transmitted to the sensors. In some embodiments, the disclosed devices can be used to mount FO sensors to structures in such a way that the sensors are isolated from strain within the structure. The approaches discussed herein provide mounting of FO sensors that are sufficiently flexible to mount FO sensors to a variety of different substrates, such as concrete, metal, masonry, and wood. The described devices and methods improve the repeatability of mounting so that optical fibers can be mounted in the same shape and / or length, and / or so that at least some or most of the FO sensors have the same pre-strain once mounted. The disclosed mounting approaches can be implemented quickly and easily to facilitate the deployment of multiple FO sensors to structures. The adhesive mounting approaches described below eliminate the need to drill holes in or weld structures.

[0008] Figure 1A shows a top perspective view of the optical fiber molded device 100, and Figures 1B and 1C show examples of bottom views of the optical fiber molded device 100 according to several embodiments. Figures 1D and 1E show end section views of the molded device 100. The molded device 100 includes a first portion 101, which includes a base layer 110 having a longitudinal feature 111 configured to receive an optical fiber 190 (not shown in Figures 1A to 1C, but shown in section in Figures 1D and 1E). The longitudinal feature 111 may include, for example, openings, grooves, and / or channels within the base layer 110. In some embodiments, the longitudinal feature 111 may extend along the entire length of the base layer 110. The longitudinal feature 111 may extend substantially parallel to and / or close to the central longitudinal axis 191 of the device 100. It should be noted that the base layer 110 does not need to have a polygonal shape as shown in Figures 1A to 1E. The base layer may have one or more curved sides, for example, as shown in Figure 16.

[0009] The molded device 100 includes at least one second portion 102 disposed adjacent to the base layer 110. The second portion 102 includes a central wall portion 120, as well as a front end wall portion 128 and a rear end wall portion 129. The molded cavity 103 can be configured to accommodate an optical fiber sensor, such as a fiber Bragg grating (FBG) sensor, within the molded cavity 103. The molded device 100 may be formed as a single-piece structure.

[0010] At least one first hole 121 is located in the mold cavity 103, configured to allow a molding material, such as epoxy, to enter the mold cavity 103. For example, in some configurations, the first hole 121 may be located at the top of the central wall 120, approximately midway between the front wall 128 and the rear wall 129. The molding device 100 may include a plug 121p that seals the hole 121 after the mold cavity 103 is filled, so that the molding material, such as epoxy, does not substantially leak out after the molding material is injected.

[0011] There is at least one second hole 122 into the mold cavity 103, configured to allow air displaced by the mold material to exit the mold cavity 103. The molding device 100 may include a plug 122p that can be used to seal the hole 122 after filling the mold cavity 103 so that the mold material does not substantially leak out of the hole 122 after the injection of the mold material. According to some implementations, at least one second hole 122 may be located in the front end wall 128 and / or the rear end wall 129, for example, near the top of the front end wall 128 and / or the rear end wall 129. The second hole 122 (or more holes) may be positioned in defined locations to allow for homogeneous filling of the mold cavity 103 with minimal voids. The design of the mold cavity 103 facilitates a defined “layered” flow of the mold material. After the mold material has cured, the optical fiber and / or FO sensor are firmly held within the mold cavity 103.

[0012] The molded device 100 provides a permanent housing for optical fibers and / or FO sensors. When the molded material enters the mold cavity, it comes into contact with the optical fibers and / or FO sensors within the mold cavity. After the molded material is injected into the mold cavity of the molded device and subsequently cured, the molded device and molded material seal and protect the fibers and / or FO sensors from environmental stresses such as humidity, ultraviolet (UV) radiation, and / or animal intrusion.

[0013] As shown in Figure 1A, the front end wall 128 and / or rear end wall 129 of the mold cavity may be substantially flat. As will be discussed below, in some implementations, the front end wall and / or rear end wall of the mold cavity may be curved. Figure 1A shows a mold cavity 103 in which the central wall 120 is curved, for example, forming a semi-cylindrical shape. As will be discussed below, the central wall may have curved or substantially flat sides. In some embodiments, the central wall may have a substantially flat top.

[0014] Optionally, the base layer of the molded device includes lateral extensions, forward extensions, and / or rearward extensions. In some configurations, as shown in the top perspective view of Figure 1A, the base layer 110 includes one or more extensions 131, 132, 141, 142 that extend away from the mold cavity walls 120, 128, 129. As shown, the lateral extensions 131, 132 extend away from the central wall 120, the forward extension 141 extends away from the front end wall 128, and the rearward extension 142 extends away from the rear end wall 129.

[0015] As is most commonly seen in the bottom views of Figures 1B and 1C and the cross-sectional views of Figures 1D and 1E, the base layer 110 has a first main surface 110a and an opposing second main surface 110b, with a mold cavity 103 disposed between the first main surface 110a and the second main surface 110b. Figure 1C shows an example where the first main surfaces 110a and 110b are partially within the mold cavity 127, and a portion 125 of the mold cavity 127 is open.

[0016] In embodiments including extensions, each lateral extension 131, 132 has a first surface 131a, 132a and opposing second surfaces 131b, 132b. The forward extension 141 has a first surface 141a and opposing second surface 141b. The rearward extension 142 has a first surface 142a and opposing second surface 142b. As will be discussed in more detail below, any or all of these surfaces of the mold device 100 may be suitable for the application of adhesives to attach the mold device to a structure. The adhesive may be disposed on one or more of the following: the second main surface 110b of the base layer, the first surfaces 131a, 132a of the lateral extensions, the second surfaces 131b, 132b of the lateral extensions, the first surface 141a of the forward extension, the second surface 141b of the forward extension, the first surface 142a of the rearward extension, and the second surface 142b of the rearward extension.

[0017] As shown in Figure 1B, one or more of the bonding surfaces 110b, 131a, 131b, 132a, 132b, 141a, 141b, 142a, 142b of the molded device 100 may include capillary channels 155 configured to enhance the bonding of the adhesive to facilitate attachment to the structural surface. The capillary channels 155 can also enhance strain transmission from the structure to the optical fiber and / or optical fiber sensor.

[0018] Suitable materials useful for forming the first portion 101 and / or the second portion 102 of the molded device 100 include, for example, plastics, metals, silicones, and / or urethanes. The material of the first portion 101 and / or the second portion 102 of the molded device 100 may be rigid or flexible, allowing the molded device 100 to be installed on a substantially flat or non-flat surface. The material of the first portion 101 and / or the second portion may be transparent to the wavelengths of visible light and / or curing radiation. The adhesive used to bond the molded device 100 to the structural surface may be a fast-setting adhesive to allow for the rapid attachment of optical fibers and / or optical fiber sensors to the structure. Suitable adhesive materials include double-sided adhesive tapes, single-sided adhesive tapes, laminated adhesive superglue (cyanoacrylate), and / or epoxy.

[0019] Referring to Figures 1D and 1E, the width W1 of the central wall portion may be in the range of approximately 2 to 10 mm, for example, approximately 6 mm; the width W2 of the lateral extension portion may be in the range of approximately 2 to 10 mm, for example, approximately 5 mm; and the radius of curvature R of the central wall portion may be in the range of approximately 1 to 5 mm, for example, approximately 3 mm. The thickness of the mold material may be in the range of approximately 0.25 mm to approximately 0.75 mm, for example, approximately 0.5 mm. These dimensional ranges are also applicable to other embodiments.

[0020] Referring now to Figure 2, perspective views of the molding device 200 according to several embodiments are shown.

[0021] The molded device 200 includes a first portion 201 comprising a base layer 210 having lateral extensions 231, 232. The base layer 210 has a first main surface 210a and an opposing second main surface 210b within the mold cavity 203. The lateral extensions 231, 232 each have a first main surface 231a, 232a and an opposing second main surface 231b, 232b. Adhesives may be disposed on surfaces 210b, 231a, 231b, 232a, 232b to bond the molded device 200 to the structure, as will be presented in more detail below.

[0022] The base layer 210 includes a longitudinal feature portion 211 configured to receive the optical fiber 190. The longitudinal feature portion 211 may include a longitudinal opening, channel, or groove extending longitudinally along the base layer 210. As shown in the embodiment of Figure 2, the longitudinal feature portion 211 may include, for example, a groove extending along the entire length L1 of the base layer 210.

[0023] The second portion 202 of the mold device 200 has a central wall portion 220 together with a substantially flat front wall portion 228 and a substantially flat rear wall portion 229. As shown in Figure 2, the sides of the central wall portion 220 may be substantially flat, and the top of the central wall portion 220 may be curved. Alternatively, the top of the central wall portion may also be substantially flat. The second portion 202 covers a portion of the base layer 210 and at least partially covers the longitudinal feature portion 211 of the base layer 210.

[0024] The first portion 201 and the second portion 202 form a mold cavity 203. A first hole 221 is located in the mold cavity 203, configured to receive the mold material into the mold cavity 203. In many configurations, the first hole 221 is located near the top of the central wall portion 220. The hole 221 may be located at any convenient location within the second portion 102 to facilitate the injection of the mold material, for example, midway along the length of the central wall portion and midway along the width of the central wall portion 220, as shown. There is a second hole 222 into the mold cavity 203, which allows air displaced by the mold material to exit the mold cavity 203. In some cases, there may be multiple holes. For example, the first hole may be located on the wall portion 228 and the second hole may be located on the wall portion 229. The hole 222 can be located at any convenient location within the second portion 102 to facilitate the escape of air during the injection of the mold material. For example, in some embodiments, the second hole 222 may be located near the central apex of the front end wall portion 228 and / or the rear end wall portion 229.

[0025] The length of the mold device 200 may be in the range of approximately 1 cm to approximately 4 cm, for example, approximately 2.5 cm. The diameter of the first hole 221 may be in the range of approximately 1 mm to 5 mm, for example, approximately 3 mm. The diameter of the second hole 222 may be in the range of approximately 0.5 mm to approximately 1.0 mm, for example, approximately 0.8 mm.

[0026] The mold device 300 shown in the embodiment of Figure 3 is similar in some embodiments to that of the mold device 200 shown in Figures 2A and 2B. However, the mold device 300 includes a base layer 310 having optional forward-extending portions 341 and rear-extending portions 342 extending from a front end wall portion 228 and a rear end wall portion 229, respectively. The forward-extending portion 341 includes a first main surface 341a and an opposing second main surface 341b. The rear-extending portion 342 includes a first main surface 342a and an opposing second main surface 342b. As will be further discussed herein, adhesive may be applied to one or more of the first main surfaces 341a, 342a and the second main surfaces 341b, 342b in order to bond and attach the mold device 300 to a structure.

[0027] The forward-extending portions 341 and the rear-extending portions 342 may include feature portions 351 and 352 that extend at least partially through the extended portions 341 and 342 of the base layer 310. These recesses are suitable for housing adhesive that secures the optical fiber to the molded device 300 and / or structure. For example, in some embodiments, the recesses 351 and 352 may include wells that do not extend through both the first main surfaces 341a, 342a and the second main surfaces 341b and 342b. Alternatively, the recesses may be holes that extend through both the first main surfaces 341a, 342a and the second main surfaces 341b and 342b. The recesses 351 and 352 may be used to secure the optical fiber 190 to provide pre-tension during installation of the optical fiber 190 and the molded device 300, as will be discussed below.

[0028] Figure 4 is a top view of a mold device 400 according to several embodiments. The mold device 400 includes a first portion 401 and a second portion 402. The first portion includes a base layer 410 having lateral extensions 431, 432 and forward extensions 441 and rearward extensions 442. The second portion 402 includes a central wall 420, a front wall 428 and a rear wall 429. The lateral extensions 431, 432 of the base layer 410 extend from the central wall 420, the forward extension 441 of the base layer 410 extends from the front wall 428, and the rearward extension 442 of the base layer 410 extends from the rear wall 429. Note that in this particular embodiment, the central wall 420, the front wall 428 and the rear wall 429 are all curved.

[0029] The first hole 421, passing through the central wall 420, is located near the top of the central wall 420 and is configured to receive the mold material. The second hole 422 is located within the rear end wall 429, near the top of the rear end wall. In many implementations, the position of the second hole 422 may be lower along the z-axis than the position of the first hole 451. In some cases, the second hole 422 may include multiple second holes. For example, holes may be located on the wall 428, and holes may be located on the wall 429.

[0030] The longitudinal feature portion 411 includes a longitudinal opening, groove, and / or channel extending longitudinally within the base layer 410 along the y-axis. In this embodiment, the forward-extending portion 428 includes a hole 451 extending through the forward-extending portion layer 428. The rearward-extending portion 429 includes a hole 452 extending through the rearward-extending portion layer 429. Note that in this embodiment, the holes 451 and 452 in the forward-extending portion 428 and the rearward-extending portion 429 merge with the longitudinal opening 411. According to various embodiments, the holes 451 and / or holes 452 may include wells containing holes with walls.

[0031] Figures 5A and 5B illustrate molded device 500-1 according to several embodiments. Figure 5A is a side cross-sectional view of molded device 500-1 and structure 199. Figure 5B shows a bottom view of molded device 500-1. Molded device 500-1 includes a first portion 501-1 which includes a base layer 510-1 that does not have a lateral extension, a forward extension, or a backward extension. A longitudinal feature portion 511 is configured to receive an optical fiber 190. A second portion 502-1 is disposed on the base layer 510-1 such that the second portion 502-1 and the base layer 510-1 form a mold cavity 503-1. As shown in Figures 5A and 5B, the base layer 510-1 has a first main surface 510-1a adjacent to the mold cavity 503-1 and a second main surface 510-1b facing it. An adhesive 560, such as epoxy, super glue (cyanoacrylate), and / or double-sided adhesive tape, is disposed on the second main surface 510-1b of the base layer 510-1 on both sides of the mold cavity 503-1. When the mold device 500-1 is placed on the structure 199, the adhesive 560 is located between the surface of the structure 199 and the second surface 510-1b of the base layer 510-1. The adhesive 560 is selected to form a bond between the mold device 500-1 and the structure 199.

[0032] Figure 5C is a side cross-sectional view of the molded device 500-2 and structure 199 according to several embodiments. Figure 5D shows a bottom view of the molded device 500-2. The molded device 500-2 includes a first portion 501-2, which includes a base layer 510-2 having lateral extensions 531, 532. The longitudinal feature portion 511 is configured to receive and secure the optical fiber 190. The second portion 502-2 is disposed on the base layer 510-2 such that the second portion 502-2 and the base layer 510-2 form a mold cavity 503-2. The second portion 502-2 includes a first hole 521, as shown. As is best seen in the bottom view of Figure 5D, the lateral extension 531 has a second main surface 531b, and the lateral extension 532 has a second main surface 532b. In the illustrated embodiment, an adhesive 560, such as epoxy, super glue (cyanoacrylate), or double-sided adhesive tape, is disposed on the second main surfaces 531b, 532b of the extended portions 531, 532. When the mold device 500-2 is placed on the structure 199, the adhesive 560 is located between the surface of the structure 199 and the second surfaces 531b, 532b of the extended portions 531, 532. The adhesive 560 is selected to form a bond between the mold device 500-2 and the structure 199.

[0033] Figures 6A to 6C show embodiments in which an adhesive tape 660, for example, a single-sided adhesive tape, is disposed on the first surfaces 631a, 632a of the laterally extending portions 631, 632 of the mold device 600. The adhesive tape 660 extends across the first surfaces 631a, 632a of the laterally extending portions and extends above the surface of the structure 199, thus adhering the mold device 600 to the structure 199. Figure 6A shows a side cross-sectional view of the mold device 600. Figure 6B shows a bottom view of the mold device 600, and Figure 6C provides a perspective view of the mold device 600 and the structure 199. The mold device 600 includes a first portion 601 which includes a base layer 610 having laterally extending portions 631, 632. The second portion 602 is disposed on the base layer 610 such that the second portion 602 and the base layer 610 together form a mold cavity 603, as described above. The second portion 620 includes a first hole 621 in the central wall, as shown. As best seen in the bottom view of Figure 6B, the lateral extension 631 has a second main surface 631b, and the lateral extension 632 has a second main surface 632b. The second main surfaces 631b and 632b are in contact with the surface of the structure. The longitudinal feature portion 611 is configured to receive and secure the optical fiber 190.

[0034] As is best seen in the perspective view of Figure 6C, the lateral extension 631 has a first main surface 631a, and the lateral extension 632 has a first main surface 632a. In the illustrated embodiment, an adhesive 660, which may be a single-sided tape, is disposed on the first main surfaces 631a, 632a of the extensions 631, 632 and extends beyond the extensions 631, 632 onto the surface of the structure 199. The adhesive 660 is selected to form a bond between the surface of the structure 199 and the mold device 600, thereby firmly holding the mold device 600 to the structure 199.

[0035] Figure 7 shows a mold device 700 according to several embodiments. In this particular embodiment, a fluid adhesive such as superglue (cyanoacrylate) or epoxy is used to bond the mold device 700 to the structure 199. The adhesive 760 is disposed on the upper surfaces 731a, 732a of the lateral extensions 731, 732 of the mold device 700 and extends outward above a portion of the surface of the structure 199.

[0036] Figures 8A and 8B show a mold device 800 according to an embodiment. Figures 8A and 8B show a bottom view and a side cross-sectional view of the device 800, respectively. The mold device 800 shown in Figures 8A and 8B has several features that are substantially the same as those of the mold device 500-2 illustrated above in Figures 5C and 5D. In Figures 8A and 8B, the same reference numerals are used to refer to substantially similar features shown in Figures 5C and 5D. Figure 8A shows a bottom view of the mold device 800. Figure 8B is a side cross-sectional view of the mold device 800.

[0037] The molding device 800 differs from device 500-2 in that it includes a forward extension 841 and a rear extension 842, which extend away from the front wall 528 and the rear wall 529, respectively. The adhesive 860 is disposed on the forward extension 841 and the rear extension 842. Each of the forward extension 841 and the rear extension 842 includes a forward feature 851 and a rear feature 852 within the extension 531, 532, respectively. In this particular embodiment, the feature 851, 852 are holes passing through the extension 531, 532. As shown in the cross-sectional view of Figure 8B, the hole 852 includes a lip 852a. Optionally, one or both holes include a lip 852a configured to hold the adhesive within the hole after the adhesive has been deposited within the hole 852.

[0038] As best seen in the cross-sectional view of Figure 8B, each extension 841, 842 includes a first main surface 841a, 842a adjacent to the front wall 528 and the rear wall 529, and an opposing second surface 841b, 842b. The adhesive 860 is disposed on the second main surfaces 531b, 532b of the lateral extensions 531, 532, such that the adhesive 860 extends over the surfaces and 531b, 532b of the lateral extensions 531, 532, and over the second main surfaces 841b, 842b of the front extension 841 and the rear extension 842. Additional adhesive is indicated on the second surface 842b of the rear extension 842.

[0039] The molding device 900 shown in Figures 9A and 9B has several features that are substantially the same as those of the molding device 600 shown in Figures 6A to 6C. In Figures 9A and 9B, the same reference numerals are used to refer to substantially similar features shown in Figures 6A to 6C. Figure 9A shows a bottom view of the molding device 900. Figure 9B is a perspective view of the molding device 900.

[0040] The mold device 900 differs from device 600 in that it includes a forward-extending portion 941 and a rear-extending portion 942 that extend away from the front wall portion 628 and the rear wall portion 629, respectively. Each of the forward-extending portion 941 and the rear-extending portion 942 includes a feature portion 951, for example, a well or hole 952 within the extension portion layer.

[0041] As best seen in Figure 9B, each extension 941, 942 includes a first main surface 941a, 942a adjacent to the front wall 628 and the rear wall 629, and an opposing second surface 941b, 942b. The adhesive 960 is disposed on the first main surfaces 631a, 632a of the lateral extensions 631, 632, such that the adhesive 960 extends over the surfaces and 631a, 632a of the lateral extensions 631, 632, and also over the first main surfaces 941a, 942a of the front extension 941 and the rear extension 942. The adhesive, which may be a single-sided tape, extends outward from the extensions 631, 632, 941, 942 to bond the mold device 900 to the structure 199, up to the surface of the structure 199.

[0042] According to some implementations, two or more molded devices can be used together to form a sensing cluster. This technique is useful, for example, for sensing parameters in multiple dimensions. A particularly useful configuration is a biaxial configuration in which two sensors are positioned along two orthogonal axes (see, for example, Figure 12). Another useful configuration is a rosette configuration in which two sensors are positioned along two orthogonal axes and a third sensor is positioned at an angle of approximately 45 degrees to the orthogonal axis (see, for example, Figure 11A). When sensors are used in a cluster, the shape of the molded devices can be designed to facilitate the alignment of multiple molded devices. Multiple molded devices can be used to bond multiple fiber sensors in a specific, distinct configuration. Engaging features on the molded devices can result in the orientation of the molded devices and / or the locking of the molded devices together.

[0043] Figure 10 shows a molded device 1000 that includes engaging features useful for aligning and / or interlocking multiple molded devices into a pattern. The molded device 1000 comprises a first portion 1001 including a base layer 1010 having lateral extensions 1031, 1032 and forward extensions 1041 and rear extensions 1042. A second portion 1002 is disposed on the base layer 1010, and the second portion 1002 includes a central wall portion 1020 and forward wall portions 1028 and rear wall portions 1029. According to some embodiments, the base layer 1010 forms a polygon having substantially straight edges 1081, 1082, 1083, 1084, 1085, 1086. Some of the edges, for example, edges 1081, 1082 are oriented at 90 degrees to each other, and some edges are inclined, for example, oriented at an angle different from 90 degrees. For example, edge 1085 is oriented at a 45-degree angle to edge 1081, and edge 1086 is oriented at a 45-degree angle to edge 1083. When multiple mold devices are used together in a pattern, the inclined edges can be used to create mitered corners; see, for example, Figure 12.

[0044] In some embodiments, the edges may include additional engaging features that integrally orient and / or lock the molded device. For example, along edges 1081 and 1086, molded device 1000 includes a projection 1071 adapted to receive a recess 1072 disposed on the edges 1083 and 1085 of another molded device. Other engaging features may include inclined sides, grooves, and / or other features that serve to integrally orient, connect, and / or lock the molded device. According to various embodiments, the configuration shown in Figure 10 may include one or more longitudinal openings, grooves, channels, and / or temporary epoxy openings similar to features 951 and 952.

[0045] Figure 11A shows cluster 1100 of mold devices 1100-1, 1100-2, and 1100-3 arranged in a rosette pattern. The slanted edge 1186-2 of mold device 1100-2 is positioned adjacent to the straight edge 1183-1 of device 1100-1. The slanted edge 1185-2 of mold device 1100-2 is positioned adjacent to the straight edge 1181-3 of device 1100-3. The arrangement of edges 1183-1, 1186-2, 1185-2, and 1181-3 forms a mitered corner between mold devices 1100-1, 1100-2, and 1100-3.

[0046] Figure 11B provides another example of mold devices 1100-1, 1100-2, and 1100-3 arranged in a rosette pattern with typical dimensions. The length L2 of mold devices 1100-1 and 1100-3 is in the range of approximately 2 to 10 cm, for example, approximately 6 cm. The length L3 of mold device 1100-2 is in the range of approximately 2 to 10 cm, for example, approximately 5.7 cm. The width W6 of mold devices 1100-1, 1100-2, and 1100-3 is in the range of approximately 0.5 cm to approximately 2.5 cm, for example, approximately 1.7 cm. The center-to-center distance L4 between the front feature portion and the rear feature portion is in the range of approximately 2 cm to approximately 6 cm, for example, approximately 4 cm. The center-to-center distance L5 between the rear feature portion and the first hole in the second portion is in the range of approximately 1 cm to approximately 3 cm, for example, approximately 2 cm. The distance L6 between the front edge and the center of the front feature is in the range of approximately 0.5 mm to approximately 2 mm, for example, approximately 1 mm. Figure 12 shows cluster 1200 of mold devices 1200-1 and 1200-2 arranged in a biaxial pattern. The inclined edge 1286-2 of mold device 1200-2 is positioned adjacent to the inclined edge 1285-1 of device 1200-1. The arrangement of edges 1286-2 and 1285-1 forms a mitered corner between mold devices 1200-1 and 1200-2.

[0047] Figure 13A is a flowchart illustrating a method for using a molding device to attach an optical fiber to the surface of a structure. The method in Figure 13A is suitable when the longitudinal feature includes a longitudinal opening within the base layer. According to this method, the optical fiber is positioned on the surface of the structure (1305). The molding device is positioned on the surface of the structure so that the optical fiber is received by the longitudinal opening (1315). The molding device is bonded to the surface of the structure by adhesive disposed on the top and / or bottom surfaces of the molding device (1325). Optionally, the optical fiber is pre-tensioned (1335) before the molding material is injected into the molding device (1345).

[0048] Figure 13B is a flowchart illustrating a method for using a molding device to attach an optical fiber to the surface of a structure. In this particular embodiment, the optical fiber is positioned in the longitudinal feature portion of the molding device (1310). The molding device and the optical fiber are placed on the surface of the structure (1320). The molding device is bonded to the surface of the structure by adhesive disposed on the top and / or bottom surfaces of the molding device (1330). Optionally, the optical fiber is pre-tensioned (1340) before the molding material is injected into the molding device (1350).

[0049] Figure 14 shows clusters of mold devices 1401, 1402, and 1403 that hold optical fibers 190-1, 190-2, and 190-3 in a rosette pattern. The central axis of optical fiber 190-3 and mold device 1403 is aligned along the x-axis, the central axis of optical fiber 190-1 and mold device 1401 is aligned along the y-axis perpendicular to the x-axis (θ2 = 90 degrees), and the central axis of optical fiber 190-2 and mold device 1402 is aligned at an angle of θ1 = 45 degrees with respect to the x-axis. In this embodiment, optical fibers 190-1, 190-2, and 190-3 are fixed within the mold cavities of mold devices 1401, 1402, and 1403 by mold material injected through a first hole in each mold device 1401, 1402, and 1403. Each of the molded devices 1401, 1402, and 1403 is fixed to the surface of structure 199 by adhesives disposed on the top and / or bottom surfaces of devices 1401, 1402, and 1403. The optical fibers 190-1, 190-2, and 190-3 are attached to the structure at two or more attachment points by epoxy or other types of adhesive. Optical fiber 190-1 is attached to the surface of attachment points 1495-1a and 1495-1b, optical fiber 190-2 is attached at attachment points 1495-2a and 1495-2b, and optical fiber 190-3 is attached at attachment points 1495-3a and 1495-3b. The optical fibers 190-1, 190-2, and 190-3 may be optionally pre-strained before being attached to structure 199 at mounting points 1495-1a, 1495-1b, 1495-2a, 1495-2b, 1495-3a, and 1495-3b.

[0050] Figures 15A to 15Q illustrate methods for attaching optical fibers to a structure in a rosette pattern using molded devices, according to several embodiments. Referring here to Figure 15A, first, optical fiber 1591 is positioned on the structure 199. As shown in Figure 15B, the first molded device is positioned above the optical fiber 1591. A longitudinal opening 1511 in the molded device 1501 receives the optical fiber 1591. The first molded device 1501 is positioned so that the optical fiber is exposed by a first hole 1551 in the forward-extending portion of the first molded device 1501 and by a second hole 1552 in the rear-extending portion of the first molded device 1501. The first molded device 1501 is attached to the surface of the structure 199 by adhesive disposed on the top and / or bottom surfaces of the molded device 1501. An additional molded device 1503 is positioned on the surface. The inclined corners of the additional molding device 1503 help to orient the second molding device 1503 at an angle of approximately 45 degrees relative to the first molding device 1501.

[0051] Figure 15C shows the arrangement after a fluid adhesive such as epoxy 1560 is deposited in a hole 1551 in the forward-extending portion of the first molded device 1501, and the epoxy is cured. Note that the epoxy used in hole 1551 does not need to be the same adhesive used to fix the molded device to the surface of the structure. Epoxy 1560 bonds one end of the optical fiber 1591 to the surface of the structure 199. Tension is applied to the optical fiber 1591 in the direction of arrow 1596, as shown in Figure 15D. While tension is applied along direction 1596, epoxy is deposited in a second hole 1552 in the rearward-extending portion of the first molded device 1501, as shown in Figure 15E, and the epoxy is cured. The cured epoxy in the first hole 1551 and the second hole 1552 maintains the tension of the optical fiber 1591 at a predetermined pre-tension value. The tension applied to the optical fiber 1591 along direction 1596 is released as shown in Figure 15F.

[0052] Referring now to Figure 15G, in the next process step, the optical fiber 1592 is positioned on the structure 199. The second molding device 1502 is positioned above the optical fiber 1592. A longitudinal opening 1511 in the molding device 1502 receives the optical fiber 1592. The second molding device 1502 is positioned so that the optical fiber 1592 is exposed by the first hole 1551 and the second hole 1552 in the second molding device 1502. The inclined corner of the third molding device 1503 helps to orient the second molding device 1502 at an angle of approximately 45 degrees relative to the third molding device 1503.

[0053] Figure 15H shows the arrangement after epoxy 1560 has been deposited in hole 1551 in the forward-extending portion of the second mold device 1502, and the epoxy is cured. The epoxy 1560 bonds one end of the optical fiber 1592 to the surface of the structure 199. Tension is applied to the optical fiber 1592 in the direction of arrow 1597, as shown in Figure 15I. While tension is applied along direction 1597, epoxy is deposited in the second hole 1552 in the rearward-extending portion of the second mold device 1502, as shown in Figure 15J, and the epoxy is cured. The cured epoxy in the first hole 1551 and the second hole 1552 of the second mold device 1502 maintains the tension of the optical fiber 1592 at a predetermined pre-tension value. The tension applied to the optical fiber 1592 along direction 1596 is released.

[0054] In the next step, the third molded device is rotated outward from the plane of the structural surface (Figure 15K) to allow the third optical fiber 1593 to be positioned on the surface of the structure 199 (Figure 15L). The third molded device 1503 is then rotated in the reverse direction toward the surface so that the longitudinal opening 1511 within the third molded device 1503 receives the optical fiber 1593 (Figure 15M). The third molded device 1503 is positioned so that the optical fiber 1593 is exposed by the first hole 1551 and the second hole 1552 within the third molded device 1503.

[0055] Figure 15N shows the arrangement after epoxy 1560 has been deposited in hole 1551 in the forward-extending portion of the third mold device 1503, and the epoxy is cured. The epoxy 1560 bonds one end of the optical fiber 1593 to the surface of the structure 199. Tension is applied to the optical fiber 1593 in the direction of arrow 1598, as shown in Figure 15O. While tension is applied along direction 1598, epoxy is deposited in the second hole 1552 in the rearward-extending portion of the third mold device 1503, as shown in Figure 15P, and the epoxy is cured. The cured epoxy in the first hole 1551 and the second hole 1552 of the third mold device 1503 maintains the tension of the optical fiber 1593 at a predetermined pre-tension value. The tension applied to the optical fiber 1593 along direction 1598 is released. The molding material is injected through hole 1561 into the mold cavities of the first molding device 1501, the second molding device 1502, and the third molding device 1503. Note that the molding material may be epoxy and does not have to be the same material used to secure the optical fibers 1591, 1592, and 1593, and / or to attach the molding devices 1501, 1502, and 1503 to the structure 199.

[0056] The embodiments described above are suitable for fixing optical fibers, such as optical fiber sensors, including optical fiber Bragg grating (FBG) sensors. FBG sensors may be sensitive to strain within a structure. The approaches discussed herein can facilitate the mechanical coupling of FBG sensors to a structure so that strain within the structure is transmitted to the sensor.

[0057] Conversely, some implementations involve joining optical fibers containing FBG sensors in a manner such that strain within the structure is not substantially transmitted to the sensors. A substantially strain-isolated FBG sensor can be used, for example, to measure temperature near a structure.

[0058] Figure 16 is a top view of a molded device 1600 suitable for mounting an optical fiber containing an FBG temperature sensor to a structure such that the temperature sensor is substantially strain-isolated from the structure 199. In this implementation, the molded device 1600 includes a first portion 1601 which includes a base layer 1610 having two curved sides 1681, 1683 and two straight sides 1682, 1684. A longitudinal feature portion 1611, such as a longitudinal opening or longitudinal groove, extends along the base layer 1610.

[0059] Two second sections 1602-1 and 1602-2 are positioned above the first section 1601. Each second section 1602-1 and 1602-2 includes a central wall section 1620, a front end wall section 1628, and an end wall section 1629. The base layer 1610 and the second section 1602-1 form the first mold cavity 1603-1. The base layer 1610 and the second section 1602-2 form the second mold cavity 1603-2. A first hole 1621 passing through the central wall section 1620 of the second sections 1602-1 and 1602-2 is configured to allow the molding material to be injected into the mold cavities 1603-1 and 1603-2. Second holes (not shown) are provided in the second sections 1602-1 and 1602-2 to allow air displaced by the mold material to exit the mold cavities 1603-1 and 1603-2.

[0060] A tunnel section 1604 is positioned between the first section 1602-1 and the second section 1602-2. The tunnel section 1604 is configured to receive and at least partially enclose the optical fiber sensor, so that the sensor is substantially mechanically isolated from strain within the tunnel section 1604. In some embodiments, the tunnel section 1604 does not include holes for mold injection and / or air venting. The relatively small, defined tunnel section 1604 housing the optical fiber temperature sensor serves to reduce the effects on the temperature sensor from pre-strain and to reduce the possibility of the temperature sensor being accidentally "bonded" to the structure by stains, coatings, paints, etc.

[0061] The base layer 1610 includes lateral extensions 1631, 1632 that extend away from the central wall 1620 of the second portions 1602-1, 1602-2. A forward extension 1641 extends away from the forward wall 1628 of the first portion 1602-1. A hole 1651 configured to receive epoxy is located within the forward extension 1641. A rearward extension 1642 extends away from the rear wall 1629 of the second portion 1602-2. A hole 1652 configured to receive epoxy is located within the rearward extension 1642.

[0062] The base layer 1610 has a first main surface adjacent to the second portions 1602-1 and 1602-2 located inside the mold cavities 1603-1 and 1603-2, and an opposing second main surface. The lateral extensions 1631 and 1632 have a first main surface adjacent to the second portions 1602-1 and 1602-2, and opposing second surfaces 1631b and 1632b. The forward extension 1641 and the rearward extension 1642 have a first main surface adjacent to the second portions 1602-1 and 1602-2, and an opposing second surface. As described above, adhesive can be disposed on one or more of these surfaces to bond the mold device 1600 to the structural surface as described above.

[0063] Figure 17A is a top view and Figure 17B is a side view of another molded device 1700 suitable for mounting optical fibers including strain-free temperature sensors and / or span sensors. In this example, the sensors do not have to be directly mounted to the structure but are housed and protected within a sealed molded structure. In some cases, two corners of the sensor are mounted to the mold instead of being directly mounted to the structure.

[0064] The molded device 1700 includes a first portion 1701 which includes a base layer 1710 having two first opposing substantially straight sides 1781, 1783 and two second opposing substantially straight sides 1782, 1784. A longitudinal feature portion 1711, such as a longitudinal opening or a longitudinal groove, extends along the base layer 1710.

[0065] Two second sections 1702-1 and 1702-2 are positioned above the first section 1701. Each second section 1702-1 and 1702-2 includes a central wall section 1720, a front end wall section 1728, and an end wall section 1729. The base layer 1710 and the second section 1702-1 form the first mold cavity 1703-1. The base layer 1710 and the second section 1702-2 form the second mold cavity 1703-2. A first hole 1721 passing through the central wall section 1720 of the second sections 1702-1 and 1702-2 is configured to allow the molding material to be injected into the mold cavities 1703-1 and 1703-2. Second holes (not shown) are provided in the second sections 1702-1 and 1702-2 to allow air displaced by the mold material to exit the mold cavities 1703-1 and 1703-2.

[0066] A tunnel section 1704 is positioned between a first section 1702-1 and a second section 1702-2. The tunnel section 1704 is configured to receive and at least partially enclose the optical fiber sensor, so that the sensor is substantially protected from environmental disturbances (e.g., wind, rain, etc.) within the tunnel section 1704. According to various configurations, the temperature sensor is substantially mechanically isolated from strain within the tunnel section 1704, and the span sensor is pre-strained within the tunnel section 1704. In some embodiments, the tunnel section 1704 does not include holes for mold injection and / or air venting. The relatively small, defined tunnel section 1704 housing the optical fiber temperature sensor serves to reduce the effects of pre-strain on the temperature sensor and reduces the possibility of the temperature sensor and / or span sensor being accidentally "bonded" to the structure by stains, coatings, paints, etc.

[0067] The base layer 1710 includes lateral extensions 1731, 1732 that extend away from the central wall 1720 of the second portions 1702-1, 1702-2. A forward extension 1741 extends away from the forward wall 1728 of the first portion 1702-1. A hole 1751 configured to receive epoxy is located within the forward extension 1741. A rearward extension 1742 extends away from the rear wall 1729 of the second portion 1702-2. A hole 1752 configured to receive epoxy is located within the rearward extension 1742.

[0068] The base layer 1710 has a first main surface adjacent to the second portions 1702-1 and 1702-2 located inside the mold cavities 1703-1 and 1703-2, and a second main surface opposite to it. The lateral extensions 1731 and 1732 have a first main surface adjacent to the second portions 1702-1 and 1702-2, and a second surface opposite to it. The forward extension 1741 and the rearward extension 1742 have a first main surface adjacent to the second portions 1702-1 and 1702-2, and a second surface opposite to it. As described above, an adhesive can be disposed on one or more of these surfaces to bond the mold device 1700 to the structural surface as described above.

[0069] The molded devices described herein facilitate the definition of the shape, size, location, and / or quantity of adhesive used for bonding between the molded device and the structure. The disclosed approach for using the molded devices enables defined uniform strain transfer (within one sensor or between different sensors) by, for example, reducing air bubbles and / or voids within the molded material. The molded devices enable controlled bonding that can be implemented in automated, semi-automated, and / or manual fiber sensor installations using robots and / or installation tools. When installed as discussed herein, the molded devices protect the fiber optics and / or fiber sensors from environmental influences such as water ingress, chemical influences such as UV exposure and automobile exhaust, humidity, vibration, and the like.

[0070] In some embodiments, the type of adhesive and / or molding material used with the mold device may be configured to indicate that bonding has occurred and / or been performed correctly. For example, referring to Figure 8B, a first type of adhesive may be used to bond the mold device 800 to the structural surface, a second type of adhesive may be used within the feature portions 851, 852, and a third type of adhesive may be injected into the hole 521 as molding material. In some embodiments, different types of adhesives may change color as indicators to facilitate installation once deposited. Adhesive materials used in different locations may be of different types. For example, the adhesive used to bond the mold device to the structure may be a fast-setting adhesive. The adhesive deposited in the feature portions 851, 852, and / or 521 may be, for example, a slower-setting adhesive.

[0071] While the subject matter is described in a language specific to structural features and / or methodological actions, it should be understood that the subject matter as defined in the attached claims is not necessarily limited to the specific features or actions described above. Rather, the specific features and actions described above are disclosed as representative forms of implementing the claims.

Claims

1. An optical fiber molded device, a first portion including a planar base layer having longitudinal features configured to receive an optical fiber, the longitudinal features disposed along a plane of the planar base layer, the planar base layer including a peripheral planar portion proximate the longitudinal features; at least one mold cavity disposed above the peripheral planar portion, the mold cavity comprising: A central wall portion; a front end wall and a rear end wall, the front end wall and the rear end wall forming the mold cavity; at least one first hole in the mold cavity configured to allow molding material to enter the mold cavity; at least one second hole in the mold cavity configured to allow air displaced by the molding material to exit the mold cavity; and at least one second portion comprising: An optical fiber mold device comprising:

2. The device of claim 1 , wherein the longitudinal feature comprises a longitudinal opening.

3. The device of claim 1 , wherein the longitudinal feature comprises a longitudinal groove.

4. The device of claim 1 , wherein the base layer includes first and second lateral extensions extending in opposite directions away from the central wall.

5. 5. The device of claim 4, wherein an adhesive is disposed on one or both surfaces of the first lateral extension and the second lateral extension (3).

6. The device of claim 1 further comprising a partial base layer, wherein the front and rear end walls, the central wall, the front and rear end walls, and the partial base layer form the mold cavity.

7. The base layer a forward extending portion extending in a direction away from the front end wall portion; a rearward extension extending in a direction away from the rear end wall, the longitudinal feature being longitudinally continuous through the forward extension and the rearward extension; The device of claim 1 further comprising:

8. The device of claim 7 , wherein an adhesive is disposed on a surface of at least one of the forward extension and the rearward extension.

9. a forward feature in the forward extension aligned with the longitudinal feature and configured to receive an adhesive to secure the optical fiber; 10. The device of claim 1, further comprising a rear feature in the rear extension aligned with the longitudinal feature and configured to receive an adhesive for securing the optical fiber.

10. The device of claim 9 , wherein one or both of the front feature and the rear feature include a hole through the base layer.

11. The device of claim 9 , wherein one or both of the front feature and the rear feature comprises a well.

12. The device of claim 11 , wherein the well has a lip that extends above the base layer.

13. 10. The device of claim 1, further comprising engagement features disposed on one or more edges of the base layer, each of the engagement features configured to engage with a matching engagement feature of another optical fiber mold device.

Images