CA2041212A1 - Process for producing an optical coupler for polymer optical waveguides - Google Patents
Process for producing an optical coupler for polymer optical waveguidesInfo
- Publication number
- CA2041212A1 CA2041212A1 CA002041212A CA2041212A CA2041212A1 CA 2041212 A1 CA2041212 A1 CA 2041212A1 CA 002041212 A CA002041212 A CA 002041212A CA 2041212 A CA2041212 A CA 2041212A CA 2041212 A1 CA2041212 A1 CA 2041212A1
- Authority
- CA
- Canada
- Prior art keywords
- plastic tube
- shrink
- sleeve
- optical
- plastic
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/24—Coupling light guides
- G02B6/26—Optical coupling means
- G02B6/28—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals
- G02B6/2804—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals forming multipart couplers without wavelength selective elements, e.g. "T" couplers, star couplers
- G02B6/2856—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals forming multipart couplers without wavelength selective elements, e.g. "T" couplers, star couplers formed or shaped by thermal heating means, e.g. splitting, branching and/or combining elements
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/24—Coupling light guides
- G02B6/26—Optical coupling means
- G02B6/28—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals
- G02B6/2804—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals forming multipart couplers without wavelength selective elements, e.g. "T" couplers, star couplers
- G02B6/2808—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals forming multipart couplers without wavelength selective elements, e.g. "T" couplers, star couplers using a mixing element which evenly distributes an input signal over a number of outputs
Abstract
Abstract of the Disclosure Process for producing an optical coupler for polymer optical waveguides Process for producing an optical coupler for polymer optical waveguides by arranging the optical waveguides in the same sense and bundling them by means of a plastic shrink-on sleeve. In this process, two to 105 polymer optical waveguides are arranged in the same sense and bundled and a plastic tube is put over the mixing region.
Then a piece of plastic shrink-on sleeve is pushed over the plastic tube and the shrink-on sleeve is heated to a temperature at which it contracts. The shrinkage tempera-ture of the shrink-on sleeve is inside the thermoelastic temperature range of the plastic tube. The optical wave-guide bundle may be stretched during or after heating.
Then a piece of plastic shrink-on sleeve is pushed over the plastic tube and the shrink-on sleeve is heated to a temperature at which it contracts. The shrinkage tempera-ture of the shrink-on sleeve is inside the thermoelastic temperature range of the plastic tube. The optical wave-guide bundle may be stretched during or after heating.
Description
~Q~:~212 HOECHST AKTIENGESELLSCHAFT DCh.SY/gm HOE 90/F 128 Description Process for producing an optical coupler for polymer optical waveguides The invention relates to an economically beneficial process for producing optical couplers which have a high mechanical stability and are very r~sistant to thermal and weathering effects.
In passive optical waveguide networks, couplers serve as optical components for distributing the light signals from incoming optical waveguides over outgoing optical waveguides. Such couplers are composed of a transparent body which is connected to optical waveguides at the light input and at the light output side. In addition to couplers which are produced by bonding or fusing trans-parent moldings to optical waveguides, couplers are also known which are produced by twisting bundles of optical waveguides and stretching the twisted place (cf. Agarwal, Fiber Integr. Optics 6 (1) 27-53, 1987).
The production of such composite couplers is, however, complex and expensive; in addition, the throughput attenuation of such known couplers i8 difficult to reproduce ~o that the power varies by more than 1 d~
between the various output fiber~.
Furthermore, couplers are known in which fiber bundles made of polymer optical waveguides are fused together by means of a shrink-on sleeve (DE-A-3,737,930, WO-89/02608). In a process in accordance with W0-89/02608, only incomplete contact is produced between the fused core fibers, the shrink-on sleeve and a so-called "filler rod", so that a disturbed core-cladding boundary layer is produced which results in large optical losses.
In passive optical waveguide networks, couplers serve as optical components for distributing the light signals from incoming optical waveguides over outgoing optical waveguides. Such couplers are composed of a transparent body which is connected to optical waveguides at the light input and at the light output side. In addition to couplers which are produced by bonding or fusing trans-parent moldings to optical waveguides, couplers are also known which are produced by twisting bundles of optical waveguides and stretching the twisted place (cf. Agarwal, Fiber Integr. Optics 6 (1) 27-53, 1987).
The production of such composite couplers is, however, complex and expensive; in addition, the throughput attenuation of such known couplers i8 difficult to reproduce ~o that the power varies by more than 1 d~
between the various output fiber~.
Furthermore, couplers are known in which fiber bundles made of polymer optical waveguides are fused together by means of a shrink-on sleeve (DE-A-3,737,930, WO-89/02608). In a process in accordance with W0-89/02608, only incomplete contact is produced between the fused core fibers, the shrink-on sleeve and a so-called "filler rod", so that a disturbed core-cladding boundary layer is produced which results in large optical losses.
- 2 - 2~412~2 A further ma~or problem of many couplers, for example of the ~biconical taper~ coupler or also the combination of the shrink-on sleeve technique and the ~biconical taper"
process, is an only inadequate mechanical stability, in particular in the vicinity of the mixing region, which can be reduced only by supporting measures. In order to meet the stability requirements demanded in automobile construction it is therefore necessary to fix the couplers produced in po~ition in special housings.
The object was therefore to find a procefis by which mechanically stable couplers can be simply and inexpen-sively produced and which yields couplers having low output attenuations and low power variations between the output fibers.
In this process there should be the possibility, depend-ing on field of application, either of starting from finished optical waveguides from which the surrounding cladding material i8 removed only in the ~ixing region or, alternatively, of alfio producing compact optical waveguide bundles in which any removal of the cladding can be dispensed with.
It was found that a coupler which is Etable to external effects and has minimum variations between the individual output fibers can be produced in a simple way by sur-rounding the optical waveguides in the mixing region witha plastic tube over which a shrink-on sleeve is pulled on in a subsequent step.
~or the process according to the invention, two to 105 polymer optical waveguides are arranged in t~e same sense and bundled, in which process the optical waveguides may optionally be twisted, a plastic tube is put over the mixing region and then a piece of plastic shrink-on sleeve is pushed over the tube. The sleeve is caused to shrink by heating it.
The plastic tube increases the ~tability of the mixing region so that it is protected against external effects, for example impact, shock or bending loads. The tube must not be completely stiff but must be flexible to a certain extent, i.e. adapt to the optical waveguides in the mixing region on bending, but protect them against fracture. However, the plastic tube also protects the mixing region against thermal and climatic effects 80 that such couplers exhibit very low deviations in at-tenuation even after exposures to high temperature.
Suitable materials for such plactic tubes are generallyall the highly transparent polymer~ whose refractive index is less than the refractive index of the fibers, for example polymethyl methacrylate (PMMA), poly-4-methylpentene, polytetrafluoroethylene or fluorinatedpolymers.
A condition for a successful fusion i8 the matching of the mechanical and thermodynamic properties of optical waveguide and plastic tube. When the optical waveguide and plastic tube are heated, they convert from the gla~sy state to a thermoelastic state. The thermoelastic state is followed by a thermoplastic state. A~ the temperature rises, the plastic tube should convert to the thermo-ela~tic ~tate first, while the optical waveguide should only complete this transition at a higher temperature.
However, before the pla~tic tube converts to the thermo-plastic state, the optical waveguides must already be in the thermoela~tic state. This results in a good optical contact of plastic tube and optical waveguide and at the same time, the cladding material i8 prevented from getting between the guides. The Yarious temperature ranges can be matched to one another by altering the molecular weight of optical waveguide and plastic tube.
If the shrinkage temperature of the shrink-on sleeve is inside the thermoelastic temperature range of the plastic tube, a dense bundling of tube and conductor~ occurs.
During the fusion, the fiber bundle surrounded by the 4 ~ 1 2 shrink-on sleeve and plastic tube may be stretched symmetrically or asymmetrically during or after heating, with the result that a double conical profile with a waist in the middle (biconical taper) forms. This double conical profile can also be achieved without stretching by heating the center of the 6hrink-on ~leeve more 6trongly than the ends.
The shrinkage process of the shrink-on slee~e results in the deformation of the plastic tube, as a result of which the fused polymer optical waveguide bundle is hermetic-ally sealed off.
In the process according to the invention, the refractive index of the plastic tube should be less than the refrac-tive index of the core fiber 3ince it serves as an optical cladding for the mixing region. In this case, the original cladding material is removed from the fiber before the tube is pulled on in the mixing region.
An advantage of this process is that removal of the ~hrink-on sleeve and subsequent lacquering of the mixing region can be omitted ~ince the plastic tube takes on the function of the optical cladding completely.
An additional reduction of the attenuation losses can for example be achieved by mirror-coating the plastic tube by vapor-coating with a metal, in particular aluminum, or by wrapping the non-vapor-coated tube in a mirror-coated plastic film.
The process described is, however, also suitable for producing compact optical waveguide bundles, for which purpose a prior removal of the optical cladding of the optical waveguides i8 unnecessary.
The plastic tube has a length of 10 to 100 mm, preferably 40 to ~0 mm, and an internal diameter of 1 to 50 mm, preferably 3 to 10 mm. In the preferred embodiment, the _ 5 _ 2~41212 wall thickness is 0.5 to 25 mm, in particular 1 to 5 mm.
Care should be taken to ensure that the internal surface of the tube is as smooth as possible.
Shrink-on sleeves which are suitable for the process according to the invention are described, for example, in DE-A-3,737,930 and W0-89/02608.
The shrink-on sleeve may be black, transparent or colored. Since the shrink-on sleeve does not serve as optical cladding, the refractive index of the shrink-on sleeve does not play any role in this type of manufac-ture. It is also possible to u~e a shrink-on sleeve whose in~ide wall is coated with a thermoplastic material. The shrink-on sleeve with internal coating is in ~eneral composed of a polyolefin.
Dual ~hrink-on sleeves may also be used for the process according to the invention. These sleeves are compo~ed of an inner and outer shrink-on sleeve. When the shrinkage temperature of the outer sleeve is reached, the inner sleeve is already thermoplastic. The pressure which the outer shrink-on sleeve exerts is sufficient in order to produce a good ~oint between shrink-on sleeve, pla~tic tube and fibers.
The shrink-on sleeve normally has a length of 10 to 200 mm, preferably 50 to 100 mm, and has a diameter of 0.5 to 60 n~, in particular 1 to 20 mm.
The conventional materials for shrink-on sleeves, for example polyolefins, vinylidene fluoride or copolymers containing vinylidene fluoride or silicon rubber, begin, in general, to shrink at temperatures between 100 and 300C, and during this process, the sleeve reduces in a ratio of 1.2:1 to about 4:1, which is dependent on the type of ~hrink-on sleeve.
Couplers in which both the input and the output fibers - 6 ~ 2 -lie in one direction, i.e. the coupling region is bent in a U shape, are used, for example, in the automobile industry. Such bent couplers are particularly susceptible to external mechanical effects in the mixing range which is already stressed as it is. It is precisely as a result of the plastic tube that such specially shaped couplers acquire a high support in this region, with the result that they are particularly resistant to impact, pressure and torsion loadings.
To summarize, it may be ~tated that coupler~ having a particularly high mechanical stability can be produced by the process according to the invention. The plastic tube surrounding the optical waveguides gives the optical fiber a particularly effective protection against all external effects such as, for example, oil, dust or moisture and, in addition, has a very good resistance to thermal and climatic effects.
Example 1 Production of a 7 x 7 star coupler with transmission mixer The optical cladding was removed by means of petrol in a 5 cm region in the case of seven 0.5 m plastic optical waveguides made of polycarbonate and having a diameter of 1 mm each. Then a thin PMMA tube (n = 1.492) was pushed over this region. The refractive index of the fibers was n = 1.585. The PMMA tube had an internal diameter of 3 mm, a wall thickness of 1 mm and a length of 5 cm. Then a 7 cm long transparent shrink-on sleeve made of poly-vinylidene fluoride and having an internal diameter of 6.4 mm was put over the PMMA tube and the fibexs.
To ~eparate the heating system and the shrink-on sleeve, a 7.5 cm long glass tube having an internal diameter of 7 mm was pulled over shrink-on sleeve, PMMA tube and fibers and the fibers were fixed in position. In the - 7 ~
region of the shrink-on sleeve or of the PMMA tube, the temperature was increased to 195C. When this temperature was reached, the shrink-on sleeve began to shrink and the PMMA tube with the fibers, whose softening temperature was below 195C, began to fuse. The fused region (termed mixer rod~ had a circular shape with a length 1 = 2.5 cm and a diameter d ~ 3 mm. Since the PMMA tube has a lower refractive index than the polycarbonate fibers (n =
1.585), the PMMA tube acts simultaneously as optical cladding in addition to its stabilizing action. At the mixer rod/PMMA tube boundary layer, the light traveling in the mixer was totally reflected, with the result that almost no light could penetrate to the outside. After removing the glass tube, a mechanically stable star coupler is obtained.
The star coupler was tested for its refiistance to cyclic thermal loading. For this purpose, the coupler was built into a climatic chamber and heat-treated for one week in an eight hour cycle between -40C and +100C. The change in attenuation was 0.5 dB.
The 7 x 7 star coupler with the transmission mixer had an excess 10BS of 2.0 dB, with a power variation between any output fibers of 1.5 dB.
ExAmple 2 A transmission star coupler was produced in an analogous way to Example 1. The mixer rod was heated again to 180C
by means of a hot-air fiource and bent into a U shape.
The measured excess loss was 2.5 dB, with a power varia-tion between any output fiber~ of 2 dB.
The transmission star coupler was tested for its thermal resistance under the same conditions as the coupler from Example 1. Here again, the attenuation changes were only slight: +0.6 dB. Couplers produced in this way exhibited - 8 - ~ 212 a high torsional load carrying capacity.
Example 3 A 7 x 7 star coupler was produced in an analogous way to Example 1. In order to obtain lower attenuation losses, a polymethyl methacrylate tube vapor-coated with aluminum was used.
The transmission star coupler with a mirror-coated mixing region had an excess loss of 1.7 dB, with a power varia-tion between the output fibers of 1.5 dB.
The difference in attenuation after a thermal loadinq, analogous ts Example 1 and Example 2, was 0.6 dB.
~x4mple 4 A 7 x 7 star coupler based on ~tretched PMMA fiber~
(PMMA: n = 1.492) is produced in a similar manner to Example 1. As a departure from Example 1, the optical cladding is removed with a toluene/acetone solution (2:1). The plastic tube is composed of a fluorinated polymer having a refractive index of n = 1.37. The existing arrangement, composed of the fibers, the plastic tube and the shrink-on sleeve, is heated in a manner such that the temperature in the center of the tube is approximately 190C, while the temperature in the edge region is approximately 10C lower. This temperature control results in an axial shrin~.age of the stretched polymer optical fibers. Since the central part of the fused f ibers are in a thermoplastic state and the outer region in a thermoelastic state, the development of a biconical shape inside the plastic tu~e is brought about.
The radial swelling of the fibers which normally occurs in the edge region is suppressed by the shrinkage force of the shrink-on sleeve.
The transmission star coupler so produced has a very low 2~ 212 _ 9 _ power variation of 1.3 dB. The excess loss i~ in the region of ~.5 dB.
The difference in attenuation wa6 only 0.5 dB in the ca~e of a cyclic thermal loading (from -40C to +857C).
process, is an only inadequate mechanical stability, in particular in the vicinity of the mixing region, which can be reduced only by supporting measures. In order to meet the stability requirements demanded in automobile construction it is therefore necessary to fix the couplers produced in po~ition in special housings.
The object was therefore to find a procefis by which mechanically stable couplers can be simply and inexpen-sively produced and which yields couplers having low output attenuations and low power variations between the output fibers.
In this process there should be the possibility, depend-ing on field of application, either of starting from finished optical waveguides from which the surrounding cladding material i8 removed only in the ~ixing region or, alternatively, of alfio producing compact optical waveguide bundles in which any removal of the cladding can be dispensed with.
It was found that a coupler which is Etable to external effects and has minimum variations between the individual output fibers can be produced in a simple way by sur-rounding the optical waveguides in the mixing region witha plastic tube over which a shrink-on sleeve is pulled on in a subsequent step.
~or the process according to the invention, two to 105 polymer optical waveguides are arranged in t~e same sense and bundled, in which process the optical waveguides may optionally be twisted, a plastic tube is put over the mixing region and then a piece of plastic shrink-on sleeve is pushed over the tube. The sleeve is caused to shrink by heating it.
The plastic tube increases the ~tability of the mixing region so that it is protected against external effects, for example impact, shock or bending loads. The tube must not be completely stiff but must be flexible to a certain extent, i.e. adapt to the optical waveguides in the mixing region on bending, but protect them against fracture. However, the plastic tube also protects the mixing region against thermal and climatic effects 80 that such couplers exhibit very low deviations in at-tenuation even after exposures to high temperature.
Suitable materials for such plactic tubes are generallyall the highly transparent polymer~ whose refractive index is less than the refractive index of the fibers, for example polymethyl methacrylate (PMMA), poly-4-methylpentene, polytetrafluoroethylene or fluorinatedpolymers.
A condition for a successful fusion i8 the matching of the mechanical and thermodynamic properties of optical waveguide and plastic tube. When the optical waveguide and plastic tube are heated, they convert from the gla~sy state to a thermoelastic state. The thermoelastic state is followed by a thermoplastic state. A~ the temperature rises, the plastic tube should convert to the thermo-ela~tic ~tate first, while the optical waveguide should only complete this transition at a higher temperature.
However, before the pla~tic tube converts to the thermo-plastic state, the optical waveguides must already be in the thermoela~tic state. This results in a good optical contact of plastic tube and optical waveguide and at the same time, the cladding material i8 prevented from getting between the guides. The Yarious temperature ranges can be matched to one another by altering the molecular weight of optical waveguide and plastic tube.
If the shrinkage temperature of the shrink-on sleeve is inside the thermoelastic temperature range of the plastic tube, a dense bundling of tube and conductor~ occurs.
During the fusion, the fiber bundle surrounded by the 4 ~ 1 2 shrink-on sleeve and plastic tube may be stretched symmetrically or asymmetrically during or after heating, with the result that a double conical profile with a waist in the middle (biconical taper) forms. This double conical profile can also be achieved without stretching by heating the center of the 6hrink-on ~leeve more 6trongly than the ends.
The shrinkage process of the shrink-on slee~e results in the deformation of the plastic tube, as a result of which the fused polymer optical waveguide bundle is hermetic-ally sealed off.
In the process according to the invention, the refractive index of the plastic tube should be less than the refrac-tive index of the core fiber 3ince it serves as an optical cladding for the mixing region. In this case, the original cladding material is removed from the fiber before the tube is pulled on in the mixing region.
An advantage of this process is that removal of the ~hrink-on sleeve and subsequent lacquering of the mixing region can be omitted ~ince the plastic tube takes on the function of the optical cladding completely.
An additional reduction of the attenuation losses can for example be achieved by mirror-coating the plastic tube by vapor-coating with a metal, in particular aluminum, or by wrapping the non-vapor-coated tube in a mirror-coated plastic film.
The process described is, however, also suitable for producing compact optical waveguide bundles, for which purpose a prior removal of the optical cladding of the optical waveguides i8 unnecessary.
The plastic tube has a length of 10 to 100 mm, preferably 40 to ~0 mm, and an internal diameter of 1 to 50 mm, preferably 3 to 10 mm. In the preferred embodiment, the _ 5 _ 2~41212 wall thickness is 0.5 to 25 mm, in particular 1 to 5 mm.
Care should be taken to ensure that the internal surface of the tube is as smooth as possible.
Shrink-on sleeves which are suitable for the process according to the invention are described, for example, in DE-A-3,737,930 and W0-89/02608.
The shrink-on sleeve may be black, transparent or colored. Since the shrink-on sleeve does not serve as optical cladding, the refractive index of the shrink-on sleeve does not play any role in this type of manufac-ture. It is also possible to u~e a shrink-on sleeve whose in~ide wall is coated with a thermoplastic material. The shrink-on sleeve with internal coating is in ~eneral composed of a polyolefin.
Dual ~hrink-on sleeves may also be used for the process according to the invention. These sleeves are compo~ed of an inner and outer shrink-on sleeve. When the shrinkage temperature of the outer sleeve is reached, the inner sleeve is already thermoplastic. The pressure which the outer shrink-on sleeve exerts is sufficient in order to produce a good ~oint between shrink-on sleeve, pla~tic tube and fibers.
The shrink-on sleeve normally has a length of 10 to 200 mm, preferably 50 to 100 mm, and has a diameter of 0.5 to 60 n~, in particular 1 to 20 mm.
The conventional materials for shrink-on sleeves, for example polyolefins, vinylidene fluoride or copolymers containing vinylidene fluoride or silicon rubber, begin, in general, to shrink at temperatures between 100 and 300C, and during this process, the sleeve reduces in a ratio of 1.2:1 to about 4:1, which is dependent on the type of ~hrink-on sleeve.
Couplers in which both the input and the output fibers - 6 ~ 2 -lie in one direction, i.e. the coupling region is bent in a U shape, are used, for example, in the automobile industry. Such bent couplers are particularly susceptible to external mechanical effects in the mixing range which is already stressed as it is. It is precisely as a result of the plastic tube that such specially shaped couplers acquire a high support in this region, with the result that they are particularly resistant to impact, pressure and torsion loadings.
To summarize, it may be ~tated that coupler~ having a particularly high mechanical stability can be produced by the process according to the invention. The plastic tube surrounding the optical waveguides gives the optical fiber a particularly effective protection against all external effects such as, for example, oil, dust or moisture and, in addition, has a very good resistance to thermal and climatic effects.
Example 1 Production of a 7 x 7 star coupler with transmission mixer The optical cladding was removed by means of petrol in a 5 cm region in the case of seven 0.5 m plastic optical waveguides made of polycarbonate and having a diameter of 1 mm each. Then a thin PMMA tube (n = 1.492) was pushed over this region. The refractive index of the fibers was n = 1.585. The PMMA tube had an internal diameter of 3 mm, a wall thickness of 1 mm and a length of 5 cm. Then a 7 cm long transparent shrink-on sleeve made of poly-vinylidene fluoride and having an internal diameter of 6.4 mm was put over the PMMA tube and the fibexs.
To ~eparate the heating system and the shrink-on sleeve, a 7.5 cm long glass tube having an internal diameter of 7 mm was pulled over shrink-on sleeve, PMMA tube and fibers and the fibers were fixed in position. In the - 7 ~
region of the shrink-on sleeve or of the PMMA tube, the temperature was increased to 195C. When this temperature was reached, the shrink-on sleeve began to shrink and the PMMA tube with the fibers, whose softening temperature was below 195C, began to fuse. The fused region (termed mixer rod~ had a circular shape with a length 1 = 2.5 cm and a diameter d ~ 3 mm. Since the PMMA tube has a lower refractive index than the polycarbonate fibers (n =
1.585), the PMMA tube acts simultaneously as optical cladding in addition to its stabilizing action. At the mixer rod/PMMA tube boundary layer, the light traveling in the mixer was totally reflected, with the result that almost no light could penetrate to the outside. After removing the glass tube, a mechanically stable star coupler is obtained.
The star coupler was tested for its refiistance to cyclic thermal loading. For this purpose, the coupler was built into a climatic chamber and heat-treated for one week in an eight hour cycle between -40C and +100C. The change in attenuation was 0.5 dB.
The 7 x 7 star coupler with the transmission mixer had an excess 10BS of 2.0 dB, with a power variation between any output fibers of 1.5 dB.
ExAmple 2 A transmission star coupler was produced in an analogous way to Example 1. The mixer rod was heated again to 180C
by means of a hot-air fiource and bent into a U shape.
The measured excess loss was 2.5 dB, with a power varia-tion between any output fiber~ of 2 dB.
The transmission star coupler was tested for its thermal resistance under the same conditions as the coupler from Example 1. Here again, the attenuation changes were only slight: +0.6 dB. Couplers produced in this way exhibited - 8 - ~ 212 a high torsional load carrying capacity.
Example 3 A 7 x 7 star coupler was produced in an analogous way to Example 1. In order to obtain lower attenuation losses, a polymethyl methacrylate tube vapor-coated with aluminum was used.
The transmission star coupler with a mirror-coated mixing region had an excess loss of 1.7 dB, with a power varia-tion between the output fibers of 1.5 dB.
The difference in attenuation after a thermal loadinq, analogous ts Example 1 and Example 2, was 0.6 dB.
~x4mple 4 A 7 x 7 star coupler based on ~tretched PMMA fiber~
(PMMA: n = 1.492) is produced in a similar manner to Example 1. As a departure from Example 1, the optical cladding is removed with a toluene/acetone solution (2:1). The plastic tube is composed of a fluorinated polymer having a refractive index of n = 1.37. The existing arrangement, composed of the fibers, the plastic tube and the shrink-on sleeve, is heated in a manner such that the temperature in the center of the tube is approximately 190C, while the temperature in the edge region is approximately 10C lower. This temperature control results in an axial shrin~.age of the stretched polymer optical fibers. Since the central part of the fused f ibers are in a thermoplastic state and the outer region in a thermoelastic state, the development of a biconical shape inside the plastic tu~e is brought about.
The radial swelling of the fibers which normally occurs in the edge region is suppressed by the shrinkage force of the shrink-on sleeve.
The transmission star coupler so produced has a very low 2~ 212 _ 9 _ power variation of 1.3 dB. The excess loss i~ in the region of ~.5 dB.
The difference in attenuation wa6 only 0.5 dB in the ca~e of a cyclic thermal loading (from -40C to +857C).
Claims (14)
1. A process for producing an optical coupler for polymer optical waveguides by arranging the optical waveguides in the same sense and bundling them by means of a plastic shrink-on sleeve, which process comprises arranging two to 105 polymer optical wave-guides in the same sense and bundling them, putting a plastic tube over the mixing region, then pushing a piece of plastic shrink-on sleeve over the plastic tube and heating the shrink-on tube to a temperature at which it contracts.
2. The process as claimed in claim 1, wherein the plastic tube converts to the thermoelastic state before the polymer optical waveguides, but the latter still complete the transition to the thermo-elastic state before the transition of the tube material to the thermoplastic state.
3. The process as claimed in at least one of claims 1 to 2, wherein the shrinkage temperature of the shrink-on sleeve is inside the thermoelastic temper-ature range of the plastic tube.
4. The process as claimed in at least one of claims 1 to 3, wherein the optical waveguide bundle is stretched during or after heating.
5. The process as claimed in at least one of claims 1 to 4, wherein the shrink-on sleeve is heated more strongly in the center than at the ends.
6. The process as claimed in at least one of claims 1 to 5, wherein the refractive index of the plastic tube is less than the refractive index of the core fiber.
7. The process as claimed in at least one of claims 1 to 6, wherein the optical waveguides are free of cladding material at the joint and the plastic tube serves as optical cladding for the mixing region of the coupler.
8. The process as claimed in claim 7, wherein the plastic tube is mirror-coated on the inside.
9. The process as claimed in claim 7, wherein the plastic tube is additionally wrapped in a mirror-coated plastic film.
10. The process as claimed in at least one of claims 1 to 9, wherein the length of the plastic tube is in the range from 10 to 100 mm, preferably in the range from 40 to 60 mm.
11. The process as claimed in at least one of claims 1 to 10, wherein the internal diameter of the plastic tube is in the range from 1 to 50 mm, preferably in the range from 3 to 10 mm.
12. The process as claimed in at least one of claims 1 to 11, wherein the plastic tube has a wall thickness in the range from 0.5 to 5 mm, preferably in the range from 1 to 2 mm.
13. Optical coupler produced by a process as claimed in at least one of claims 1 to 12, wherein the mixing region has a high mechanical strength and stability and is particularly temperature and weathering resistant.
14. Optical coupler as claimed in claim 13, wherein the mixing region may have a bent shape.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE4013307A DE4013307A1 (en) | 1990-04-26 | 1990-04-26 | METHOD FOR PRODUCING AN OPTICAL COUPLER FOR POLYMER LIGHTWAVE GUIDE |
| DEP4013307.9 | 1990-04-26 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2041212A1 true CA2041212A1 (en) | 1991-10-27 |
Family
ID=6405133
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002041212A Abandoned CA2041212A1 (en) | 1990-04-26 | 1991-04-25 | Process for producing an optical coupler for polymer optical waveguides |
Country Status (14)
| Country | Link |
|---|---|
| US (1) | US5185832A (en) |
| EP (1) | EP0454107B1 (en) |
| JP (1) | JP3044085B2 (en) |
| KR (1) | KR910018823A (en) |
| CN (1) | CN1056172A (en) |
| AT (1) | ATE131288T1 (en) |
| AU (1) | AU647468B2 (en) |
| CA (1) | CA2041212A1 (en) |
| DE (2) | DE4013307A1 (en) |
| DK (1) | DK0454107T3 (en) |
| ES (1) | ES2082880T3 (en) |
| GR (1) | GR3018523T3 (en) |
| IE (1) | IE70746B1 (en) |
| PT (1) | PT97464B (en) |
Families Citing this family (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB9015775D0 (en) * | 1990-07-18 | 1990-09-05 | British Telecomm | Optical fibre coupler |
| US6292610B1 (en) | 1996-07-08 | 2001-09-18 | Equitech Int'l Corporation | Fiber optic probe and coupler assembly |
| US5978534A (en) * | 1996-07-08 | 1999-11-02 | Equitech Int'l Corporation | Fiber optic raman probe and coupler assembly |
| US5774610A (en) * | 1996-07-08 | 1998-06-30 | Equitech Int'l Corporation | Fiber optic probe |
| CN1317577C (en) * | 2005-04-21 | 2007-05-23 | 上海大学 | 1XN plastic optical fibre coupler |
| US9778188B2 (en) * | 2009-03-11 | 2017-10-03 | Industrial Technology Research Institute | Apparatus and method for detection and discrimination molecular object |
| US9482615B2 (en) * | 2010-03-15 | 2016-11-01 | Industrial Technology Research Institute | Single-molecule detection system and methods |
| US8865077B2 (en) | 2010-06-11 | 2014-10-21 | Industrial Technology Research Institute | Apparatus for single-molecule detection |
| US8865078B2 (en) | 2010-06-11 | 2014-10-21 | Industrial Technology Research Institute | Apparatus for single-molecule detection |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5666812A (en) * | 1979-11-02 | 1981-06-05 | Fujitsu Ltd | Connecting method of optical fiber |
| US4783137A (en) * | 1983-11-15 | 1988-11-08 | Kosman Karel J | Fiber optic coupling system |
| US4822127A (en) * | 1986-06-16 | 1989-04-18 | Shiley Incorporated | Multi-channel optical transmission system |
| JPH03500216A (en) * | 1987-09-14 | 1991-01-17 | アスター・コーポレーション | fiber optic coupler |
| DE3737930A1 (en) * | 1987-11-07 | 1989-05-18 | Hoechst Ag | METHOD FOR PRODUCING AN OPTICAL COUPLER FOR POLYMER LIGHTWAVE GUIDE |
| DE3833369A1 (en) * | 1988-09-29 | 1990-04-05 | Siemens Ag | Method for connecting two optical waveguides and device for carrying out the method |
-
1990
- 1990-04-26 DE DE4013307A patent/DE4013307A1/en not_active Withdrawn
-
1991
- 1991-04-24 PT PT97464A patent/PT97464B/en not_active IP Right Cessation
- 1991-04-24 US US07/690,858 patent/US5185832A/en not_active Expired - Fee Related
- 1991-04-24 AU AU75303/91A patent/AU647468B2/en not_active Ceased
- 1991-04-25 ES ES91106661T patent/ES2082880T3/en not_active Expired - Lifetime
- 1991-04-25 DK DK91106661.1T patent/DK0454107T3/en active
- 1991-04-25 AT AT91106661T patent/ATE131288T1/en active
- 1991-04-25 KR KR1019910006650A patent/KR910018823A/en not_active Application Discontinuation
- 1991-04-25 DE DE59107007T patent/DE59107007D1/en not_active Expired - Fee Related
- 1991-04-25 IE IE138691A patent/IE70746B1/en not_active IP Right Cessation
- 1991-04-25 EP EP91106661A patent/EP0454107B1/en not_active Expired - Lifetime
- 1991-04-25 CA CA002041212A patent/CA2041212A1/en not_active Abandoned
- 1991-04-26 CN CN91102644A patent/CN1056172A/en active Pending
- 1991-04-26 JP JP3096581A patent/JP3044085B2/en not_active Expired - Fee Related
-
1995
- 1995-12-21 GR GR950403662T patent/GR3018523T3/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| US5185832A (en) | 1993-02-09 |
| PT97464A (en) | 1994-02-28 |
| EP0454107B1 (en) | 1995-12-06 |
| IE70746B1 (en) | 1996-12-30 |
| GR3018523T3 (en) | 1996-03-31 |
| JP3044085B2 (en) | 2000-05-22 |
| KR910018823A (en) | 1991-11-30 |
| PT97464B (en) | 1998-11-30 |
| IE911386A1 (en) | 1991-11-06 |
| DK0454107T3 (en) | 1996-04-09 |
| ES2082880T3 (en) | 1996-04-01 |
| AU7530391A (en) | 1991-11-07 |
| JPH04226403A (en) | 1992-08-17 |
| ATE131288T1 (en) | 1995-12-15 |
| AU647468B2 (en) | 1994-03-24 |
| EP0454107A1 (en) | 1991-10-30 |
| DE4013307A1 (en) | 1991-10-31 |
| DE59107007D1 (en) | 1996-01-18 |
| CN1056172A (en) | 1991-11-13 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| FZDE | Discontinued |