Passive optical fiber overload fuse and method of making same

Abstract

The application provides a passive optical fiber overload fuse and a manufacturing method thereof, which comprises: an input single-mode optical fiber for inputting an optical signal; an output single-mode optical fiber for outputting the optical signal; a fused taper fiber section, two ends of which are respectively fused to the cores of the input single-mode optical fiber and the output single-mode optical fiber to form a continuous light path, so that the optical signal input by the input single-mode optical fiber is transmitted to the output single-mode optical fiber to output the optical signal; a sealed protective tube shell for packaging the fused taper fiber section, the fused taper fiber section being arranged in the sealed protective tube shell, and the input single-mode optical fiber and the output single-mode optical fiber penetrating into the fused taper fiber section from two ends of the sealed protective tube shell; and the fused taper fiber section has a taper structure with a thin middle and thick ends, comprising a waist region in the middle and thick taper regions at the two ends, the waist region allowing the optical signal with a power less than or equal to a set threshold to pass through, and the waist region being fused when the power of the input optical signal is greater than the set threshold.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of optical fiber technology, in particular to a passive optical fiber overload fuse and a manufacturing method thereof. BACKGROUND

[0002] In the field of optical fiber communication, high-power laser processing, optical sensing, etc., optical elements (such as laser diodes, optical amplifiers, precision detectors, etc.) are extremely sensitive to input optical power. Instantaneous power overload (caused by factors such as accidental reflection, uncontrolled pump source, lightning-induced current, etc.) can easily cause permanent damage to the optical elements, resulting in huge economic losses.

[0003] Currently, common protection schemes are mainly based on the following two principles:

[0004] Optical switch type: using thermal-optical effect, electro-optical effect or acousto-optical effect, etc. to control the optical switch to switch or close the optical path when overload is detected. This type of scheme has fast response speed, but the structure is complex, the cost is high, and it needs external power supply and control circuit, and the reliability is affected by electronic elements.

[0005] Recoverable type: using the nonlinear optical effect (such as nonlinear scattering, saturated absorption) of certain materials to attenuate the optical signal when the power is too high. When the power returns to normal, the device function also recovers. However, its dynamic range is limited, and it has insufficient protection capability for extreme overload (such as pulse impact), and may introduce nonlinear distortion.

[0006] Therefore, it is necessary to provide a passive optical fiber overload fuse and a manufacturing method thereof to effectively solve the above problems. SUMMARY

[0007] The present application provides a passive optical fiber overload fuse and a manufacturing method thereof, which sets a single-mode optical fiber with a fused taper optical fiber segment to achieve irreversible fused physical rupture due to thermal imbalance at a specific overload power, thereby achieving passive overload protection.

[0008] The present application provides a passive optical fiber overload fuse, which comprises:

[0009] an input single-mode optical fiber for inputting an optical signal;

[0010] an output single-mode optical fiber for outputting an optical signal;

[0011] a fused taper optical fiber segment, both ends of which are fused to the cores of the input single-mode optical fiber and the output single-mode optical fiber to form a continuous optical path, so as to transmit the optical signal input by the input single-mode optical fiber to the output single-mode optical fiber to output the optical signal;

[0012] a sealed protective tube, configured to encapsulate the fused taper fiber segment, the fused taper fiber segment being disposed in the sealed protective tube, the input single-mode optical fiber and the output single-mode optical fiber being connected to two ends of the fused taper fiber segment respectively from two ends of the sealed protective tube into the sealed protective tube;

[0013] wherein the fused taper fiber segment has a taper structure with a thin middle and thick ends, including a waist region in the middle and thick taper regions at the two ends, the waist region allowing the passing of optical signals with power less than or equal to a set threshold, and the waist region being fused off to prevent the passing of optical signals when the power of the input optical signal is greater than the set threshold.

[0014] Preferably, the threshold of the maximum power of the optical signal allowed to pass through the waist region of the fused taper fiber segment is determined by the effective length, the minimum diameter of the waist region, and the absorption coefficient of the material of the waist region at the working wavelength and the heat dissipation constant of the material.

[0015] Preferably, the threshold of the maximum power of the optical signal allowed to pass through the waist region of the fused taper fiber segment is calculated by the following formula:

[0016]

[0017] P: is the threshold of the maximum power of the optical signal allowed to pass through the waist region of the fused taper fiber segment;

[0018] K: is a comprehensive constant related to the thermal conductivity, specific heat capacity, and heat dissipation conditions of the material of the waist region, which is obtained by experiment calibration;

[0019] : is the absorption coefficient of the material of the waist region at the working wavelength ;

[0020] d: is the minimum diameter of the waist region (unit: μm);

[0021] L: is the effective length of the waist region (unit: mm).

[0022] Preferably, the minimum diameter of the waist region of the fused taper fiber segment ranges from 1 μm to 5 μm.

[0023] Preferably, the fiber material of the fused taper fiber segment is doped and modified, and the doping elements of the doping and modification include iron (Fe) ions, copper (Cu) ions, or hydroxyl (OH-), so as to increase the absorption coefficient at the set wavelength.

[0024] Preferably, a substrate is further included, which is arranged in the sealed protective tube shell, and the input single-mode optical fiber is fixed by UV glue to one end of the substrate penetrating into the sealed protective tube shell, and the output single-mode optical fiber is fixed by UV glue to the other end of the substrate penetrating into the sealed protective tube shell.

[0025] Preferably, the sealed protective tube shell is made of glass, ceramic or metal.

[0026] Preferably, the two ends of the sealed protective tube shell are sealed by sealing materials, which are ultraviolet curing glue, epoxy resin or metal solder.

[0027] Based on the same concept, the application further provides a manufacturing method of the passive optical fiber overload fuse, which comprises the following steps:

[0028] The single-mode optical fiber to be processed is selected according to the threshold of the maximum power of the optical signal allowed by the passive optical fiber overload fuse, and the length L and the minimum diameter d of the waist region of the fused taper fiber segment are set;

[0029] The middle part of the single-mode optical fiber to be processed is stripped and cleaned;

[0030] In the tapering device, the middle part of the single-mode optical fiber to be processed is heated and stretched to form a fused taper fiber segment with a predetermined minimum diameter d and a length L, and the parts of the single-mode optical fiber to be processed connected to the two ends of the fused taper fiber segment are used as the input single-mode optical fiber and the output single-mode optical fiber;

[0031] The substrate is provided, and the input single-mode optical fiber and the output single-mode optical fiber are fixed to the two ends of the substrate by UV glue, so that the fused taper fiber segment is located in the middle part of the substrate;

[0032] The sealed protective tube shell is provided, the substrate is placed in the sealed protective tube shell, and the input single-mode optical fiber and the output single-mode optical fiber penetrate out of the two ends of the sealed protective tube shell, respectively;

[0033] The sealing materials are provided to seal the two ends of the sealed protective tube shell.

[0034] Based on the same concept, the application further provides an optical device, which comprises a laser source, an optical functional device and optical fibers connecting them, and the passive optical fiber overload fuse is connected in series in the optical path between the laser source and the optical functional device.

[0035] Compared with the prior art, the technical scheme of the embodiment of the application has the following beneficial effects:

[0036] The passive optical fiber overload fuse and the manufacturing method thereof provided by the embodiment of the application, which is characterized in that a fused taper fiber section is arranged in a single-mode optical fiber, and the fused taper fiber section is fused at the waist region when the power of the input optical signal is greater than a set threshold, thereby preventing the optical signal from passing through to realize overload protection, and the passive operation does not require an external power supply, a sensor or a control circuit, and the reliability is extremely high; the response speed is extremely fast, and the heat accumulation and the fusing process are completed within microseconds to milliseconds, so that the destructive optical pulse can be effectively responded to; the structure is simple, and the cost is low; the optical fiber tapering process is mature, and the batch production is easy; the protection is reliable, and once the action is taken, the physical disconnection is realized, and there is no possibility of recovery, so that the subsequent risks are completely eliminated; and the protection can be customized flexibly, and the fusing threshold under different wavelengths and powers can be accurately designed by changing the diameter, the length and the material of the waist region. BRIEF DESCRIPTION OF DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are some embodiments of the application, rather than all the embodiments. Those skilled in the art can obtain other drawings according to these drawings without any creative labor.

[0038] Figure 1 The passive optical fiber overload fuse structure schematic diagram provided by an embodiment of the application;

[0039] Figure 2 The fused taper fiber section structure schematic diagram provided by an embodiment of the application;

[0040] Figure 3 The passive optical fiber overload fuse manufacturing method flow chart provided by an embodiment of the application.

[0041] In the drawings:

[0042] 1-sealing protection tube shell; 2-substrate; 3-input single-mode optical fiber; 4-UV glue; 5-fused taper fiber section; 51-coarse taper region; 52-waist region; 6-sealing material; 7-output single-mode optical fiber. DETAILED DESCRIPTION

[0043] In order to make the purpose, the technical solutions and the advantages of the embodiments of the application more clear, the technical solutions in the embodiments of the application will be described clearly and completely in the following with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are some embodiments of the application, rather than all the embodiments. Based on the embodiments in the application, all the other embodiments obtained by those skilled in the art without any creative labor are within the protection scope of the application.

[0044] The technical solutions of the present application are described in detail below with specific examples. The following specific examples can be combined with each other, and the same or similar concepts or processes can not be described in some examples.

[0045] Based on the problems in the prior art, the embodiment of the present application provides a passive optical fiber overload fuse and a manufacturing method thereof. A single-mode optical fiber with a fused taper fiber section is arranged to realize irreversible fusion physical fracture due to thermal imbalance under a specific overload power, thereby realizing passive overload protection.

[0046] Figure 1 A passive optical fiber overload fuse structure diagram is provided for an embodiment of the present application. Figure 2 A fused taper fiber section structure diagram is provided for an embodiment of the present application. Figure 3 A passive optical fiber overload fuse manufacturing method flow chart is provided for an embodiment of the present application.

[0047] Now referring to Figure 1 and Figure 2 the embodiment of the present application provides a passive optical fiber overload fuse, comprising:

[0048] an input single-mode optical fiber 3 for inputting an optical signal;

[0049] an output single-mode optical fiber 7 for outputting an optical signal;

[0050] a fused taper fiber section 5, both ends of which are fused to the cores of the input single-mode optical fiber 3 and the output single-mode optical fiber 7 to form a continuous optical path, so as to transmit the optical signal input by the input single-mode optical fiber 3 to the output single-mode optical fiber 7 to output the optical signal;

[0051] a sealed protective tube shell 1 for packaging the fused taper fiber section 5, the fused taper fiber section 5 being arranged in the sealed protective tube shell 1, and the input single-mode optical fiber 3 and the output single-mode optical fiber 7 being connected to both ends of the fused taper fiber section 5 by penetrating into the sealed protective tube shell 1 from both ends of the sealed protective tube shell 1;

[0052] wherein the fused taper fiber section 5 has a tapered structure with a thin middle and thick ends, including a waist region 52 in the middle and thick taper regions 51 at both ends, the waist region 52 allowing the optical signal with a power less than or equal to a set threshold to pass through, and the waist region 52 being fused to block the optical signal from passing through when the power of the input optical signal is greater than the set threshold.

[0053] Specifically, according to electromagnetic field theory, when the optical signal is transmitted in the taper waist region 52, part of the light will be transmitted outside the fiber cladding in the form of evanescent field. At the minimum diameter of the taper waist region 52, the optical field is greatly compressed, resulting in a significantly higher optical power density in this region than in other regions. The fiber material (quartz) has a very weak absorption of light (especially at a specific wavelength, which can be enhanced by doping), and the absorbed energy will be converted into heat. At normal use power, the generated heat can be dissipated in time through heat conduction and convection, and the temperature remains stable. Once the input power exceeds the set threshold, the heat absorbed by the taper waist region 52 will exceed its heat dissipation capacity, causing the temperature in this region to rise sharply. When the temperature reaches the softening point of quartz glass (about 1600°C), the region will quickly melt, shrink and eventually burn out, forming a physical open circuit, and the optical path is permanently cut off.

[0054] In some embodiments, the threshold of the maximum power of the optical signal allowed to pass through the taper waist region 52 of the fused biconical taper fiber segment 5 is determined by the effective length, the minimum diameter of the taper waist region 52, and the absorption coefficient of the material of the taper waist region 52 at the working wavelength, as well as the heat dissipation constant of the material.

[0055] In some embodiments, the threshold of the maximum power of the optical signal allowed to pass through the taper waist region 52 of the fused biconical taper fiber segment 5 is calculated by the following formula:

[0056]

[0057] P: is the threshold of the maximum power of the optical signal allowed to pass through the taper waist region of the fused biconical taper fiber segment;

[0058] K: is a comprehensive constant related to the thermal conductivity, specific heat capacity, and heat dissipation conditions of the material of the taper waist region, which is calibrated by experiment;

[0059] : is the absorption coefficient of the material of the taper waist region at the working wavelength

[0060] d: is the minimum diameter of the taper waist region (unit: pm);

[0061] L: is the effective length of the taper waist region (unit: mm).

[0062] In some embodiments, the minimum diameter of the taper waist region 52 of the fused biconical taper fiber segment 5 ranges from 1 pm to 5 pm.

[0063] In some embodiments, the fiber material of the fused biconical taper fiber segment 5 is modified by doping, and the doping elements of the doping modification include iron (Fe) ions, copper (Cu) ions, or hydroxyl (OH-), to increase the absorption coefficient at the set wavelength.

[0064] ​In some embodiments, the substrate 2 is arranged in the sealed protective tube 1, the input single-mode optical fiber 3 is fixed in the sealed protective tube 1 by the UV glue 4 and is fixed to one end of the substrate 2, and the output single-mode optical fiber 7 is fixed in the sealed protective tube 1 by the UV glue 4 and is fixed to the other end of the substrate 2.

[0065] Specifically, the input single-mode optical fiber 3 and the output single-mode optical fiber 7 are fixed to the substrate 2 by the UV glue 4, the influence of the input single-mode optical fiber 3 and the output single-mode optical fiber 7 on the fused taper fiber section 5 is reduced, and the input single-mode optical fiber 3 or the output single-mode optical fiber 7 does not exert a pulling force on the fused taper fiber section 5 in the process of installation or use, so that the waist region 52 of the fused taper fiber section 5 is not broken and damage is avoided.

[0066] In some embodiments, the sealed protective tube 1 is made of glass, ceramic or metal, and the internal cavity is a closed environment, which is air, inert gas or vacuum.

[0067] In some embodiments, the two ends of the sealed protective tube 1 are sealed and closed by the sealing material 6, and the sealing material 6 is UV curing glue, epoxy resin or metal solder.

[0068] Specifically, when the sealed protective tube 1 is made of glass, the sealing material 6 is UV curing glue; when the sealed protective tube 1 is made of ceramic, the sealing material 6 is epoxy resin; and when the sealed protective tube 1 is made of metal, the sealing material 6 is metal solder.

[0069] Please refer to Figure 3 The application further provides a manufacturing method of the passive optical fiber overload fuse, which comprises the following steps:

[0070] S1: selecting a single-mode optical fiber to be processed according to a threshold value of the maximum power of the optical signal allowed to pass through the passive optical fiber overload fuse, and setting the length L and the minimum diameter d of the waist region 52 of the fused taper fiber section 5;

[0071] S2: performing stripping and cleaning treatment on the middle part of the single-mode optical fiber to be processed;

[0072] S3: heating and stretching the region after the middle part treatment of the single-mode optical fiber to be processed in a tapering device to form the fused taper fiber section 5 with the predetermined minimum diameter d and the length L of the waist region 52, and connecting the parts of the single-mode optical fiber to be processed at the two ends of the fused taper fiber section 5 as the input single-mode optical fiber 3 and the output single-mode optical fiber 7;

[0073] S4: providing the substrate 2 to fix the input single-mode optical fiber 3 and the output single-mode optical fiber 7 to the two ends of the substrate 2 by the UV glue 4, so that the fused taper fiber section 5 is located in the middle part of the substrate 2;

[0074] S5: providing a sealed protective tube 1, placing the substrate 2 in the sealed protective tube 1, and making the input single-mode optical fiber 3 and the output single-mode optical fiber 7 pass through two ends of the sealed protective tube 1 respectively;

[0075] S6: providing the sealing material 6 to seal and close two ends of the sealed protective tube 1.

[0076] Specifically, the single-mode optical fiber to be processed can also be selected according to the wavelength of the optical signal to be transmitted, that is, the single-mode optical fiber to be processed is doped and modified according to the wavelength and power of the optical signal to be transmitted and the characteristic doping element.

[0077] The application further provides an optical device comprising a laser source, an optical functional device, and an optical fiber connecting them, and the passive optical fiber overload fuse is connected in series on an optical path between the laser source and the optical functional device.

[0078] In summary, the passive optical fiber overload fuse and the manufacturing method thereof provided by the embodiments of the application set the fused taper optical fiber section 5 on the single-mode optical fiber, and the taper waist region 52 of the fused taper optical fiber section 5 is fused when the power of the input optical signal is greater than the set threshold, so as to prevent the optical signal from passing through and achieve overload protection; the passive optical fiber overload fuse works completely passively, without an external power supply, a sensor, or a control circuit, and has extremely high reliability; the response speed is extremely fast, and the heat accumulation and the fusing process are completed within microseconds to milliseconds, so that the passive optical fiber overload fuse can effectively cope with destructive optical pulses; the structure is simple, and the cost is low; the passive optical fiber overload fuse is based on a mature optical fiber tapering process and is easy to mass-produce; the protection is reliable, and once the passive optical fiber overload fuse acts, it is physically disconnected and has no possibility of recovery, so that subsequent risks are completely eliminated; the passive optical fiber overload fuse is flexible to customize, and the fusing threshold under different wavelengths and powers can be accurately designed by changing the diameter, the length, and the material of the taper waist region 52.

[0079] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the application, but not to limit them; although the application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the application.

Claims

1. A passive optical-fiber overload fuse, characterized by, The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. P: a threshold for a maximum power of an optical signal allowed to pass through the taper waist region of the fused taper optical fiber segment; The application relates to a passive optical fiber overload fuse. : absorption coefficient of the material of the conical waist region at the working wavelength : absorption coefficient of the material of the conical waist region at the working wavelength The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse.

2. The passive optical-fiber overload fuse of claim 1, wherein, The application relates to a passive optical fiber overload fuse.

3. The passive optical-fiber overload fuse of claim 1, wherein, The application relates to a passive optical fiber overload fuse.

4. The passive optical-fiber overload fuse of claim 1, wherein, The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application relates to a passive optical fiber overload fuse. The application 5. The passive optical-fiber overload fuse of claim 1, wherein, Further comprising a substrate, which is arranged in the sealed protective tube, and the input single-mode optical fiber is fixed by UV glue to one end of the substrate, and the output single-mode optical fiber is fixed by UV glue to the other end of the substrate.

6. The passive optical-fiber overload fuse of claim 1, wherein, The sealed protective tube is made of glass, ceramic or metal.

7. The passive optical-fiber overload fuse of claim 1, wherein, The two ends of the sealed protective tube are sealed by sealing material, which is UV curing glue, epoxy resin or metal solder.

8. An optical device comprising a laser source, an optically functional device, and an optical fiber connecting them, characterized by, A passive optical fiber overload fuse as claimed in any one of claims 1 to 7 is connected in series in the optical path between the laser source and the optical functional device.

Images