LU506198B1 - Hermetically sealing hollow core optical fiber - Google Patents

Abstract

A device for dividing and hermetically sealing a hollow core optical fiber (HCF). The device comprising a channel sized to receive an HCF into the device, the HCF comprising a first portion and a second portion; a clamping means configured to clamp the first portion of the HCF received within the device; a biasing means configured to bias the second portion of the HCF away from the clamped first portion; a heating means configured to applying heat at a position along the inserted HCF, the position being between the first portion and the second portion of the HCF. The device can collapse a structure of the inserted HCF to hermetically seal the hollow core of the HCF from outside the HCF. The device can divide, at the heating position, the second portion of the HCF from the hermetically sealed first portion of the HCF.

Description

HERMETICALLY SEALING HOLLOW CORE OPTICAL FIBER LUS06198

BACKGROUND

[0001] An optical fiber, also known as an optical fibre, 1s a glass or plastic waveguide that can transmit light along a length of the optical fiber. An optical fiber may be used in a fiber-optic communication system where data is transmitted over long distances and at a high bandwidth. An optical fiber may take a large number of different forms and generally comprises a core surrounded by a cladding with a coating or buffer applied around an outer surface to mechanically protect the optical fiber and/or aid in light transmission along the optical fiber. An optical fiber may comprise a solid core such as the solid core optical fiber (SCF) illustrated in FIG. 1A or a hollow core such as the hollow core optical fibers (HCFs) illustrated in FIGs. 1B and 1C. An HCF guides light within a hollow region of the fiber. In HCF, a minor portion of the optical power may still propagate through solid fiber material.

[0002] FIG. 1A illustrates a cross section of an SCF. The SCF has an outer surface 11 and a solid core 110. Light travels axially through the solid core 110 along the

SCF. The solid core 110 is surrounded by cladding 111 to reduce light escaping the solid core.

[0003] FIG. 1B illustrates a cross section of a first HCF. The first HCF has an outer surface 12 that is an outer surface of a solid outer wall or cladding 120. Within the solid outer wall or cladding 120 is a hollow core 100. Additional structures within the first

HCF extend along the length of the HCF. In FIG. 1B, there are six inner tubular structures 121 and six intermediate tubular structures 122 extending along the length of the fiber.

The inner and intermediate tubular structures 121, 122 are substantially equally placed around the hollow core 100. Within each respective intermediate tubular structure 122 is an inner tubular structure 121 extending along the length of the HCF. The outer wall 12, inner tubular structure 121, and intermediate structure 122 run substantially parallel to each other along the length of the HCF. The space within the HCF illustrated as a void in the figure is filled with a fluid. The fluid may be an inert gas such as argon, nitrogen or atmospheric air. Advantages of HCF over SCF are that transmitted light travels faster along HCF (lower latency), higher powers can be transmitted over HCF and that light scatter is reduced in HCF therefore attenuation of light travelling along a fiber length is reduced. 1

MS Docket No. 413543-LU-NP

[0004] FIG. 1C illustrates a cross section of a second HCF. The second HCF has LU506198 an outer surface 13 that is formed from a solid outer body or cladding 130 surrounding a plurality of hollow structures 131, 132. A larger tubular hollow structure 131 extends along a central axis of the second HCF containing a hollow core of the HCF. Surrounding the larger tubular hollow structure 131 are a plurality of smaller tubular hollow structures 132 arranged uniformly. In other examples, not illustrated, an arrangement of hollow structures around a hollow core is not uniform.

[0005] HCF if malformed or if structurally damaged is susceptible to contamination from external factors. The external factors may be solid, liquid or gas. For example, if an HCF suffers physical damage either intentionally or unintentionally, water may ingress into the hollow core thereby contaminating the HCF and adversely affecting the performance of the HCF for transmitting light therethrough. A liquid, such as water, may move by capillary action along a structure in an HCF from a site of damage. Solids or gasses within a hollow core will increase the number of scattering points thereby increasing loss in the HCF. Contamination may also increase absorption within the HCF or may cause a change in waveguiding or an anti-resonant condition of the HCF that is detrimental to transmittal of light along the HCF.

SUMMARY

[0006] The following presents a simplified summary of the disclosure in order to provide a basic understanding to the reader. This summary is not intended to identify key features or essential features of the claimed subject matter nor is it intended to be used to limit the scope of the claimed subject matter. Its sole purpose is to present a selection of concepts disclosed herein in a simplified form as a prelude to the more detailed description that is presented later.

[0007] A device for hermetically sealing a hollow core optical fiber (HCF). The device comprises a channel sized to receive an HCF into the device; a clamping means configured to clamp a first portion of the HCF received within the device; a heating means configured to heat the HCF received within the device; and a biasing means configured to bias a second portion of the HCF received within the device away from the first portion of the HCF received within the device.

[0008] A method of hermetically sealing an HCF. The method comprising inserting an HCF into a device, the HCF comprising a first portion and a second portion; clamping the inserted first portion of the HCF to the device; biasing the second portion of the HCF away from the clamped first portion; applying heat at a position along the 2

MS Docket No. 413543-LU-NP inserted HCF, the position being between the first portion and the second portion of the LU506198

HCEF; collapsing a structure of the inserted HCF to hermetically seal the hollow core of the HCF from outside the HCF; and dividing, at the heating position, the second portion of the HCF from the hermetically sealed first portion of the HCF.

[0009] A portable device for dividing and hermetically sealing an HCF. The device comprising a channel sized to receive an HCF into the device, the HCF comprising a first portion and a second portion; a clamping means configured to clamp the first portion of the HCF received within the device; a biasing means configured to bias the second portion of the HCF away from the clamped first portion; a heating means configured to applying heat at a position along the inserted HCF, the position being between the first portion and the second portion of the HCF; and a battery configured to power the heating means. The device is operable to collapse a structure of the inserted

HCF to hermetically seal the hollow core of the HCF from outside the HCF. The device is operable to divide, at the heating position, the second portion of the HCF from the hermetically sealed first portion of the HCF.

[0010] Many of the attendant features will be more readily appreciated as the same becomes better understood by reference to the following detailed description considered in connection with the accompanying drawings.

DESCRIPTION OF THE DRAWINGS

[0011] The present description will be better understood from the following detailed description read in light of the accompanying drawings, wherein:

FIG. 1A illustrates a cross section of a solid core optical fiber;

FIG. 1B illustrates a cross section of a first hollow core optical fiber;

FIG. 1C illustrates a cross section of a second hollow core optical fiber;

FIG. 2 illustrates a schematic diagram of first exemplary device for hermetically sealing a hollow core optical fiber;

FIG. 3 illustrates a schematic diagram of a second exemplary device for hermetically sealing a hollow core optical fiber;

FIG. 4A illustrates a section of hollow core optical fiber with an unsealed end,

FIG. 4B illustrates the section of hollow core optical fiber with a sealed end;

FIG. 5 illustrates a third exemplary device for hermetically sealing a hollow core optical fiber;

FIG. 6 illustrates a flow diagram of a method for hermetically sealing a hollow core optical fiber; and 3

MS Docket No. 413543-LU-NP

FIG. 7 illustrates a schematic diagram of an exemplary computing-based system LU506198 for use with example devices.

Like reference numerals are used to designate like parts in the accompanying drawings.

DETAILED DESCRIPTION

[0012] The detailed description provided below in connection with the appended drawings is intended as a description of the present examples and is not intended to represent the only forms in which the present examples are constructed or utilized. The description sets forth the functions of the examples and the sequence of operations for constructing and operating the examples. However, the same or equivalent functions and sequences may be accomplished by different examples.

[0013] A device for dividing and hermetically sealing a HCF. The device comprising a channel sized to receive an HCF into the device, the HCF comprising a first portion and a second portion; a clamping means configured to clamp the first portion of the HCF received within the device; a biasing means configured to bias the second portion of the HCF away from the clamped first portion; a heating means configured to applying heat at a position along the inserted HCF, the position being between the first portion and the second portion of the HCF. The device is operable with minimal components ensuring a low cost for production and a portable nature so that the device can be distributed around a large number of sites and be transported to locations where dividing and hermetic sealing are required. For example, a bundle of 60 HCFs, for example in a cable, could have been laid and accidentally damaged. Sealing is also advantageous when the 'damage' is not accidental, for example when a long length of fiber or cable is divided into shorter lengths The open ends of HCF mean that contamination is possible and solids, liquids or gasses can consequently enter the HCFs, especially if the damage occurs in a wet environment. There is urgency to hermetically seal the damaged or potentially damaged fibers prior to later splicing to repair the damage. Sealing and dividing may be required up to or even more than 10 meters from a point of damage to avoid contamination of the remaining portion of HCF.

[0014] The device can collapse a structure of the inserted HCF to hermetically seal the hollow core of the HCF from outside the HCF. The device can divide, at the heating position, the second portion of the HCF from the hermetically sealed first portion of the

HCF. The device both sealing and dividing HCF reduces the likelihood of further unintended damage as merely hermetically sealing by heating an HCF to collapse the internal structure creates a point of weakness in the HCF as the sealed length will be less 4

MS Docket No. 413543-LU-NP flexible than the surrounding unsealed lengths. Further, additional work would be required LU506198 to later divide the sealed section. As such, sealing and dividing avoids this mid-fiber weak point in an HCF. In some examples, after hermetically sealing and before or after dividing, the first portion of a hermetically sealed HCF may be moved towards a heat source. This additional action enables additional heating for the sealed portion and localized melting. Surface tension of the localized melted length creates a rounded end comprising fiber material at the end of the hermetically sealed section. This rounded end acts to further protect the divided portion against further mechanical damage. Also, the rounded end acts to protect a user of the device by reducing the sharpness of a tip of a divided fiber end. The device may not include a camera for alignment of HCF prior to sealing or dividing. This lack of optical alignment can be advantageous as it eliminates the requirement to remove any coating or buffer on an HCF prior to sealing or dividing, because heated coating or buffer material can vaporize and impair or obscure a camera field of view. Therefore mechanical coating or buffer removal would be required prior to sealing or dividing, which would increase complexity and reduce the speed of emergency

HCF sealing after accidental damage has occurred.

[0015] FIG. 2 illustrates a schematic diagram of first exemplary device 20 for hermetically sealing a HCF 21. The HCF 21 extends into and through the device 20. In

FIG. 2, a first portion 211 of the illustrated HCF 21 is to be hermetically sealed and a second portion 212 of the HCF 21 is to be divided from the HCF 21 and, optionally, discarded. For example, the second portion 212 may have been damaged and/or contaminated. Two clamping mechanisms are illustrated: a first clamping means 22 for securing the first portion 211 and a second clamping means 23 for securing the second portion 212. While the FIG. 2 illustrates a simplified G-clamp icon, specialized fiber holders comprising a channel for receiving a fiber and a movable flap to hold the fiber may be used. Optionally, one or both clamping means 22, 23 is movable. The optional movement is indicated using the proximate arrow Al, A2 in the figure and movement does not have to be simultaneous. The one or both clamping means 22, 23 may be further movable in opposite directions. The clamping means 22, 23 may take many forms, for example, either or both the clamping means 22, 23 may be electro-mechanical and operated by control 26, or either or both clamping means may be mechanically or magnetic manually operated by mechanical movement of the device 20, such as by closing/opening of a lid of the device 20.

MS Docket No. 413543-LU-NP

[0016] Device 20 can generate a heating zone 24 using heating means. In this LU506198 example, heating means comprises a pair of electrodes 251, 252 controllable using controller 26. Controller 26 provides a potential difference between the two electrodes 251, 252, either in alternating current (A.C.) or direct current (D.C.), and the electricity arcs between the electrodes creating heat for the heating zone 24. The signal causing an arc can have various forms, such as pulse width modulation (PWM), a ramp, an impulse, etc. or a combination thereof. The arcing is controllable thereby a heating protocol can be implemented to control the amount and duration of heat generated at the heating zone 24.

Alternative heating means may be substituted, such as resistive heating, chemical burning, laser, etc. The heating means may be user replaceable to facilitate maintenance.

Optionally, an HCF may be rotated while heated by a fiber rotation mechanism to avoid the fiber bending due to gravity, or the device can be orientated such that the fiber is vertical. A collection unit 29 is optional and may capture waste, such as parts of HCF removed by the device. Collecting waste fiber, sometimes termed fiber scraps or shards, prevents the fiber scraps from contaminating the remaining HCF thereby improving the yield of successfully divided and hermetically sealed HCFs. Further, fiber sharps are harmful in the environment and can act like needles causing damage or harm to both animals and people.

[0017] Controller 26 includes electronic components and may operate to control aspects of the device such as heating, clamping and applying a biasing force or tension within a fiber. Second clamping means 23 may provide a biasing force to the HCF 21. The biasing force applied to the second portion 212 may be generated by a spring or by a small motor that creates tension in the second portion 212 by moving the second clamping means away from the first clamping means 22 and therefore away from the heating zone 24. Similarly, movement of the first clamping means may be generated by either a spring or electromechanically controlled by controller 26.

[0018] In some examples, coating or buffer is manually removed prior to use of a device described herein. In some examples, a camera may be used to ensure proper fiber alignment within a device and effective sealing has occurred. In some examples, the device may further comprise a recoating mechanism to add a protective coating to exposed fiber material post sealing and/or dividing.

[0019] In some examples, a device described herein may further comprise a marking tool to mark an HCF that has undergone a sealing and/or dividing process. The marking tool may apply paint or ink to one or more HCFs. 6

MS Docket No. 413543-LU-NP

[0020] Timing and biasing forces are discussed in relation to FIG. 6. LU506198

[0021] While one HCF 21 is illustrated in FIG. 2, multiple HCFs may be placed in the device and all divided and hermetically sealed simultaneously.

[0022] FIG. 3 illustrates a schematic diagram of a second exemplary device 30 for hermetically sealing one or more HCFs. A controller is not illustrated in FIG. 3 but may be included for controlling components, such as heating means 351, 352 and, optionally, clamping means 32 or movement A3 of clamping means.

[0023] The device 30 can receive one or more HCFs 31, optionally a bundle of

HCFs, for example a cable. While multiple HCFs 31 are illustrated in the FIG. 3, a single

HCF may be placed in the device 30 individually divided and hermetically sealed. When

HCFs are inserted into the device 30, they pass through a heating zone 34. The heating zone 34 can be heated using heating means that, in the illustrated example are electrodes 351, 352 that can arc if a potential difference is applied across them. The power supplied to the electrodes can be varied to change heating characteristics of the heating zone. Heat applied to the heating zone 34 can be sufficient to melt one or more HCF in proximity to the zone 34 thereby aiding in the dividing and hermetic sealing of the HCF.

[0024] After insertion of HCF 31 into device 30, clamping means 32 can engage to hold a first portion of the inserted HCF in place while a second portion of the inserted

HCF hangs down under gravity pulling the second portion away from the first portion creating tension in the HCF within the heating zone 34. The controlled application of heat to the heating zone 34 can destroy internal structures within HCF leading to collapse of the internal HCF structures and a reduction in the diameter of the HCF. The gravitational force acting on the second portion of HCF may divide the HCF at a point within the heating zone 34. Optionally, the clamping means 32 may be used to move in direction A3 the first portion of the HCF towards the heating zone before, during or after dividing of the second portion has occurred. This heating of additional parts of the first portion can collapse additional areas of internal structures leading to an improved and more robust hermetic seal. Not illustrated but the device 31 may include a second clamping means that may be movable so as to not rely on a gravitational biasing force to divide the HCF.

[0025] A collection unit 39 is optional and may capture waste, such as portions of

HCF 31 divided by the device 30. The collection unit 39 may be internal within the device or external, as illustrated in FIG. 3.

[0026] In a non-illustrated embodiment, clamping means 32 is not present and a user of device 30 can hold HCF 31 in place while the HCF 31 is divided at heating zone 7

MS Docket No. 413543-LU-NP

34. Device 30 may further comprise a funnel to facilitate a user inserting HCF 31 on the LU506198 device 30.

[0027] FIG. 4A illustrates a section of HCF 41 with an unsealed end (at the right side of the figure). There are many configurations of HCF not limited to those in FIGs. 1B and 1C. In FIG. 4A, the type of HCF illustrated in FIG. 1B is used. The figure illustrates a small section of a long length of HCF where one end is open allowing contamination of the hollow core. The open end of the HCF may be placed in or inserted through the device illustrated in FIG. 2 and subject to heat and dividing. The point about which heat is centered is represented by a dashed line in FIG. 4A.

[0028] FIG. 4B illustrates the section of HCF of FIG. 4A but with a sealed end.

End 420 is hermetically sealed and any contaminants introduced further down the fiber are removed by the removal of the contaminated fiber length.

[0029] FIG. S illustrates a third exemplary device 50 for hermetically sealing a

HCF 51. The portable device 50 has an opening 52 in a top surface for receiving the HCF 51. In some examples, the device comprises a battery chargeable by an external power source via a plug socket 55. A display 53 shows operational parameters that may be editable by button controls. The controls comprise a power button 541, a start/stop button 542, and up and down buttons 543, 544. A waste collection unit 56 collects waste material and comprises a handle 560 to facilitate emptying and safe disposal of sharp fiber lengths.

Not illustrated in FIG. 5 is a fume venting mechanism to force air away from the heat zone. The mechanism may be a fan located within device 50. The forced air may comprise fumes or smoke resulting from heating therefore the movement of air from the heat zone will keep the heat zone area, including the electrodes, free from contaminants. The fume venting mechanism may be combined with other examples described and illustrated herein. Not illustrated in FIG. 5 or the schematic illustrations of FIGs. 2 and 3 is an optional detection mechanism, which is a sensor arranged to automatically detect a fiber inserted into the device, whereby the detected fiber insertion automatically initiates a dividing and/or sealing process described and illustrated herein.

[0030] FIG. 6 illustrates a flow diagram of a method for hermetically sealing a

HCF.

[0031] Block S1 consists of inserting an HCF into a device, the HCF comprising a first portion and a second portion. The second portion is to be divided from the first and the first portion hermetically sealed to protect it from external contaminants. 8

MS Docket No. 413543-LU-NP

[0032] Block S2 consists of clamping the inserted first portion of the HCF to the LU506198 device. The clamping enables a precise dividing and also facilitates collapsing of structures within the HCF by the application of tension along the HCF.

[0033] Block S3 consists of biasing the second portion of the HCF away from the clamped first portion. The biasing creates tension along the HCF.

[0034] Block S4 consists of applying heat at a position along the inserted HCF, the position being between the first portion and the second portion of the HCF.

[0035] Block S5 consists of collapsing a structure of the inserted HCF to hermetically seal the hollow core of the HCF from outside the HCF. Once the hollow core structures are collapsed, there is no opening for external contaminants to enter the hollow core.

[0036] Block S6 consists of dividing, at the heating position, the second portion of the HCF from the hermetically sealed first portion of the HCF. The dividing may be purely due to the applied heating or a combination of heating and a drawing of the second portion from the first portion.

[0037] It is described that gravity, a spring or an electro-mechanical component can be used to induce tension along the HCF by drawing the second portion away from the first portion. Should a spring be used, there is no lower limit to provide an effective dividing, however a spring providing a force of 2 Newtons is sufficient to increase the speed of dividing while still enabling a hermetic seal for the divided section. Should the glass of an HCF be unusually thick or there are multiple HCFs being divided then additional heat, additional duration of heat and/or an increased tension may be applied.

[0038] Should an electro-mechanical component, such as a motor, be used then a motor can be arranged to provide tension by a movement of, for example, 10 to 50 micrometres to create sufficient tension to increase dividing speed.

[0039] An example schedule for dividing and hermetically sealing using a device according to that of FIG. 2 is provided, however the constituent actions will vary based on the structure and number of HCFs being divided and hermetically sealed. From time 0 to around 4 seconds, heat using an arc power corresponding to a current of approximately 19 mA. From approximately time 1 to 3 seconds, apply a motor to move second clamp 23 in direction of arrow A2 at a speed lum/ms to divide into two portions. From approximately time 3 to 4 seconds, apply a motor to move first clamp 22 in direction of arrow Al at a speed of approximately 0.08 um/ms to enter additional HCF into the heat zone 24 and create a rounded end. Heating temperature, heating time, applied tension and HCF 9

MS Docket No. 413543-LU-NP diameter are related when hermetically sealing and dividing HCF, e.g., a greater LU506198 temperature may require a smaller heating duration; a greater tension may require a lower temperature and/or heating time; and thinner HCF may require a lower tension, heating temperature and/or heating time. A schedule/device for dividing and hermetically sealing must generally include subjecting an inserted HCF, in the heat zone, to a power sufficient to melt the HCF material, so for a glass HCF the power supplied to the heating zone must be sufficient to melt glass, i.e., approximately at or greater than 1,600 degrees Celsius.

[0040] FIG. 7 illustrates a schematic diagram of an exemplary computing-based device for use in controlling example devices.

[0041] Alternatively, or in addition, the functionality described herein is performed, at least in part, by one or more hardware logic components. For example, and without limitation, illustrative types of hardware logic components that are optionally used include Field-programmable Gate Arrays (FPGAs), Application-specific Integrated

Circuits (ASICs), Application-specific Standard Products (ASSPs), System-on-a-chip systems (SOCs), Complex Programmable Logic Devices (CPLDs), Graphics Processing

Units (GPUs) and/or Microcontrollers.

[0042] FIG. 7 illustrates various components of an exemplary computing-based controller device 1000 which are implemented as any form of a computing and/or electronic device, for controlling example devices illustrated in FIGs 2, 3 and 5.

[0043] Computing-based controller device 1000 comprises one or more processors 1001 which are microprocessors, controllers, or any other suitable type of processors for processing computer executable instructions to control the operation of the device in order to provide heating and/or biasing controls. In some examples, for example where a system on a chip architecture is used, the processors 1001 include one or more fixed function blocks (also referred to as accelerators) which implement a part of the method of FIG. 6 in hardware (rather than software or firmware). Platform software comprising an operating system 1011 or any other suitable platform software is provided at the computing-based device to enable application software 1012 to be executed within the respective device at a controller.

[0044] The computer executable instructions are provided using any computer- readable media that is accessible by computing based device 1000. Computer-readable media includes, for example, computer storage media such as memory 1010 and communications media. Computer storage media, such as memory 1010, includes volatile and non-volatile, removable and non-removable media implemented in any method or

MS Docket No. 413543-LU-NP technology for storage of information such as computer readable instructions, data LU506198 structures, program modules or the like. Computer storage media includes, but is not limited to, random access memory (RAM), read only memory (ROM), erasable programmable read only memory (EPROM), electronic erasable programmable read only memory (EEPROM), flash memory or other memory technology, compact disc read only memory (CD-ROM), digital versatile disks (DVD) or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other non-transmission medium that is used to store information for access by a computing device. In contrast, communication media embody computer readable instructions, data structures, program modules, or the like in a modulated data signal, such as a carrier wave, or other transport mechanism. As defined herein, computer storage media does not include communication media. Therefore, a computer storage medium should not be interpreted to be a propagating signal per se. Although the computer storage media (memory 1010) is shown within the computing-based controller device 1000 it will be appreciated that the storage is, in some examples, distributed or located remotely and accessed via a network or other communication link (e.g., using communication interface 1002).

[0045] The computing-based device 1000 also comprises an input/output controller 1003 arranged to output display information to a display device 1021 which may be separate from or integral to the computing-based device 1000. The display information may provide a graphical user interface. The input/output controller 1003 is also arranged to receive and process input from one or more devices, such as a user input device 1022 (e.g., buttons, a mouse, keyboard, camera, microphone, or other sensor). In some examples the user input device 1000 detects voice input, user gestures or other user actions and provides a natural user interface (NUI). This user input may be used to interact with the device 1000. In an example the display device 1021 also acts as the user input device 1022 if it is a touch sensitive display device. The input/output controller 1003 outputs data to devices other than the display device in some examples, e.g., a locally connected printing device (not shown in FIG. 7).

[0046] Alternatively or in addition to the other examples described herein, examples include any combination of the following:

[0047] Clause A. A device for hermetically sealing a hollow core optical fiber (HCF), the device comprising: a channel sized to receive an HCF into the device; a 11

MS Docket No. 413543-LU-NP clamping means configured to clamp a first portion of the HCF received within the LU506198 device; a heating means configured to heat the HCF received within the device; and a biasing means configured to bias a second portion of the HCF received within the device away from the first portion of the HCF received within the device.

[0048] Clause B. The device of clause A, wherein the heating means is an electrical arc.

[0049] Clause C. The device of any preceding clause, further comprising a collection unit configured to collect the second portion of the HCF after dividing from the clamped first portion of the HCF.

[0050] Clause D. The device of any preceding clause, wherein the clamping means configured to clamp the first portion is movable towards the heating means.

[0051] Clause E. The device of any preceding clause, further comprising a battery, wherein the device is portable and the battery is coupled to the heating means.

[0052] Clause F. The device of any preceding clause, further comprising an opening in a top surface of the device; wherein the channel extends downwards from the opening in the top surface of the device, and wherein the biasing means is a gravitational force acting on the second portion of the HCF extending through the channel.

[0053] Clause G. The device of any preceding clause, wherein the clamping means is a first clamping means; and wherein the biasing means comprises a second clamping means configured to clamp the second portion of the HCF.

[0054] Clause H. The device of any preceding clause, wherein the biasing means is a spring or a motor.

[0055] Clause I. A method of hermetically sealing a HCF, the method comprising: inserting an HCF into a device, the HCF comprising a first portion and a second portion; clamping the inserted first portion of the HCF to the device; biasing the second portion of the HCF away from the clamped first portion; applying heat at a position along the inserted HCF, the position being between the first portion and the second portion of the

HCEF; collapsing a structure of the inserted HCF to hermetically seal the hollow core of the HCF from outside the HCF; and dividing, at the heating position, the second portion of the HCF from the hermetically sealed first portion of the HCF.

[0056] Clause J. The method of clause I, wherein the applied heat is generated by an electrical arc.

[0057] Clause K. The method of clause I or J, further comprising collecting the divided second portion of the divided HCF in a collection unit. 12

MS Docket No. 413543-LU-NP

[0058] Clause L. The method of any of clauses I to K, wherein the HCF is one of a LU506198 plurality of HCFs all inserted into the device as a bundle of HCFs.

[0059] Clause M. The method of clause 9, further comprising moving the first portion of the HCF towards a heating means after application of heat has commenced.

[0060] Clause N. The method of clause 9, wherein the HCF is inserted vertically into the device, and wherein a biasing force is a gravitational force acting longitudinally along the second portion of the HCF.

[0061] Clause O. The method of clause 9, further comprising clamping the inserted second portion of the HCF to the device.

[0062] Clause P. The method of clause O, wherein biasing force 1s created by a spring coupling the clamped second portion of the HCF to the device.

[0063] Clause Q. The method of clause O, wherein biasing force 1s created by a motor-controlled movement of the clamped second portion of the HCF with respect to the device.

[0064] Clause R. À portable device for dividing and hermetically sealing a HCF, the device comprising: a channel sized to receive an HCF into the device, the HCF comprising a first portion and a second portion; a clamping means configured to clamp the first portion of the HCF received within the device; a biasing means configured to bias the second portion of the HCF away from the clamped first portion; a heating means configured to applying heat at a position along the inserted HCF, the position being between the first portion and the second portion of the HCF; and a battery configured to power the heating means; wherein the device 1s operable to collapse a structure of the inserted HCF to hermetically seal the hollow core of the HCF from outside the HCF; and wherein the device is operable to divide, at the heating position, the second portion of the

HCF from the hermetically sealed first portion of the HCF.

[0065] Clause S. The portable device of clause R, wherein the clamping means is operable, during the collapse of the structure, to move the first portion of the HCF towards the heating means.

[0066] Clause T. The portable device of clause R or S, wherein the heating means is configurable by a user of the device.

[0067] Clause U. A non-transient computer readable medium containing program instructions for causing a computer to perform the method of any above clause.

[0068] The examples illustrated and described herein as well as examples not specifically described herein but within the scope of aspects of the disclosure constitute 13

MS Docket No. 413543-LU-NP exemplary means for dividing and/or hermetically sealing an HCF, for example, the LU506198 elements illustrated in FIGs. 2 and 3 to perform the blocks illustrated in FIG. 6.

[0069] The methods described herein are performed, in some examples, by software in machine readable form on a tangible storage medium e.g. in the form of a computer program comprising computer program code means adapted to perform all the operations of one or more of the methods described herein when the program is run on a computer and where the computer program may be embodied on a computer readable medium. The software is suitable for execution on a parallel processor or a serial processor such that the method operations may be carried out in any suitable order, or simultaneously.

[0070] Those skilled in the art will realize that storage devices utilized to store program instructions are optionally distributed across a network. For example, a remote computer is able to store an example of the process described as software. A local or terminal computer is able to access the remote computer and download a part or all of the software to run the program. Alternatively, the local computer may download pieces of the software as needed, or execute some software instructions at the local terminal and some at the remote computer (or computer network). Those skilled in the art will also realize that by utilizing conventional techniques known to those skilled in the art that all, or a portion of the software instructions may be carried out by a dedicated circuit, such as a digital signal processor (DSP), programmable logic array, or the like.

[0071] Any range or device value given herein may be extended or altered without losing the effect sought, as will be apparent to the skilled person.

[0072] Although the subject matter has been described in language specific to structural features and/or methodological acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

[0073] It will be understood that the benefits and advantages described above may relate to one example or may relate to several examples. The examples are not limited to those that solve any or all of the stated problems or those that have any or all of the stated benefits and advantages. It will further be understood that reference to 'an' item refers to one or more of those items.

[0074] The operations of the methods described herein may be carried out in any suitable order, or simultaneously where appropriate. Additionally, individual blocks may 14

MS Docket No. 413543-LU-NP be deleted from any of the methods without departing from the scope of the subject matter LU506198 described herein. Aspects of any of the examples described above may be combined with aspects of any of the other examples described to form further examples without losing the effect sought.

[0075] The term 'comprising' is used herein to mean including the method blocks or elements identified, but that such blocks or elements do not comprise an exclusive list and a method or apparatus may contain additional blocks or elements.

[0076] It will be understood that the above description is given by way of example only and that various modifications may be made by those skilled in the art. The above specification, examples and data provide a complete description of the structure and use of examples. Although various examples have been described above with a certain degree of particularity, or with reference to one or more individual examples, those skilled in the art could make numerous alterations to the disclosed examples without departing from the scope of this specification.

MS Docket No. 413543-LU-NP

Claims (15)

CLAIMS LU506198

1. A device for hermetically sealing a hollow core optical fiber, HCF, (21, 31), the device comprising: a channel sized to receive an HCF into the device; a clamping means (22, 32) configured to clamp a first portion (211) of the HCF received within the device; a heating means (251, 252) configured to heat the HCF received within the device; and a biasing means configured to bias a second portion (212) of the HCF received within the device away from the first portion of the HCF received within the device.

2. The device of claim 1, wherein the heating means is an electrical arc.

3. The device of claim 1, further comprising a collection unit configured to collect the second portion of the HCF after dividing from the clamped first portion of the HCF.

4. The device of claim 1, wherein the clamping means configured to clamp the first portion is movable towards the heating means.

5. The device of claim 1, further comprising a battery, wherein the device is portable and the battery is coupled to the heating means.

6. The device of claim 1, further comprising an opening in a top surface of the device; wherein the channel extends downwards from the opening in the top surface of the device, and wherein the biasing means is a gravitational force acting on the second portion of the HCF extending through the channel.

7. The device of claim 1, wherein the clamping means is a first clamping means; and wherein the biasing means comprises a second clamping means configured to clamp the second portion of the HCF.

8. The device of claim 7, wherein the biasing means is a spring or a motor.

9. A method of hermetically sealing a hollow core optical fiber, HCF, the method comprising: inserting (S1) an HCF into a device, the HCF comprising a first portion and a second portion; clamping (S2) the inserted first portion of the HCF to the device; biasing (S3) the second portion of the HCF away from the clamped first portion; 16 MS Docket No. 413543-LU-NP applying (S4) heat at a position along the inserted HCF, the position being LU506198 between the first portion and the second portion of the HCF; collapsing (S5) a structure of the inserted HCF to hermetically seal the hollow core of the HCF from outside the HCF; and dividing (S6), at the heating position, the second portion of the HCF from the hermetically sealed first portion of the HCF.

10. The method of claim 9, wherein the applied heat is generated by an electrical arc.

11. The method of claim 9, further comprising collecting the divided second portion of the divided HCF in a collection unit.

12. The method of claim 9, wherein the HCF is one of a plurality of HCFs all inserted into the device as a bundle of hollow core optical fibers.

13. The method of claim 9, further comprising moving the first portion of the HCF towards a heating means after application of heat has commenced.

14. The method of claim 9, wherein the HCF is inserted vertically into the device, and wherein a biasing force is a gravitational force acting longitudinally along the second portion of the HCF.

15. The method of claim 9, further comprising clamping the inserted second portion of the HCF to the device. 17 MS Docket No. 413543-LU-NP