JP4959647B2 - Optical fiber end face processing apparatus and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical fiber end face treatment device capable of joining an optical fiber and a ferrule, forming a polished surface and sealing a hole concurrently and with a high degree of precision, for an optical fiber with a hole. <P>SOLUTION: In the optical fiber end face treatment device for performing end face treatment of an optical fiber 3 by a melting method using a laser light source or a heat source 1, a temperature distribution having a plurality of peaks in a processing cross-section of the optical fiber 3 is formed using a lens, a shielding plate or a reflection plate 2. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to an optical fiber end surface processing apparatus and method for processing an end surface of an optical fiber by melting using a laser light source or a heat source.

An optical fiber is a basic component that supports an optical fiber transmission system, and is connected to various optical components via a connector. However, complicated end face processing is essential for connectorization in order to suppress connection loss and reflection loss. In particular, the process of placing the fiber in a ferrule and fixing it with an adhesive or the PC (Physical Contact) polishing process after assembling the connector has a large manufacturing load (uses a polishing machine and requires frequent replacement of the polishing paper) ).

  In addition, when using a fiber with holes as an optical fiber (holi fiber, hole assisted fiber, photonic bandgap fiber), sealing the holes to prevent dust and moisture from entering the holes. A process is necessary, and the process is further complicated.

  In addition, in the MT connector (Mechanically Transferable Splicing Connector), a refractive index matching agent is used to suppress reflection loss, but the refractive index matching agent has a relatively high temperature dependence, and depending on the temperature, there is a large reflection loss. To increase.

  Under such circumstances, various studies have been made with the aim of simplifying the connectorization process.

Regarding the fixing of the optical fiber to the ferrule, it is conceivable to join the optical fiber and the ferrule by heating the end face (laser, arc discharge, etc.) after insertion into the ferrule (hereinafter referred to as analogy technique).
As for the polishing of the end face, it has been reported that only the vicinity of the core portion is irradiated with a carbon dioxide laser and melted (see, for example, Patent Document 1).
As for hole sealing, there are a method of melting and fusing the end face by arc discharge, a method of injecting an adhesive into the hole and sealing, a method of fusing and fusing the end face by laser irradiation, etc. It has been proposed (see, for example, Patent Document 2).

  In the above analogy technique, Patent Documents 1 and 2, since no refractive index matching agent is used, the temperature dependence is small and low reflection can be expected for a wide range of temperature changes. Therefore, it can be used not only indoors where the temperature is relatively stable, but also outdoors.

  However, using the analogy technique described above and Patent Documents 1 and 2, the optical fiber end face treatment (joining of optical fiber and ferrule, sealing of holes, formation of PC polished surface (no need of PC polishing treatment)) When performing in a series of processing, there are the following problems.

The analogy technique has a problem in that it requires a PC polishing process.
In addition, as a problem of Patent Document 1, only a solid optical fiber is a target, the correspondence to a hole optical fiber is unclear, and only the central part of the core is irradiated with laser. Is not possible (subject to enhanced optical fiber).
Further, as a problem of Patent Document 2, it is impossible to form a PC polished surface and join an optical fiber and a ferrule only by sealing holes (for holes optical fiber).

  Further, when examining whether or not the above analogy technique and Patent Document 1 can be processed in three steps, the analogy technique heats the entire tip of the optical fiber, so that it melts widely in the longitudinal direction of the optical fiber. However, since the waveguide structure collapses near the tip of the optical fiber as it is, low connection loss and low reflection cannot be obtained unless the portion that has been destroyed by polishing or the like is scraped off. Therefore, even if the process of Patent Document 1 is performed thereafter to form a PC polished surface, low loss connection is difficult. In addition, since Patent Document 1 is a process for solid fibers, it is difficult to form a PC polished surface, and the waveguide structure collapses further due to excessive melting, and conversely loss and reflection degradation occur. There are concerns about such points. Since Patent Document 2 (in the case of laser irradiation and arc discharge) is included in the analogy technique, even if this process is added, the problem cannot be solved.

JP 7-318756 A JP 2002-323625 A International Telecommunication Union Study Group 15, Telecommunication Standardization Sector TD310 Revl (PLEN / 15), Temporary Document “Draft Recomendation”.

The present invention has been made in view of the above circumstances. At the end face of an optical fiber, at least hole sealing and polishing surface formation can be easily performed among hole sealing, polishing surface formation, and joining of an optical fiber and a ferrule. An object of the present invention is to provide an optical fiber end face processing apparatus and method that can form a temperature distribution with high accuracy so as to be realizable.

The first optical fiber end surface processing apparatus and method in terms of the present invention, using a laser beam source, melting the end face of the optical fiber holes are arranged between the core and the outer edge in order to achieve the above object In the optical fiber end surface processing apparatus and method for performing the end surface processing of the optical fiber, first, the laser light output from the laser light source is converted into a parallel beam using a Fresnel lens. Then, using a diffractive lens, based on the laser light converted into a parallel beam by the Fresnel lens, an annular first optical power region having a first intensity and a first diameter, and An annular second optical power region having a second intensity lower than the first intensity and having a second diameter larger than the first diameter is generated, and the first optical power area is A high temperature first annular temperature portion for irradiating the hole at the end face of the optical fiber to seal the hole at the position is formed, and the second optical power region is Forming a second annular temperature part having a temperature lower than that of the first annular temperature part for irradiating the outer edge part of the end face of the optical fiber and polishing the outer edge part on the outer edge part; It is.
According to a first aspect of the present invention, there is provided a third intensity lower than the second intensity based on a laser beam converted into a parallel beam by the Fresnel lens using the diffraction lens, and An annular third optical power region having a third diameter different from the first and second diameters is further generated, and the third optical power region is formed at a portion other than the holes on the end face of the optical fiber. A third annular temperature part having a temperature lower than that of the second annular temperature part for irradiating and smoothing the end face of the optical fiber at the part is further formed.
A first aspect of the present invention is an annular first lens having a first intensity and a first diameter based on laser light converted into a parallel beam by the Fresnel lens using a diffraction lens. A first optical power region, an annular second optical power region having a first intensity and a second diameter larger than the first diameter, and lower than the first intensity and the first and first Each of the annular third optical power regions having a third diameter different from the diameter of 2, and irradiating the first optical power region to the position where the holes of the end face of the optical fiber are disposed Forming a high-temperature first annular temperature portion for sealing the hole at a position, and irradiating the interface between the optical fiber and the ferrule with the second optical power region. Forming a high-temperature second annular temperature part for joining A third annular temperature part is formed at a temperature lower than the first and second annular temperature parts for irradiating a part other than the holes with the third optical power region to smooth the part. It is also characterized.

In order to achieve the above object, an optical fiber end surface processing apparatus and method according to the second aspect of the present invention uses a heat source to melt an end surface of an optical fiber in which holes are arranged between a core and an outer edge. In the optical fiber end surface processing method for performing the end surface processing of the optical fiber by using a radiant heat reflecting plate having a plurality of annular holes having different diameters, the first strength is obtained based on the heat generated from the heat source. And an annular first heat power region having a first diameter, an annular first heat power region having a second intensity lower than the first intensity and a second diameter larger than the first diameter. Each of the second thermal power regions is generated, and the first thermal power region is irradiated to the position where the holes on the end face of the optical fiber are disposed to seal the holes at the positions. 1 and the second heat power. Forming a second annular temperature portion having a temperature lower than that of the first annular temperature portion for irradiating the outer edge portion of the optical fiber end surface with the region to polish the outer edge portion. It is what.
  According to a second aspect of the present invention, there is provided a third intensity lower than the second intensity based on the heat generated from the heat source using the radiant heat reflector, and the first and first An annular third thermal power region having a third diameter different from the diameter of 2 is generated, and the third thermal power region is irradiated to a portion other than the holes on the end face of the optical fiber, A third annular temperature portion having a temperature lower than that of the second annular temperature portion for smoothing the end face of the optical fiber is formed in the region.

According to the optical fiber end face processing apparatus and method of the present invention , at least the pore sealing and the polishing surface formation can be easily and simultaneously performed on the end face of the optical fiber . As a result, the process is greatly simplified as compared with the prior art, and an improvement in productivity can be expected as the manufacturing time is shortened. In addition , at least the hole sealing and the polishing surface formation are integrally performed, so that the yield is improved, which greatly contributes to the economy of the optical fiber end face processing.

  Further, since a PC polishing step is not required, a polishing machine or polishing paper (replacement frequently) is not required. Further, since the end face can be processed by only one melting, an improvement to the mechanical thermal history of the glass is expected, and an improvement is also expected in terms of reliability.

  In addition, since no refractive index matching agent is used, the temperature dependence is small and low reflection can be expected for a wide range of temperature changes. Therefore, it can be used not only indoors where the temperature is relatively stable, but also outdoors. In addition, since the optical fiber end face processing apparatus uses common parts for all processes, it is possible to provide a low-cost apparatus. In addition, the highly accurate process contributes to improved connector characteristics.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[Embodiment 1]
FIG. 1 is an explanatory diagram illustrating a configuration of an optical fiber end surface processing apparatus according to an embodiment of the present invention. In FIG. 1, 1 is a light source or heat source, 2 is a lens or shielding plate or reflecting plate, 3 is an optical fiber, 4 is a reflection side monitor (reflection side detector), and 5 is a monitor of transmitted light after passing through the optical fiber. It is a transmission side monitor (transmitted light power detector). Examples of the reflection-side monitor 4 include a detector that monitors optical power, a thermo viewer that monitors temperature distribution, and the like.

  As shown in FIG. 1, the light and heat from the light source or heat source 1 (including radiant heat) are condensed or collected by the lens, the shielding plate, or the reflecting plate 2 to form a short peak or A temperature distribution having a shape different from the Gaussian shape, for example, a temperature distribution having a plurality of peaks, is formed, and the end face processing of the optical fiber is performed by melting. In this case, at least one or more annular high temperature regions may be formed in the processing cross section of the optical fiber.

  Further, it is confirmed whether the desired end face state of the optical fiber is formed by the reflection side monitor 4 or the transmission side monitor 5. When monitoring the optical power as the reflection-side monitor 4 that monitors the reflected light from the end face of the optical fiber, the surface state is observed from the incident angle, reflection angle, and power of the light. In particular, when a plurality of detectors are used, the state of the end face can be grasped in detail from the power distribution. When using the thermo viewer, it is possible to grasp the temperature distribution in detail, but since the structure of the end face is not directly monitored, the accuracy is slightly inferior compared with the light detection. In addition, you may use the temperature distribution monitor which monitors the temperature distribution of the process end surface of an optical fiber.

  A laser light source that melts the processing end face of the optical fiber can be used as the light source. In this case, the optical axis of the laser is made to coincide with the axis of the core of the optical fiber. Further, as the lens, a lens having a polarization action that can obtain a light power distribution by laser irradiation in a cross section of the processing end face of the optical fiber that is different from a single peak shape or a Gaussian shape, for example, a polarization action that can obtain two or more peaks is used. be able to. In this case, it is possible to use a lens having a polarizing action in which the optical power distribution by laser irradiation in the cross section of the processing end face of the optical fiber is an annular high temperature region.

  In addition, a heat source that melts the processing end face of the optical fiber can be used as the heat source, and in this case, the radiation direction of the heat source coincides with the axis of the core of the optical fiber. In addition, as a shielding plate and a reflection plate, the heat distribution in the cross-section of the processing end face of the optical fiber can produce a temperature distribution by the heat source that is different from the unimodal shape or Gaussian shape, for example, the radiant heat from the heat source is the processing end face of the optical fiber It is possible to use at least one of a shielding plate and a reflecting plate having a heat-biasing action that can obtain a temperature distribution of two or more peaks. In this case, it is possible to use at least one of a shielding plate and a reflecting plate having a heat-biasing action in which the heat power distribution by the heat source in the cross section of the processing end face of the optical fiber becomes an annular high temperature region.

  Therefore, the optical fiber end face processing apparatus according to the embodiment of the present invention has a temperature distribution that enables end face processing for sealing the holes of hole optical fibers (hole fibers, hole assisted fibers, photonic band gap fibers). Can be formed on the processing end face, and in this case, the temperature in the vicinity of the pores is higher than that of the other portions. Further, since the optical fiber is fixed to the ferrule, a temperature distribution capable of melting and joining the interface between the optical fiber and the ferrule can be formed on the processing end face. Furthermore, a temperature distribution capable of forming a PC (Physical Contact) polished surface can be formed on the processing end surface. Such bonding of the interface between the ferrule and the optical fiber, formation of the PC polished surface, and sealing of the holes (only the hole optical fiber) form a temperature distribution that can be realized simultaneously or in any order.

  2-4 is explanatory drawing which shows the specific example of the optical fiber end surface processing apparatus which concerns on embodiment of this invention. 2 to 4 show specific examples {1} to {9} in which various light sources / heat sources, lenses / shielding plates / reflecting plates, and optical fibers are used.

Example {1}
In Example {1}, a CO ₂ laser with a wavelength of 10.6 μm (an infrared laser such as a dye laser or a free electron laser can also be used) is used as a light source, and Fresnel lenses 11 and 12 (side view, In addition, the front view used 2 sheets of annular shapes, and used the hole assisted fiber (G.657B conformity of nonpatent literature 1) as the optical fiber 13. FIG. The Fresnel lenses 11, 12 are converted into parallel beams by the first lens 11, and an annular (front view) high power region is obtained by the second lens 12, and is located at the position of the hole 15 of the optical fiber 13. Designed to overlap.

  By irradiating the hole 15 of the optical fiber 13 with strong optical power, the position of the hole 15 of the optical fiber 13 becomes a temperature distribution (front view) where the high temperature portion 17 is formed, and the hole 15 is sealed. Is possible. Further, since the portion other than the holes 15 is also irradiated with relatively weak light power, the end face is smoothed, and a PC polished surface (compliant with European standard IEC1300-3-16) can be formed depending on conditions. The end face characteristics after the treatment were connection loss: 0.3 dB and reflection loss: 45 dB. In the end face shape (front view) of the optical fiber 13, 14 is a cladding, and 16 is a core.

-Example {2}
In Example {2}, a CO ₂ laser having a wavelength of 10.6 μm is used as a light source, and six small concave lenses 21 ((a) is a side view and (b) is a front view) are used as a focusing device. A hole assisted fiber (G.657B compliant) was used as 22.

  The six lenses 21 are arranged so as to be aligned with the six holes 24 of the hole assisted fiber 22, and high intensity optical power is irradiated only to the vicinity of the holes 24 of the optical fiber 22. Thus, the temperature distribution (front view) in which the positions of the holes 24 of the optical fiber 22 become the high temperature portion 26 is obtained, and the holes 24 can be sealed with high accuracy. However, alignment in the direction of the rotation axis that was not necessary in the example {1} is required.

  Further, since the portion of the optical fiber 22 other than the hole 24 is irradiated with relatively weak light power, the end face is smoothed, and a PC polished surface (compliant with IEC1300-3-16) can be formed depending on conditions. . The end face characteristics after the treatment were connection loss: 0.4 dB and reflection loss: 42 dB. In the end face shape (front view) of the optical fiber 13, reference numeral 23 denotes a clad and 25 denotes a core.

-Example {3}
In Example {3}, a CO ₂ laser having a wavelength of 10.6 μm is used as a light source, and a Fresnel lens 31 (side view, front view is annular) and a diffraction lens 32 (side view, front view) are used as condensing devices. In the figure, one ring is used, and a hole assisted fiber (G.657B compliant) is used as the optical fiber 33. After conversion to a parallel beam by the first Fresnel lens 31, an annular high power region is obtained by the second diffraction lens 32 and is designed to overlap the position of the hole 35 of the optical fiber 33.

  By irradiating the hole 35 of the optical fiber 33 with a strong optical power, the position of the hole 35 of the optical fiber 33 becomes a temperature distribution (front view) that becomes the high temperature portion 37, and the hole 35 is sealed. Is possible.

  Further, since the portion of the optical fiber 33 other than the hole 35 is irradiated with relatively weak light power, the end surface is smoothed, and a PC polished surface (compliant with IEC1300-3-16) can be formed depending on conditions. . The end face characteristics after the treatment were connection loss: 0.3 dB and reflection loss: 45 dB. In the end face shape (front view) of the optical fiber 13, reference numeral 34 denotes a clad and 36 denotes a core.

-Example {4}
In the example {4}, a CO ₂ laser having a wavelength of 10.6 μm is used as a light source, a Fresnel lens 41 (side view, where the front view is an annular shape) is used as a condensing device, and a hole assembly is used as the optical fiber 42. Steed fiber (G.657B compliant) was used.

  The Fresnel lens 41 is designed so that an annular high power region is obtained and overlaps the position of the hole 44 of the optical fiber 42. By irradiating the hole 44 of the optical fiber 42 with a strong optical power, the position of the hole 44 of the optical fiber 42 becomes a temperature distribution (front view) that becomes the high temperature portion 46, and the hole 44 is sealed. Is possible. Compared with the embodiment {1}, there is a feature that an annular high power region can be realized by one lens 41, but there is also a difficulty in designing.

  Further, since the portion of the optical fiber 42 other than the hole 44 is irradiated with relatively weak light power, the end surface is smoothed, and a PC polished surface (compliant with IEC1300-3-16) can be formed depending on conditions. . The end face characteristics after the treatment were connection loss: 0.4 dB and reflection loss: 42 dB. In the end face shape (front view) of the optical fiber 42, 43 is a cladding and 45 is a core.

-Example {5}
In Example {5}, a CO ₂ laser having a wavelength of 10.6 μm is used as a light source, and a Fresnel lens 51 (side view, front view is annular) and a diffraction lens 52 (side view, front view) are used as condensing devices. In the figure, one ring is used, and a hole assisted fiber (G.657B compliant) is used as the optical fiber 53.

After being converted into a parallel beam by the first Fresnel lens 51, one annular high power region and one middle power region are obtained by the second diffraction lens 52, and the high power region is a hole 55 of the optical fiber 53. The middle power region is designed to overlap the outer edge portion of the optical fiber 53 at the position.

  By irradiating the hole 55 of the optical fiber 53 with a strong optical power, the position of the hole 55 of the optical fiber 53, for example, the position of the ring of 6 to 23 μm around the core 56, for example, is a high temperature part of 1800 ° C. The temperature distribution becomes 57 (front view), and the hole 55 can be sealed. By irradiating the outer edge portion of the optical fiber 53 with medium optical power, the outer edge portion of the optical fiber 53, for example, the annular portion with a radius of 55 μm centered on the core 56, for example, the intermediate temperature portion 59 of 1700 to 1800 ° C. Temperature distribution (front view), which facilitates the formation of a PC polished surface (conforming to IEC1300-3-16).

  In addition, since a relatively weak light power is irradiated to portions other than the holes 55 of the optical fiber 53, a temperature distribution (front view) that becomes a low temperature portion 58 of, for example, 1600 to 1700 ° C. is obtained, and the end face is smoothed. The end face characteristics after the treatment were connection loss: 0.2 dB and reflection loss: 48 dB. In the end face shape (front view) of the optical fiber 53, reference numeral 54 denotes a clad.

-Example {6}
In Example {6}, a CO ₂ laser with a wavelength of 10.6 μm is used as the light source, and the Fresnel lens 61 (side view, front view is annular) and the diffraction lens 62 (side view, front view) are used as the condensing device. In the figure, one ring is used, and a hole assisted fiber (G.657B compliant) is used as the optical fiber 63. The optical fiber 63 is inserted in the ferrule 67. Examples of the ferrule 67 include zirconia, plastic, crystallized glass, and quartz glass. A quartz glass ferrule is desirable for temperature compatibility.

  After being converted into a parallel beam by the first Fresnel lens 61, two annular high power regions are obtained by the second diffractive lens 62. The position of the hole 65 of the optical fiber 63 and the optical fiber 63 and ferrule 67 are obtained. Designed to overlap the interface. By irradiating the hole 65 of the optical fiber 63 with a strong optical power, the position of the hole 65 of the optical fiber 63 becomes a temperature distribution (front view) where the high temperature portion 68 is formed, and the hole 65 is sealed. Is possible. By irradiating the interface between the optical fiber 63 and the ferrule 67 with high-intensity optical power, the interface position between the optical fiber 63 and the ferrule 67 becomes a temperature distribution (front view) where the high temperature portion 68 is formed. Fusion bonding is possible.

  Further, since the portion of the optical fiber 63 other than the holes 65 is irradiated with relatively weak light power, the temperature distribution (front view) of the low temperature portion 69 is obtained, the end face is smoothed, and the PC polished surface ( IEC1300-3-16) can be formed. The end face characteristics after the treatment were connection loss: 0.2 dB and reflection loss: 48 dB. In the end face shape (front view) of the optical fiber 53, 64 is a clad and 66 is a core.

-Example {7}
In Example {7}, a nichrome wire heater (molybdenum, tungsten, carbon heater or the like can be used) is used as a heat source, and a heat shielding plate 71 (side view, front view is annular) is used as a heat collecting device. As the fiber 72, a hole assisted fiber (G.657B compliant) was used. The heat shield plate 71 has an annular hole (installed with a thin bridge or the like for fixing the central shield plate) and has a long introduction portion for increasing directivity.

  The annular hole portion of the heat shielding plate 71 is designed to coincide with the hole 74 portion of the optical fiber 72, and when the hole 74 of the optical fiber 72 is irradiated with strong heat power, The position of the hole 74 of the fiber 72 becomes a temperature distribution (front view) where the high temperature portion 76 is formed, and the vicinity of the hole 74 is melted at a high temperature, so that the hole 74 can be sealed.

  In addition, since a relatively low temperature distribution (front view) is formed in a portion other than the holes 74 of the optical fiber 72, the end surface is slightly melted and smoothed. Depending on conditions, the PC polished surface (IEC1300-3- 16). The end face characteristics after the treatment were connection loss: 0.3 dB and reflection loss: 43 dB. In the end face shape (front view) of the optical fiber 72, 73 is a clad and 75 is a core.

-Example {8}
In Example {8}, a carbon heater was used as a heat source, a heat shielding plate 81 ((a) is a side view, (b) is a front view), and a holey fiber was used as the optical fiber 83. The heat shielding plate 81 is provided with a plurality of annular holes 82 so as to coincide with the holes 84 of the optical fiber 83, and each hole 82 has a long introduction part to enhance directivity. It has.

  A temperature distribution in which the position of the hole 84 of the optical fiber 83 becomes the high temperature part 85 by irradiating the hole 84 of the optical fiber 83 with strong heat power through the hole 82 of the heat shielding plate 81 from the carbon heater. (Front view), and the vicinity of the holes 84 is melted at a high temperature, so that the holes 84 can be sealed with high accuracy. However, alignment in the direction of the rotation axis, which was not necessary in Example {7}, is required.

  In addition, since a relatively low temperature distribution (front view) is formed in a portion other than the hole 84 of the optical fiber 83, the end surface is slightly melted and smoothed. Depending on conditions, the PC polished surface (IEC1300-3- 16). The end face characteristics after the treatment were connection loss: 0.4 dB and reflection loss: 43 dB. The end face shape of the optical fiber 83 represents a front view.

-Example {9}
In Example {9}, a carbon heater was used as a heat source, a radiant heat reflecting plate 91 (side view, front view is annular) was used as a heat collecting device, and a holey fiber was used as the optical fiber 92. The radiant heat reflecting plate 91 has a double hole in an annular shape (a thin bridge or the like is installed to fix the radiant heat reflecting plate 91), and a long and tapered introduction portion for improving directivity and reflection efficiency. It has.

  The annular portion inside the radiant heat reflecting plate 91 is provided with an annular hole so as to coincide with the hole 93 portion of the optical fiber 92, and the optical fiber 92 is passed from the carbon heater through the radiant heat reflecting plate 91. By irradiating a strong heat power to the hole 93 part of this hole, the position of the hole 93 of the optical fiber 92 becomes a temperature distribution (front view) that becomes the high temperature part 94, and the vicinity of the hole 94 is melted at a high temperature. As a result, the hole 94 can be sealed with high accuracy. The annular hole on the outer side of the radiant heat reflecting plate 91 coincides with the outer edge portion of the optical fiber 92, and medium heat power is irradiated from the carbon heater to the outer edge portion of the optical fiber 92 through the radiant heat reflecting plate 91. Thus, the temperature distribution (front view) in which the position of the outer edge portion of the optical fiber 92 becomes the middle temperature portion 96 is obtained, and the outer edge portion of the optical fiber 92 is heated to a medium temperature, thereby causing the PC polished surface (IEC1300-3- 16).

  In addition, since a relatively weak heat power is irradiated to portions other than the holes 94 of the optical fiber 92, a temperature distribution (front view) that becomes the low temperature portion 95 is obtained, and the end surface is smoothed. The end face characteristics after the treatment were connection loss: 0.25 dB and reflection loss: 46 dB. The end face shape of the optical fiber 53 represents a front view.

In any of Examples {1} to {9}, excellent connection characteristics of connection loss: 0.4 dB or less and reflection loss: 40 dB or more were realized, and the effectiveness of the present invention was proved.
In Examples {1} to {9}, the number of holes in the hole fiber is six, but it goes without saying that the same result can be obtained with other numbers of holes. Furthermore, similar characteristics can be obtained even with a solid optical fiber that is not a hole fiber.

  Further, although the connection characteristics are slightly different in the examples {1} to {9}, they do not show the superiority of the configuration because they vary slightly depending on the type of optical fiber and connection conditions. However, a connection loss of 0.4 dB or less and a reflection loss of 40 dB or more are ensured.

  Furthermore, although the temperature distribution is divided into a high temperature part, a medium temperature part, and a low temperature part, there is not necessarily a clear temperature difference at the boundary part. In most cases, the temperature changes smoothly, and the partition at a certain temperature is only separated from the high temperature part (or the middle temperature part or the low temperature part). In addition, it is the temperature at which the glass melts in any of the high temperature part, intermediate temperature part, and low temperature part, indicating that the difference in temperature affects the difference in the melting amount (basically the higher temperature part) Increases the amount of melting).

Furthermore, since with respect to the wavelength of the laser can be towards the short wavelength to reduce the spot size, instead of the CO ₂ laser, 3 [mu] m of HF lasers, CO lasers 5 to 7 .mu.m, InAsSb-based semiconductor 2~5μm Fine processing is possible by using a laser, a 5 to 9 μm PbSSe semiconductor laser, or the like. However, if the wavelength is too short, the transparency of the glass becomes high and the heat conversion efficiency with respect to the optical power is lowered. Therefore, it is necessary to comprehensively judge them. Although a CO ₂ laser is used in this embodiment, it goes without saying that these lasers can be applied to this embodiment.

[Embodiment 2]
FIG. 5 is a configuration explanatory view showing a usage example of the optical fiber end face processing apparatus according to the embodiment of the present invention. In FIG. 5, 101 is an optical fiber end face processing device, 102 is a light source or heat source, 103 is a lens or heat shielding plate or reflector, 104 is a lens, 105 is an optical fiber, 106 is a ferrule, 107 is a hole, and 108 is a core. , 109 is a high temperature part, 110 is a high temperature part, and 111 is a temperature distribution part that increases in temperature as it goes to the outer edge part.

In Embodiment 2 of the present invention, the three steps of sealing the hole of the optical fiber, bonding of the optical fiber and ferrule, and formation of the PC polished surface (if not a hole fiber, bonding of the optical fiber and ferrule, The optical fiber end face processing performed in only two steps of forming the PC polished surface will be described. Here, a CO ₂ laser having a wavelength of 10.6 μm was used as the light source 102, a hole-assisted fiber (G.657B compliant) was used as the optical fiber 105, a Fresnel lens was used as the lens 103, and a quartz glass ferrule was used as the ferrule 106. In this step, the distance between the optical fiber end surface processing apparatus 101 and the end surface of the optical fiber 105 and the position of the lens 104 built in the optical fiber end surface processing apparatus 101 are adjusted, and the temperature distribution on the end surface of the optical fiber 105 is determined. It is realized by controlling.

  In step [1], the optical fiber end surface processing apparatus 101 is located relatively far from the end surface of the optical fiber 105, and is positioned together with the lens 104 so that the high temperature portion 109 of the annular ring coincides with the hole 107 portion of the optical fiber 105. After the adjustment, laser light is emitted from the light source 102 to seal the hole 107 of the optical fiber 105.

  In step [2], the optical fiber end face processing apparatus 101 and the built-in lens 104 are moved toward the end face of the optical fiber 105 so that the high-temperature part 110 of the ring matches the interface between the optical fiber 105 and the ferrule 106. . Thereafter, a laser is irradiated from the light source 102 to join the interface between the optical fiber 105 and the ferrule 106.

  In step [3], the optical fiber end face processing apparatus 101 is further moved closer to the end face side of the optical fiber 105, while the built-in lens 104 is moved away from the end face of the optical fiber 105, so that the outer edge of the ferrule 106 is heated at a high temperature. As a result, the temperature distribution unit 111 is realized in which the temperature gradually decreases as it goes to the center of the optical fiber 105. Thereafter, a laser is irradiated from the light source 102 to realize a PC polished surface.

  After the processes [1] to [3], the connector was formed and the end face characteristics were evaluated. As a result, connection loss: 0.1 dB or less (wavelengths 1.3 μm and 1.55 μm), reflection loss: 50 dB or more Connection characteristics were obtained.

  In the second embodiment, the step [2] is performed after the step [1], but the opposite result can be obtained. Further, in the case of a solid type fiber as the optical fiber, simple end face processing of the optical fiber can be performed by the steps [2] and [3].

  Further, the effects of the second embodiment will be described. Although the process is a three-stage process, the entire process is performed only by moving the optical fiber end face processing device and the built-in lens (both on the same axis in the second embodiment). Therefore, the manufacturing load can be greatly reduced, and the number of parts of the apparatus can be greatly reduced.

  Needless to say, the reflection-side monitor and the transmission-side monitor described in the first embodiment can be applied as means for observing the state of the processing end face of the optical fiber.

  As described above, the optical fiber end face processing apparatus according to the embodiment of the present invention controls the shape of the temperature distribution on the processing end face of the optical fiber in detail, so that (1) the step of fixing the optical fiber in the ferrule , (2) PC polishing-less PC polishing surface formation, and (3) hole-sealing process of optical fiber having holes, simultaneously and with high accuracy by a series of temperature distribution forming processes. It is characterized by doing.

  In order to realize the above characteristics, in the embodiment of the present invention, a temperature distribution having a shape different from a single peak shape or a Gaussian shape is formed. This is because light and radiant heat emitted from a point light source or point heat source generate a single-peak or Gaussian temperature distribution on the processing end face of the optical fiber, and satisfy the melting conditions for realizing the desired processing end face. I want. In particular, in the case of holey fibers, if the temperature at which the holes are sealed is to be realized in a single-peak shape or a Gaussian shape, the melting region becomes wider and becomes spherical, so that the formation of a PC polished surface without polishing is achieved. Is difficult. Therefore, in the embodiment of the present invention, a desired optical fiber end face can be formed by finely controlling the temperature distribution on the processing end face of the optical fiber. As a specific example, it is realized by forming a high temperature region having two or more peaks, an annular high temperature region, or the like.

  Formation of a desired temperature distribution is realized by giving directivity to the propagation of light and heat using a special shape or a plurality of lenses when a light source is used, and a shielding plate or a reflecting plate when a heat source is used.

  There are three heating processes: ferrule and optical fiber bonding, PC polished surface generation, and hole sealing. When three heating processes are performed simultaneously with one heating, the temperature is different in two or three times. The case where it carries out by a profile etc. can be considered. Furthermore, when using a light source and a lens, it is possible to change the high temperature region by changing the focal length of the lens. For example, when there is an annular high temperature region, the diameter and thickness of the ring can be changed by adjusting the focal length.

  Regarding the monitoring of the optical fiber end face formation, in the case of a light source, it is possible to monitor the surface condition by measuring the spatial distribution of reflected light from the end face. Accuracy and the like can be improved.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. Further, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, you may combine suitably the component covering different embodiment.

It is composition explanatory drawing which shows the optical fiber end surface processing apparatus which concerns on embodiment of this invention. It is explanatory drawing which shows the specific example of the optical fiber end surface processing apparatus which concerns on embodiment of this invention. It is explanatory drawing which shows the specific example of the optical fiber end surface processing apparatus which concerns on embodiment of this invention. It is explanatory drawing which shows the specific example of the optical fiber end surface processing apparatus which concerns on embodiment of this invention. It is composition explanatory drawing which shows the usage example of the optical fiber end surface processing apparatus which concerns on embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Light source or heat source, 2 ... Lens or shielding board or reflecting plate, 3 ... Optical fiber, 4 ... Reflection side monitor (reflection side detector), 5 ... Transmission side monitor which monitors the transmitted light after passing through an optical fiber ( Transmitted light power detector).

Claims (10)

Using a laser beam source, an optical fiber end surface processing apparatus for performing end face treatment of the optical fiber by melting the end face of an optical fiber disposed vacancies between the core and the outer edge portion,
A Fresnel lens that converts the laser light output from the laser light source into a parallel beam;
Based on the laser beam converted into a parallel beam by the Fresnel lens, an annular first optical power region having a first intensity and a first diameter, and a second lower than the first intensity. An annular second optical power region having a strength and a second diameter larger than the first diameter is generated, and a hole in the end face of the optical fiber is disposed in the first optical power region. Forming a high-temperature first annular temperature portion for irradiating the position and sealing the hole at the position, and irradiating the outer edge portion of the end face of the optical fiber with the second optical power region. A diffractive lens for forming a second annular temperature part at a temperature lower than the first annular temperature part for polishing the outer edge part on the outer edge part;
Optical fiber end surface processing apparatus characterized by comprising a. The diffraction lens has a third intensity lower than the second intensity based on the laser beam converted into a parallel beam by the Fresnel lens and is different from the first and second diameters. An annular third optical power region having a diameter of is further generated, and the third optical power region is irradiated to a portion other than the hole of the optical fiber end surface, and the optical fiber end surface is smoothed at the portion. The optical fiber end surface processing apparatus according to claim 1, wherein a third annular temperature part that is lower in temperature than the second annular temperature part is formed.   An optical fiber end face processing device that uses a laser light source and melts an end face of an optical fiber in which a hole is arranged between a core and an outer edge portion in the ferrule, thereby performing end face processing of the optical fiber. In
  A Fresnel lens that converts the laser light output from the laser light source into a parallel beam;
  Based on the laser beam converted into a parallel beam by the Fresnel lens, an annular first optical power region having a first intensity and a first diameter, a first intensity and the first intensity An annular second optical power region having a second diameter greater than the diameter, and an annular third optical power having a third diameter lower than the first intensity and different from the first and second diameters. A high-temperature first circle for generating an optical power region and irradiating the first optical power region to a position where the hole of the end face of the optical fiber is disposed to seal the hole at the position. An annular temperature portion is formed, and a second high-temperature annular temperature portion is formed for joining the optical fiber and the ferrule by irradiating the interface between the optical fiber and the ferrule with the second optical power region. In addition, the third optical power region is irradiated to a part other than the holes. For smoothing sites, diffraction lens to form a third annular temperature of the low temperature than the first and second annular temperature portion and
An optical fiber end face processing apparatus comprising:   In an optical fiber end surface processing apparatus that performs end surface processing of an optical fiber by melting the end surface of the optical fiber in which holes are arranged between the core and the outer edge using a heat source,
  Comprising a radiant heat reflector having a plurality of annular holes of different diameters;
  The radiant heat reflecting plate has an annular first heat power region having a first intensity and a first diameter based on heat generated from the heat source, and a second lower than the first intensity. Each having a second diameter larger than the first diameter and having a second diameter larger than the first diameter, and a hole in the end face of the optical fiber is disposed in the first heat power area. Forming a high-temperature first annular temperature portion for irradiating the position and sealing the hole at the position, and irradiating the outer edge portion of the end face of the optical fiber with the second thermal power region Then, a second annular temperature part having a temperature lower than that of the first annular temperature part for polishing the outer edge part is formed on the outer edge part.   The radiant heat reflecting plate has a third strength lower than the second strength and a third diameter different from the first and second diameters based on heat generated from the heat source. An annular third thermal power region is further generated, and the third thermal power region is irradiated to a part other than the holes of the optical fiber end face, and the optical fiber end face is smoothed at the part. The optical fiber end face processing apparatus according to claim 4, wherein a third annular temperature part having a temperature lower than that of the second annular temperature part is formed.   In an optical fiber end surface processing method for performing an end surface processing of an optical fiber by melting the end surface of the optical fiber in which holes are arranged between the core and the outer edge using a laser light source,
  Using a Fresnel lens, the laser light output from the laser light source is converted into a parallel beam,
  An annular first optical power region having a first intensity and a first diameter based on the laser beam converted into a parallel beam by the Fresnel lens using a diffraction lens, and the first A second optical power region having an annular shape having a second intensity lower than the first diameter and having a second diameter larger than the first diameter, and the first optical power range is defined as the optical fiber. A high temperature first annular temperature portion is formed to irradiate a position where the hole of the end face is disposed to seal the hole at the position, and the second optical power region is used as the optical fiber. An end face of an optical fiber, wherein a second annular temperature portion having a temperature lower than that of the first annular temperature portion is formed on the outer edge portion to irradiate the outer edge portion of the end face and polish the outer edge portion. Processing method. Based on the laser beam converted into a parallel beam by the Fresnel lens using the diffraction lens, it has a third intensity lower than the second intensity and is different from the first and second diameters. An annular third optical power region having a third diameter is further generated, and the third optical power region is irradiated to a portion other than the holes of the optical fiber end surface, and the optical fiber end surface is applied to the portion. The optical fiber end surface processing method according to claim 6, further comprising forming a third annular temperature portion that is lower in temperature than the second annular temperature portion for smoothing.   An optical fiber end face processing method for processing an end face of an optical fiber using a laser light source and melting the end face of the optical fiber in which holes are arranged between the core and the outer edge portion in the ferrule. In
  Using a Fresnel lens, the laser light output from the laser light source is converted into a parallel beam,
  Based on the laser beam converted into a parallel beam by the Fresnel lens using a diffraction lens, an annular first optical power region having a first intensity and a first diameter; An annular second optical power region having a second diameter that is greater than the first diameter, and a third diameter that is lower than the first intensity and different from the first and second diameters. Generating an annular third optical power region, and irradiating the first optical power region to a position where the hole of the end face of the optical fiber is disposed to seal the hole at the position. Forming a high temperature first annular temperature portion, and irradiating the interface between the optical fiber and the ferrule with the second optical power region to join the optical fiber and the ferrule. And forming the third optical power region below the holes. Sites in order to smooth the site by irradiating a to form a third annular temperature of the low temperature than the first and second annular temperature portion
An optical fiber end face processing method.   In the optical fiber end surface processing method for performing the end surface processing of the optical fiber by melting the end surface of the optical fiber in which holes are arranged between the core and the outer edge portion using a heat source,
  An annular first heat power having a first strength and a first diameter based on heat generated from the heat source, using a radiant heat reflector having a plurality of annular holes with different diameters. And a second annular heat power region having a second intensity lower than the first intensity and having a second diameter larger than the first diameter, and the first heat A power region is irradiated to the position where the hole of the end face of the optical fiber is disposed to form a high temperature first annular temperature portion for sealing the hole at the position, and the second heat A second annular temperature part lower than the first temperature part is formed on the outer edge part to irradiate the outer edge part of the optical fiber end face and polish the outer edge part. An optical fiber end face processing method.   Based on the heat generated from the heat source using the radiant heat reflector, a third diameter having a third intensity lower than the second intensity and different from the first and second diameters. An annular third thermal power region is further generated, and the third thermal power region is irradiated to a portion other than the holes of the optical fiber end surface to smooth the optical fiber end surface at the portion. The optical fiber end face processing method according to claim 9, wherein a third annular temperature portion having a temperature lower than that of the second annular temperature portion is formed.

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