CN1783756A - Optical signal transmission system - Google Patents
Optical signal transmission system Download PDFInfo
- Publication number
- CN1783756A CN1783756A CNA2005101156380A CN200510115638A CN1783756A CN 1783756 A CN1783756 A CN 1783756A CN A2005101156380 A CNA2005101156380 A CN A2005101156380A CN 200510115638 A CN200510115638 A CN 200510115638A CN 1783756 A CN1783756 A CN 1783756A
- Authority
- CN
- China
- Prior art keywords
- optical fiber
- light
- transmission system
- signal transmission
- light signal
- 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.)
- Pending
Links
Images
Landscapes
- Optical Couplings Of Light Guides (AREA)
Abstract
A multi-mode optical signal transmission system comprising: an optical fiber which transmits an optical signal; a vertical cavity surface emitting laser diode which is provided for emitting a light beam to an end surface of the optical fiber; and a light receiving element which is provided to an opposite end side to the side of the end surface of the optical fiber and receives the light beam emitted from an end of the optical fiber; wherein the vertical cavity surface emitting laser diode includesa plurality of light emission points,light beams are emitted simultaneously and a divergent angle of the emitted light beam is equal to or smaller than 23 degrees.
Description
The application be this case applicant in the application number of application on July 14th, 2004 be 200410069754.9, denomination of invention divides an application for the application of " light signal transmission system ".
Technical field
The present invention relates to a kind of light signal transmission system, particularly relate to a kind of light signal transmission system that can carry out the above high-speed light transfer of data of 1Gbps (bit per second).
Background technology
In light signal transmission system, in order to prolong vertical cavity surface-emitting laser diode (Vertical Cavity Surface Emitting Laser Diode, VCSEL hereinafter referred to as) though the life-span of light source and output in order also to cover VCSEL when the low current, an example is Japanese Patent Application Publication 2003-152284.This patent application discloses a kind of system, wherein uses a plurality of light sources, and these light source arrangements are in the scope less than the light guide path end face.
In this technology,, can not use rank to get over refractive index type (SI type) plastic fiber (hereinafter being called POF) and make light guide path in order to be not less than the high-speed transfer of 1Gbps with the multimode transmission means.Be used in the perfluorinate optical fiber in the graded index plastic optical fiber (GI-POF), produce loss because in the less relatively optical fiber of diameter, produce the mould noise.Also have, because optical fiber has so little diameter, effectively being coupled from a plurality of VCSEL light sources to the light guide path end face is difficult, and cost uprises.
Summary of the invention
In view of this, need a kind of new light signal transmission system, wherein, light guide path is coupled to long-life VCSEL light source effectively, and can be not less than the high-speed transfer of 1Gbps, and the generation of mould noise simultaneously is inhibited.
Light signal transmission system of the present invention contains: a kind of refraction index profile optical fiber, and wherein the core diameter that the light signal of an end incident is exported from the other end is not less than 200 μ m; A kind of vertical cavity surface-emitting laser diode that is arranged in described optical fiber one end, described vertical cavity surface-emitting laser diode has the end face output beam of a plurality of smooth launch points to optical fiber, and described vertical cavity surface-emitting laser diode is basic identical from the wavelength that the wavelength of the light beam of light launch point output and the loss of optical fiber wherein diminish; Also have a light receiving element that is arranged in the optical fiber other end, described light receiving element receives from the light signal of described fiber end face output.
The following describes the work of light signal transmission system of the present invention.
In light signal transmission system, light signal (light beam) sends from a plurality of smooth launch point of VCSEL, incides the end as the refraction index profile optical fiber of light guide path.
The light signal of incident is exported from the other end through described refraction index profile optical fiber, and light receiving element receives from the light signal of described refraction index profile optical fiber output.
Because in light signal transmission system, use VCSEL with a plurality of smooth launch points, the light output of supposing each light launch point is identical, when the VCESL with a plurality of smooth launch points compares with the VCESL with a light launch point, the heat that each light launch point produces in having the VCESL of a plurality of smooth launch points reduces, so can realize the longer life of VCESL.
Because in this light signal transmission system, the core diameter of refraction index profile optical fiber is set at and is not less than 200 μ m, the loss that is coupled that can prevent in being coupled process axially drift strengthens, and between refraction index profile optical fiber and the VCESL align and refraction index profile optical fiber and light receiving element between align and also be more prone to.
In order to resist axial drift, usually increase the core diameter of optical fiber.Yet when core diameter surpassed 1000 μ m, the needed quantity of material of optical fiber became excessive and cost increases.Therefore the benefit for axial drift can reach capacity.
In described light signal transmission system, VCSEL is from light launch point emission light beam, and the emitted light beams wavelength is identical with the wavelength that the loss of refraction index profile optical fiber wherein diminishes substantially.With such emission, can be not less than the high-speed light transmission of 1Gbps reliably.
" wherein the loss of optical fiber diminish wavelength " refers to wherein the loss of optical fiber and becomes and be no more than 500dB/Km.The loss of optical fiber is preferably and is no more than 300dB/Km, more preferably is no more than the wavelength of 200dB/Km.
In light signal transmission system of the present invention, can be 770nm to 810nm from the wave-length coverage of vertical cavity surface-emitting laser diode emitted light beams.
Below, under the situation of above-mentioned setting, the effect of optical transmission system of the present invention is described.
For example, adopt in the refraction index profile optical fiber of the compound manufacturing that comprises the deuterate methacrylate, to the wave-length coverage of about 810nm, can reduce loss at about 770nm at the polymer composites that constitutes fibre core.Therefore, by in the scope of 770nm to 810nm, reducing loss to the wavelength set of the light beam of launching from VCSEL.
In light signal transmission system of the present invention, described a plurality of smooth launch points can be arranged in the excircle of fibre core at the end face of optical fiber.
Below, the effect of light signal transmission system in the case is described.
Light beam is launched from the light launch point, simultaneously slight scattering.Therefore, in the excircle of the end fibre core by a plurality of smooth launch points being arranged in optical fiber, can receive effectively from light launch point emitted light beams at the end face of described optical fiber.
In light signal transmission system of the present invention, described optical fiber can be the refraction index profile plastic optical fibre, and the light hydrogen content of c h bond can be no more than 60mg/ gram polymer in the fibre core polymer.
Below, the effect of light signal transmission system in the case is described.
Because the refraction index profile optical fiber that synthetic resin is made is as the optical fiber in the light signal transmission system, the optical fiber of described synthetic resin manufacturing has freedom from vibration and resistance to bend(ing), and compares with glass fibre, is easier to lay.
Described optical fiber is formed by refraction index profile optical fiber, and the light hydrogen content of c h bond is set at and is no more than 60mg/ gram polymer in the fibre core polymer.Therefore when using wavelength to be not less than the near-infrared light source of 770nm, the wave-length coverage that produces loss can move to longer wave-length coverage, to reduce the loss of transmission signals light beam.
In light signal transmission system of the present invention, the light hydrogen of c h bond can be used deuterate polymer or halogen polymer manufacturing in the fibre core polymer.
Below, the effect of light signal transmission system in the case is described.
The light hydrogen of c h bond can be realized the effect of the light signal transmission system in this case at low cost with deuterate polymer or halogen polymer manufacturing in the fibre core polymer.
In light signal transmission system of the present invention, described polymer can be poly-(methyl) acrylate compounds of deuterate.
Below, the effect of the light signal transmission system in this case is described.
The mode of making polymer with poly-(methyl) acrylate of deuterate can reduce production cost and material cost.Particularly, combine and to reduce loss by adopting poly-(methyl) acrylate of deuterate to make light beam wavelength that fibre core and VCSEL have 770nm to 810nm scope.
In light signal transmission system of the present invention, described light receiving element can be MSM type photodiode.
Below, the effect of the light signal transmission system in this case is described.
Form by MSM type photodiode by described light receiving element, can the high speed receiving optical signals.
In light signal transmission system of the present invention, the core diameter of described optical fiber can be in the scope of 250 μ m to 900 μ m.
Below, the effect of light signal transmission system in the case is described.
Cost and the balance between the countermeasure of axially drifting about are by realizing in the scope that the core diameter of described refraction index profile optical fiber is arranged on 250 μ m to 900 μ m.
A second aspect of the present invention is a kind of light signal transmission system, described light signal transmission system contains the optical fiber of transmitting optical signal, be arranged on described optical fiber an end, be used for being used to receive light receiving element from the end face emitted light beams of optical fiber to vertical cavity surface-emitting laser (VCSEL) diode of the end face of optical fiber emission light beam and the other end that is located at optical fiber.In this system, described vertical cavity surface-emitting laser diode comprises a plurality of smooth launch points, and wherein light beam is launched simultaneously, and the angle of divergence of outgoing beam is equal to or less than 23 degree.
The running of this system is as follows.
In this system of a second aspect of the present invention, each light launch point of VCSEL diode penetrates a light beam.The light beam of described ejaculation incides on the end face of optical fiber.Penetrating the light beam that comes from the other end of described optical fiber is received by described light receiving element.Because little beam divergence angle promotes optical fiber input, so the angle of divergence of institute's emitted light beams is equal to or less than 23 degree.
In some cases, the described angle of divergence can be equal to or less than 21 degree.
In this system, described optical fiber can be graded index plastic optical fiber (GI-POF).
In this system, described vertical cavity surface-emitting laser can comprise current-limiting layer, and described limiting layer can be by optionally oxidation, and can form the oxidized hole that a diameter is equal to or less than 11 μ m in described limiting layer.
Diameter by described oxidized hole is set to be not more than 11 μ m, the angle of divergence can become be equal to or less than 23 the degree.
As mentioned above, light signal transmission system of the present invention has above-mentioned configuration, thereby can obtain following effect at least.
(1) owing to uses VCSEL to make light source with a plurality of launch points, the light output of supposing each light launch point is identical, VCSEL with a plurality of launch points compares with the VCSEL with a launch point, having the heat that each light launch point produces among the VCSEL of a plurality of launch points can reduce, and can realize the longer life of VCSEL.
(2) because the core diameter of refraction index profile optical fiber is set to such an extent that be not less than 200 μ m, can prevent to be coupled the loss that is coupled of axially drifting about in the process increases, between refraction index profile optical fiber and the VCSEL align and refraction index profile optical fiber and light receiving element between align and also be more prone to, and can prevent to produce the mould noise.When and axial drift in be coupled process little when core diameter is big, be easy to produce the mould noise.Therefore, can suppress the axially influence of drift by increasing core diameter.Can observe the mould noise by the stretching, extension of observing eyelet in S/N ratio or the eye pattern.
Description of drawings
Fig. 1 is the schematic diagram according to the light signal transmission system of one embodiment of the invention.
Fig. 2 is the front view of VCSEL.
Fig. 3 is the sectional view of two fibre core band coating fiber optic cables.
Fig. 4 is the plane graph of the light launch point of VCSEL.
Fig. 5 is the sectional view of light launch point shown in Figure 4.
Fig. 6 is the circuit diagram of the VCSEL shown in Fig. 4.
Embodiment
Explain the preferred embodiments of the invention with reference to the accompanying drawings.
As shown in Figure 1, the light signal transmission system 10 of this embodiment comprises transmitting element 12, receiving element 14 and the fiber optic cable 16 that is coupled with described transmitting element 12 and described receiving element 14.Fiber optic cable describes in detail
In the fiber optic cable 16 of this embodiment, make optical fiber with GI-POF 18.
The GI-POF 18 of the present embodiment is the optical fiber with refraction index profile.As long as GI-POF has refraction index profile and core diameter is not less than 200 μ m, any GI-POF may be used to described optical fiber.From anti-vibration, not flexible, be convenient to lay, the end face processing characteristics, described plastic fiber (GI-POF) with refraction index profile is preferably used in and inner cabling security consideration.When described plastic optical fibre is used for wavelength and is not less than the near-infrared light source of 770nm,, the low-order harmonic of the stretching vibration of the c h bond that constitutes optical fiber causes absorption loss owing to absorbing.Therefore, when in constituting the polymer of core segment, replacing light hydrogen atom in the c h bond with the halogen atom of D atom or fluorine atom and so on (as at WO 93/08488, illustrated among JP-A 58-149003 and the JP-A 10-293125, such as deuterate polymethyl methacrylate (PMMA-d8.d5.d3), the tert-butyl group-d14 polymethyl methacrylate, polymethylacrylic acid fluorine ethyl ester (P3FMA), with poly-hexafluoro isopropyl-fluoro acrylic ester (HFIP2-FA)), can make the wave-length coverage that produces the loss scope elongated to reduce the loss of transmission signals light.As described in the JP-A 8-5848, can use the GI-POF of perfluorinated resin manufacturing.Yet, in the GI-POF that makes with perfluorinated resin, the manufacture of materials characteristic does not have advantage, when comparing with acrylate monomer that has reduced the light hydrogen content in the c h bond or methacrylate monomers, production cost is higher, and meticulous adjusting when making prefabricated blank is for example merged diffusion method and multilayer and is contaminated coating.Therefore use the polymer of acrylate monomer or methacrylate monomers usually, rather than perfluorinated resin.(methyl) acrylate, for example floride-free (methyl) acrylate and fluorine-containing (methyl) acrylate, distyryl compound and vinyl acetate and so on, can exemplify is the polymerization single polymerization monomer of using always.Core segment can be with copolymer or the monomer of above-mentioned material and the mixture manufacturing of homogeneous polymers and/or copolymer of the homogeneous polymers that contains at least two above-mentioned materials.Can use these to contain the material of the composition of (methyl) acrylate as polymerization single polymerization monomer.
Fibre core composition material of the present invention usually by polymerization comprise above-mentioned at least monomer, polymerization initiator, with and the polymerization constituent of the refractive index compound different with described polymerization monomer make.
The following describes the embodiment of the refraction index profile plastic optical fibre that uses as the preferred mode of the present invention, described refraction index profile plastic optical fibre has core segment and coating part.
Described embodiment mainly comprises two types.Yet, the invention is not restricted to following embodiment.
First embodiment is to make the method for plastics light member.Described method comprises: first technical process, and the polymeric compositions material of this technical process polymerization coating part is used to produce the pipe as the coating part; Second technical process, in second technical process, form zone as interior core segment, described zone as core segment forms by the polymeric compositions material in the hollow space median surface of pipe gel polymerisation core segment, has the prefabricated blank that corresponds respectively to described core segment and described coating subregion respectively to produce; And the 3rd technical process that resulting prefabricated blank is processed into the desired style.For example, WO 93/08488 can be incorporated by reference.
Second embodiment is to make the method for plastics optical element.This method comprises first technical process, comprise two layers at pipe described in described first technical process, these two layers are by the polymeric compositions material of rotation polymerization polymerization as outer covering layer, on the inner wall surface of the pipe of the fluorine resin manufacturing such as polyvinylidene fluoride, produce one outside core layer and producing; Second technical process, in second technical process, form zone as core segment, described zone as core segment forms by the polymeric compositions material in the hollow space median surface of pipe gel polymerisation core segment, has respectively corresponding to coating part, outer core segment and the subregional performance of interior fiber core part to produce; With the 3rd technical process that forms resulting performance with desired form.For example, JP-A10-293125 can be incorporated by reference.
In second embodiment, when producing concentric double-deck pipe, described pipe can use the one-step method of the polymer of the polymeric compositions material that merges coextrusion fluororesin and outer core segment to produce, and progressively method that need not be above-mentioned.
Form the polymeric compositions material of described coating part or described outer core segment, except that the initator of deuterate polymethacrylates that is commonly used for polymerization single polymerization monomer and initiated polymerization monomer polymerization, can contain chain-transferring agent etc.
The polymeric compositions material that forms core segment or interior core segment comprises: be different from compound (the refractive index control composition: dopant) of described monomer as the deuterate polymethacrylates of polymerization single polymerization monomer, the initator that causes the polymerization single polymerization monomer polymerization, chain-transferring agent and (time) if desired refractive index usually.
In second embodiment,,, the different adhesion properties reductions that cause with the material of core segment of coating part all alleviated because descending with productivity ratio by core segment outside between coating part and core segment, forming.
In fluorine resin, the hydrophobicity height, and the refringence of coating part and core segment can increase, and fluorine resin is used as the coating part usually in second embodiment.Particularly, usually use polyvinylidene fluoride resin or similar material.
Corresponding to the pipe of coating part, can extrude commercially available fluororesin by fusion and form pipe with required diameter and thickness.
Can be by rotation polymerization composition material in the hollow space of pipe, and on the inwall of the hollow space of the pipe that obtains, form described outside core layer.Similarly structure can be by extruding polymer and the polymeric compositions material production that contains fluororesin jointly.
When using the polymeric compositions material producing third contact of a total solar or lunar eclipse member of this embodiment, can form the light member that slope generates described refraction index profile aspect the described refractive index control constituent concentration by using described refractive index control composition.
On refractive index control constituent concentration, cause the method for slope, for example the method for the interface gel polymerization that in WO 93/08488, WO 03/019252, JP-A 2003-75656 and 2003-149463, illustrates.
The polymeric compositions material that forms coating part and outer core segment and core segment can contain polymerization initiator and chain-transferring agent, and polymerization initiator and chain-transferring agent illustrate in WO 93/08488, WO 03/019252, JP-A 10-293215,2003-75656 and 2003-149463.The polymeric compositions material that forms core segment can contain polymerization initiator, chain-transferring agent and refractive index control composition, and described polymerization initiator, chain-transferring agent and refractive index control composition illustrate in above-mentioned reference paper.
Except the method that in WO 93/08488, WO 03/019252, JP-A 2003-75656 and 2003-149463, illustrates, the technology that illustrates among technique known and Japanese patent application 2002-346250 and the 2002-188181 can also be used for the manufacture method of each technical process.
The core diameter scope of GI-POF 18 is 200 μ m to 1000 μ m.The core diameter scope of GI-POF 18 is preferably in the scope of 250 μ m to 900 μ m, more preferably in the scope of 300 μ m to 800 μ m.
The details of transmission unit
Transmission unit 12 comprises shell 20 and substrate transport 22.
Transmission unit 22 comprises VCSEL 24, electrical signal input unit 26, becomes described electrical signal conversion light signal to drive the circuit (not shown) of VCSEL 24.
Technology that illustrates in JP-A 2003-152284, JP-A 11-121867 or similar techniques can be used as VCSEL 24.
About 780nm of VCSEL 24 emission center wavelength of the present embodiment and the laser beam of the about 3mW of power.As shown in Figure 2, the VCSEL 24 of the present embodiment has four light launch points 28 (arrangement of 2x2 point formation), and described smooth launch point is arranged with the spacing (P) of 50 μ m.Figure 4 and 5 respectively illustrate the general structure of the VCSEL 24 of the present embodiment.One of light launch point has the structure that diameter is the cylindrical mesa of 27 μ m.This structure comprises that a last metal electrode that is used to provide drive current 62, one transmit and be directed on wherein the last contact layer 64, one DRB mirror layer 66, a current-limiting part 68 and an active layer 72 from the electric current of last metal electrode 62 through emitted light beams, and described current-limiting part 68 is from the part oxidation selectively at the about 9 μ m of diameter to inside of table top side surface.Core at the mesa structure of limiter 68 inside is called oxidized hole 70.Fig. 6 is the circuit diagram of VCSEL 24 shown in Figure 4.Four launch points are driven simultaneously by identical drive signal.Reference numeral 74 is represented microcomputer in Fig. 6, and Reference numeral 76 representatives produce the Drive and Control Circuit of drive signal, and Reference numeral 78 is represented launch point.
The non-oxide part of the core of demand limiter 68 or the diameter in oxidized hole 70 are equal to or less than 11 μ m.Preferably, the diameter in this oxidized hole 70 is in the scope of 8 μ m to 11 μ m.In described non-oxide part, light beam is with the angle of divergence open-angle emission in other words of about 21 degree.The described angle of divergence is defined as the 1/e that its power is peak value
2The angle at place.Usually, the angle of divergence is more little, and is just easy more to the incident of optical fiber.On the other hand, when according to this point, oxidized Kong Yuexiao, the life-span of fiber is also just short more.Rational answer to this contradiction is that the angle of divergence is set to such an extent that be not more than 23 degree, is not more than 21 degree better, perhaps is not more than 19 degree better.
At this, when using different optical fiber, for example have the optical fiber of much bigger diameter, the light launch point can take advantage of four dot matrix shapes to arrange by four, and is disclosed as JP-A 2003-152284.As commutable scheme, the light launch point can concentric arrangement or with other arrayed.No matter how arrange, the spacing between two adjacent launch points should be set in 40 μ m to 50 mu m ranges, with the identical light beam of light beam that obtains sending with the single launch point of VCSEL 24 substantially qualitatively.
Although the VCSEL of metal can encapsulation shown in Figure 1 the invention is not restricted to VCSEL shown in Figure 1.
As shown in Figure 1, optical fiber 16 usefulness connector (not shown) are coupled to shell 20.
At this, in being coupled between GI-POF18 and VCSEL 24, can use butt joint to be coupled, wherein the output face of VCSEL 24 is directly connected on the GI-POF18.As alternative scheme, can be parallel by using non-spherical lens or globe lens that light is guided into, be directed in the light guide path, perhaps described light path is assembled to be coupled GI-POF18 and VCSEL 24.
As shown in Figure 2, in the excircle (illustrating) of the end face of GI-POF18, arrange a plurality of smooth launch points 28 by chain-dotted line.
As shown in Figure 1, in this embodiment, between the end face of VCSEL 24 and GI-POF18, be provided with globe lens 30.
Focus on the incident end face of GI-POF18 with identical multiplication factor by using globe lens 30 from the light of VCSEL 24 emissions.
Receiving element describes in detail
Receiving element 14 comprises shell 32 and receives substrate 34.
Receive the circuit (not shown) that substrate 34 comprises light receiving element 36, signal of telecommunication output unit 38 and light signal converted to the signal of telecommunication.
The photodiode (PD) of high-speed silicon PIN photodiode or gallium arsenide PIN photodiode and MSM (metal-semiconductor-metal) photodiode and so on can be used as light receiving element 36.Also can use other light receiving element.
In this embodiment, the optical receiving surface diameter is that the gallium arsenide PIN photodiode of 100 μ m is as light receiving element 36.
Optical fiber 16 usefulness connector (not shown) are connected to shell 32.
At this, in being coupled between GI-POF18 and light receiving element 26, can use butt joint to be coupled, wherein the light of GI-POF18 output directly is coupled on the light receiving element 36.As alternative scheme, can be parallel by using non-spherical lens or globe lens that light is guided into, to be directed in the light guide path, perhaps described light path is assembled to be coupled GI-POF18 and light receiving element 36.
In this embodiment, non-spherical lens (convex lens) 40 is arranged between the end face and receiving element 36 of GI-POF18, to form reduce in scale is 3: 1 the mode that is coupled, and is incident on the optical receiving surface of light receiving element 36 by non-globe lens (convex lens) 40 focusing from the light beam that GI-POF18 launches.
Can carry out high-speed cruising and have photodiode, for example have the MSM photodiode of the optical receiving surface diameter of 250 μ m, also can be used in the present embodiment than the major diameter optical receiving surface.In the case, can reduce the reduce in scale of non-spherical lens 40.The core diameter that depends on GI-POF has the low-cost lens that can use identical multiplication factor or can be without the achieve a butt joint advantage of coupling of lens.
Operation
Below, the operation of the light signal transmission system 10 of this embodiment is described.
For example the light signal transmission system 10 of the present embodiment is preferred under the situation of the vision signal with bulk information, and described vision signal is transferred to display from computer.
As shown in Figure 1, the vision signal output unit (not shown) of computer is connected to the electrical signal input unit 26 of transmission unit 12 through a cable, and the vision signal input unit (not shown) of display is connected to the signal of telecommunication output unit 38 of receiving element 14 through cable.
In transmission unit 12, electrical signal conversion becomes light signal, and with each the light launch point 28 output light signal (light beam) from VCSE L24, and light signal is transferred to described receiving element 14 through globe lens 30 and fiber optic cable 16 (GI-POF18).
In receiving element 14, light signal is input to light receiving element 36 through non-spherical lens (convex lens) 40, and light signal converts the signal of telecommunication to output to described display.
In the light signal transmission system 10 of the present embodiment, because VCSEL 24 comprises a plurality of smooth launch points 28, to compare with the situation of the VCSEL that a light launch point 28 is arranged, the heat that each light launch point produces can reduce, and can prolong the life-span of VCSE L24.
The core diameter of GI-POF18 is set at and is not less than 200 μ m, and the light launch point 28 of VCSEL 24 is arranged in the excircle of end face of GI-POF18, thereby can prevent that in being coupled process axially the loss that is coupled of drift becomes big.In addition, between GI-POF18 and the VCSEL 24 align and GI-POF18 and light receiving element 36 between align can also transfiguration easy.
In fiber optic cable 16, because the GI-POF18 that makes with synthetic resin is as optical fiber, the optical fiber of synthetic resin manufacturing has freedom from vibration and resistance to bend(ing), thereby compares with glass fibre, and the laying of optical fiber is convenient to carry out.
GI-POF18 constitute the polymeric compositions material compound manufacturing that contains the deuterate polymethacrylates of GI-POF18 fibre core, and the wavelength set of the light beam of VCSEL 24 is in the scope of 770nm to 810nm as optical fiber.Therefore reduce loss and can be not less than the high-speed light transmission of 1Gpbs reliably.
Embodiment
In order to confirm effect of the present invention, mode with test has been set up the embodiment that has used light signal transmission system of the present invention, with the light signal transmission system embodiment of contrast, and to described embodiment and reference examples in loss, bandwidth, be coupled and carried out mutual comparison aspect efficient and the light source life.
The test macro explanation
Embodiment 1
The centre wavelength that VCSEL uses is the optical fiber of 780nm.
The quantity of light launch point is four (arrangements of 2x2 dot matrix) and the light launch point spacing arrangement with 50 μ m.
Make GI-POF with following composition material.
Describe make raw material manufacturing GI-POF with MMA-d8 below.
Adopt KF-850 (Kureha Chemical Industry Co., the product of Ltd.) extruding to make the difluoroethylene pitch tube, the internal diameter of this pipe is 22mm, and length is 600mm, and also make with KF-850 the bottom of pipeline.Scheduled volume deuterated methyl methacrylate (MMA-d8) is injected in the described difluoroethylene pitch tube.In described deuterated methyl methacrylate, remove quinhydrones mono-methyl, and moisture content is removed to is no more than 80ppm as polymerization inhibitor.
Wherein the ratio in 0.5 quality % adds the two isobutyrates (MAIB) of azo as the polymerization induced agent in monomer solution, and in monomer solution, add the n-lauryl mercaptan as chain-transferring agent, such mixed solution is annotated in the difluoroethylene pitch tube in the ratio of 0.4 quality %.
It is 70 ℃ hot bath that the polymerization pipe that has injected monomer mixture solution is placed on temperature, carries out two hours prepolymerization in the vibration polymerization pipe.
Under 65 ℃, polymerization pipe is remained on level (short transverse of cylinder becomes level) one hour, under 70 ℃, polymerization pipe was remained on level three hours then.In with the rotational speed of 3000rmp, heat and the described polymerization pipe of polymerization then.Carry out heat treatment in 24 hours to obtain the pipe that above-mentioned polymer is made at 90 degrees centigrade.
As the monomer (MMA-d8) of the raw material of core segment with as dopant and ratio monomer solution is that the diphenyl sulfide of 7 quality % mixes.Similarly, in deuterated methyl methacrylate, remove quinhydrones mono-methyl, and moisture content is removed to is no more than 80ppm as polymerization inhibitor.
When the tetrafluoroethene film filter that with precision is 0.2 μ m filters described mixed solution, filtrate is directly injected the hollow space of made pipe.
Ratio in 0.016 quality % in monomer mixture solution adds 1,1-di-tert-butyl peroxide (PBD) is as polymerization initiator, and the ratio in 0.27 quality % adds the n-lauryl mercaptan as chain-transferring agent (the chain transfer ratio in this system is 0.8) in monomer solution.
The pipe that has injected mixed solution inserts the glass tube of internal diameter greater than described pipe external diameter 9%, and stands upright in the polymerization pipe of pressurization.
Then, after in the polymerization pipe of pressurization, replacing, be pressurized to the highest 0.005MPa in the polymerization pipe of pressurization, and the polymerization pipe that heats described pressurization is to carry out polymerization 48 hours 100 ℃ of temperature with nitrogen.
When keeping pressurized state, 120 ℃ of heated polymerizable and heat treatments of carrying out 24 hours.Obtain prefabricated blank by slow cooling then.
Do not have because the bubble that volume compression causes is sneaked in the resulting prefabricated blank finishing polymerization.
By extending the plastic fiber element line that the about 300 μ m of core diameter are made in the wire drawing of carrying out prefabricated blank 230 ℃ of heat.In this drawing process, do not observe bubble in the finished product and produce.
As shown in Figure 3, element line 48 applies with low density polyethylene (LDPE) (LDPE) at 120 ℃ by using coating machine, and described coating machine comprises the quadrature crosshead die to obtain the band coating optical fiber rope that external diameter is 1.2mm, and wherein first coating 50 directly contacts with heart yearn.
Two band coating optical fiber ropes obtain twin-core fiber cable at 130 ℃ with polyvinyl chloride (PVC) coating by using coating machine, described coating machine comprise be used in first coating 50 in the different mould of mould, the short diameter of its mesotheca layer 52 is 3.2mm, and the long diameter of sheath layer 52 is 6.2mm.Thereby obtain two doped core optical fiber cables, wherein the part to hollow vertically adds aramid fiber as tension member.
Reference examples 1
Produce GI-POF with first embodiment the samely, exception be that what to be used for the fibre core composition material is the common polymethyl methacrylate of non-deuterate.
Reference examples 2
Use GI-POF (trade name: " Lucina ", Asahi Glass Co., Ltd. manufacturing).Core diameter is 120 μ m, and the fibre core composition material uses perfluorinated resin.Use the light source that is applicable to the 850nm wavelength of perfluorinated resin and a light launch point is arranged in addition.Other condition is identical with first embodiment.
Reference examples 3
Use the SI-POF (trade name: SK-10, Mitsubishi Rayon Co., Ltd. makes) of core diameter 250 μ m to replace GI-POF.Other condition is identical with first embodiment.
Reference examples 4
Use wavelength 780nm and have the VCSEL light source of a light launch point.Other condition is identical with first embodiment.
Test method
By the following method an optical fiber of two doped core optical fiber cables is tested.
The axis of described optical fiber aligns with VCSEL, to be coupled on the light emitting surface of VCSEL with identical multiplication factor by the use globe lens.At this, coupling efficiency is 0.8dB.
Loss is measured and is undertaken by the method for optical source wavelength being cut down measurement.
Fiber bandwidth is undertaken by the length that adopts time domain approach to measure 50m.
Light source life measuring condition: under 2mW output and 60 ℃ of temperature conditions, carry out accelerated test.
Be coupled efficient (in the VCSEL emission side): use the identical multiplication factor of globe lens system, to the mobile fibre axis 80 μ m of XY direction (perpendicular to the direction of axis), and VCSEL and optical fiber are coupled mutually to measure with on purpose.
The mould noise is estimated by near the noise level the eyelet in the 3Gbps place eye pattern.
Table 1
| Fiber | Loss | ||||
| Type | Core material | Core diameter | Per 50 meters length bandwidth | ||
| Embodiment 1 | GI-POF | The deuterate acrylic resin | 300μm | 5.6GHz | 100dB/Km |
| Reference examples 1 | GI-POF | Common acrylic resin | 300μm | 3.2GHz | 800dB/Km |
| Reference examples 2 | GI-POF | Perfluorinated resin | 120μm | 5.2GHz | 80dB/Km |
| Reference examples 3 | SI-POF | Common acrylic resin | 250μm | ≤200GHz | 800dB/Km |
| Reference examples 4 | GI-POF | The deuterate acrylic resin | 300μm | 5.6GHz | 100dB/Km |
| Optical source wavelength | Light launch point quantity | Light source life | Be coupled efficient | The mould noise level | |
| Embodiment 1 | 780nm | 4 | Be not less than 1 * 10 5Hour | 2.0dB | Little |
| Reference examples 1 | 780nm | 4 | Be not less than 1 * 10 5Hour | 2.0dB | -(can not carry out the 3Gbps transmission) |
| Reference examples 2 | 850nm | 1 | Be not less than 1 * 10 5Hour | 5.0dB | Greatly |
| Reference examples 3 | 780nm | 4 | Be not less than 1 * 10 5Hour | 2.3dB | -(can not carry out the 3Gbps transmission) |
| Reference examples 4 | 780nm | 1 | Be not higher than 1 * 10 4Hour | 2.0dB | Little |
In embodiment 1, reference examples 1 and reference examples 3,, be no less than 1 * 10 when having confirmed 2mW output by 60 ℃ accelerated test because use VCSEL light source with a plurality of smooth launch points
5Hour useful life.
Have in the reference examples 4 of a light launch point at the VCSEL light source, have to be no more than 1 * 10
4Hour life-span.
The bandwidth of 50 meters length of optical fiber of deuterate acrylic resin manufacturing is 5.6GHz.Test is found to be enough to be used in high-speed transfer with the optical fiber of deuterate acrylic resin manufacturing.
Claims (8)
1. light signal transmission system, it contains:
The optical fiber of transmitting optical signal;
Be located at described optical fiber an end, be used for vertical cavity surface-emitting laser diode to the end face of described optical fiber emission light beam; And
Be located at the distolateral relatively light receiving element that is used to receive from an end emitted light beams of described optical fiber of the described end face side of described optical fiber,
Wherein, described vertical cavity surface-emitting laser diode comprises a plurality of smooth launch points, and wherein light beam is launched simultaneously, and the angle of divergence of outgoing beam is equal to or less than 23 degree.
2. light signal transmission system as claimed in claim 1 is characterized in that: the angle of divergence of described outgoing beam is equal to or less than 21 degree.
3. light signal transmission system as claimed in claim 1 or 2 is characterized in that: described optical fiber is graded index plastic optical fiber.
4. light signal transmission system as claimed in claim 1 or 2, it is characterized in that: described vertical cavity surface-emitting laser diode comprises a current-limiting layer, the optionally oxidation of described limiting layer quilt, and in described limiting layer, form the oxidized hole that a diameter is equal to or less than 11 μ m.
5. light signal transmission system as claimed in claim 4 is characterized in that: the diameter in described oxidized hole is in the scope of 8 μ m to 11 μ m.
6. light signal transmission system as claimed in claim 1 is characterized in that: the core diameter of described optical fiber is in the scope of 250 μ m to 900 μ m.
7. light signal transmission system as claimed in claim 1 is characterized in that: the wavelength of described light beam is in the scope of 770nm to 810nm.
8. light signal transmission system as claimed in claim 1 is characterized in that: the spacing between the described smooth launch point is in the scope of 40 μ m to 50 μ m.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2003274332 | 2003-07-14 | ||
| JP2003274332 | 2003-07-14 | ||
| JP2004177296 | 2004-06-15 |
Related Parent Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB2004100697549A Division CN1261778C (en) | 2003-07-14 | 2004-07-14 | Optical signal transmission system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN1783756A true CN1783756A (en) | 2006-06-07 |
Family
ID=36773567
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNA2005101156380A Pending CN1783756A (en) | 2003-07-14 | 2004-07-14 | Optical signal transmission system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN1783756A (en) |
-
2004
- 2004-07-14 CN CNA2005101156380A patent/CN1783756A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN1261778C (en) | Optical signal transmission system | |
| CN1246711C (en) | Plastic optical fibre | |
| CN1101000C (en) | Distributed refractive index optical fiber and method for mfg. same | |
| JP6460321B2 (en) | Multi-core optical fiber and multi-core optical fiber cable | |
| CN1136352A (en) | Wide band optical fiber, optical fiber core wire and optical fiber cord | |
| CN1119676C (en) | Refractive index profile type optical fiber | |
| CN1771443A (en) | Method and apparatus for manufacturing plastic optical transmission medium | |
| US6606441B2 (en) | Plastic optical fiber, optical fiber cable and optical transmission device | |
| CN1783756A (en) | Optical signal transmission system | |
| JP2008511011A (en) | Optical coupling method and optical transceiver | |
| CN1828347A (en) | Optical fiber and optical interconnection system | |
| CN1256759A (en) | Method and apparatus for reducing coherence of light, method and apparatus for illumination, and fiber bundle | |
| JP5459070B2 (en) | Plastic optical fiber and plastic optical fiber cord | |
| JP5095328B2 (en) | Optical transmission module | |
| JP2007047371A (en) | Method of manufacturing plastic optical fiber cable | |
| CN1823285A (en) | Plastic optical fibers and processes for producing them | |
| JP4323121B2 (en) | Plastic rod lens, lens array, and image sensor | |
| CN113267845A (en) | Plastic optical fiber, plastic optical fiber cable with connector, optical communication system, and plastic optical fiber sensor | |
| JP5047816B2 (en) | Plastic optical fiber tape | |
| JP2007256674A (en) | Optical coupling element, optical connector, and optical transmission system | |
| JP2006064766A (en) | Plastic optical fiber, code, and optical communication system | |
| JP2005517204A (en) | Graded index polymer optical fiber and manufacturing method thereof | |
| JP2006064767A (en) | Plastic optical fiber cord | |
| KR20080088614A (en) | Method for manufacturing multi-layer light transmission medium and plastic optical fiber | |
| JP2006154590A (en) | Method for manufacturing graded-index optical member, polymerizable composition for formation of optical member, and optical member |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C02 | Deemed withdrawal of patent application after publication (patent law 2001) | ||
| WD01 | Invention patent application deemed withdrawn after publication |