WO2004019099A1 - 光通信システム - Google Patents
光通信システム Download PDFInfo
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- WO2004019099A1 WO2004019099A1 PCT/JP2003/010543 JP0310543W WO2004019099A1 WO 2004019099 A1 WO2004019099 A1 WO 2004019099A1 JP 0310543 W JP0310543 W JP 0310543W WO 2004019099 A1 WO2004019099 A1 WO 2004019099A1
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- optical fiber
- optical
- face
- diameter
- light
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- 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
- G02B6/42—Coupling light guides with opto-electronic elements
- G02B6/4201—Packages, e.g. shape, construction, internal or external details
- G02B6/4202—Packages, e.g. shape, construction, internal or external details for coupling an active element with fibres without intermediate optical elements, e.g. fibres with plane ends, fibres with shaped ends, bundles
Definitions
- the present invention relates to an optical communication system capable of transmitting and receiving an optical signal using an optical fiber, and more particularly to home communication, communication between electronic devices, and LAN (local 'area') using a plastic optical fiber as a transmission medium.
- the present invention relates to an optical communication system applicable to a network such as a local area network.
- An optical communication system using an optical fiber includes a transmission system at one end of a signal transmission path using an optical fiber and a reception system at the other end.
- the transmission system is provided with a light source (light emitting element) such as a light emitting diode / semiconductor laser, and controls the light emitting source to make the signal light emitted emit light enter the optical fiber.
- the receiving system includes a light receiving element such as a photo diode, and the light receiving element receives the signal light emitted from the optical fiber and converts the signal light into an electric signal.
- the performance of such an optical communication system greatly depends on the transmission efficiency of signal light.
- the transmission efficiency is mainly determined by the transmission efficiency of the optical fiber itself, the coupling efficiency from light emission to the optical fiber, and the coupling efficiency from the optical fiber to the light receiving element.
- Reception systems in conventional optical communication systems can be broadly classified into those that directly receive light emitted from an optical fiber with a light receiving element and those that use a lens or other optical system placed between the optical fiber and the light receiving element. There are two types of light that is collected and received.
- Such an optical coupling method between an optical fiber and a light receiving element is widely used for a quartz fiber having a core diameter of a micrometer order.
- a problem arises in the case of a plastic optical fiber having a core diameter of the order of millimeter.
- Plastic optical fiber is an optical fiber that has recently attracted attention in home networks, etc.
- Plastic optical fiber has a large fiber diameter of 0.5 to 2 mm, making it easy to connect. The coupling efficiency of the is there.
- the light receiving diameter of the light receiving element used for optical fiber communication is several hundreds / zm to 100 m.Therefore, there is no problem if the optical fiber has a small core diameter.For example, in the case of a plastic optical fiber having a diameter of l mm, This is because it is difficult to focus light to a size smaller than the size of the light source even if a lens or the like is used. In particular, the higher the transmission speed, the smaller the light receiving diameter is required due to the capacity, so that the coupling efficiency, that is, the receiving efficiency decreases.
- an optical communication system having a coupling structure of an optical fiber and a light receiving element as shown in FIG. 25 is known.
- a light guide 101 having a light guide path 102 surrounded by a highly reflecting and reflecting surface 103 is provided between an optical fiber 104 and a light receiving element 105.
- the signal light emitted from the optical fiber 104 is guided to the light receiving element 105 by the light guide 101.
- high-efficiency optical coupling between the optical fiber 104 and the light-receiving element 105 is achieved, and even if the light is emitted from an optical fiber having a large core diameter, such as a plastic optical fiber, the light having a small diameter can be obtained.
- the light is efficiently condensed on a small photodiode (see, for example, FIG. 1 and FIG. 3 in paragraph No. 008 of JP-A-10-221573).
- an object of the present invention is to provide an optical communication system capable of efficiently coupling a large-diameter optical fiber such as a plastic optical fiber and a small-diameter light receiving element with a simple configuration and efficiently.
- An optical communication system includes an optical fiber having a spherical end face at least on one end side, a numerical aperture of radiation emitted from the spherical end face being 0.35 or less, and a light receiving element.
- An optical communication module for receiving light emitted from the spherical end surface of the optical fiber.
- the one end of the optical fiber is connected to the optical communication module.
- the light receiving surface of the light receiving element When inserted at a predetermined point in the fiber, the light receiving surface of the light receiving element is located at a distance d from the vertex of the spherical end face of the optical fiber, the diameter of the optical fiber is D, and the radius of curvature R of the spherical end face is r. * D, If the refractive index of the core of the optical fiber is 11, and the refractive index of the substance existing between the spherical end face of the optical fiber and the light receiving element is n1, the distance d is
- the diameter of the light receiving element is less than or equal to D, it is within the range of 0 and d ⁇ r * D / (n-n1),
- the diameter of the light receiving element is larger than D, it is in the range of D d ⁇ r * D / (n-n 1).
- the “diameter of the optical fiber” is the core diameter.
- the diameter of the optical fiber is almost equal to the diameter of the cladding because the cladding has only 2% of the total diameter.
- the receiving coupling efficiency is up to twice as high as when the end face of the optical fiber is flat. It can be increased to the above.
- Processing the end surface of the fiber into a spherical shape can be considered to be the same structure as attaching a plano-convex lens with a convex surface in the direction in which light from the fiber exits to a flat end surface.
- r * DZ (nn 1) or RZ (nn 1) is the focal length f of a plano-convex lens with a radius of curvature of R and a refractive index of n in a space filled with a substance with a refractive index of n. is there.
- the near-field pattern can be regarded as a uniform intensity surface light source.
- the orientation distribution of light emitted from each point obtained by subdividing the uniform intensity surface light source is a Gaussian distribution.
- the simulation results shown in Figs. 3A-3C show that the refractive index of the plano-convex lens is 1. This is almost the same as the focal length f in air when 5 is set.
- the numerical aperture (NA) of the light emitted from the optical fiber is as small as 0.35 or less
- the light receiving surface of the light receiving element is placed within the focal length ⁇ ⁇ .
- the coupling efficiency is the same as that of an optical fiber with a flat end face until the distance d exceeds D, based on the results of various experiments performed by the inventor.
- the distance d was set to be larger than D because it was found that the force could not be obtained.
- the radiated light emitted from one end face of the optical fiber is incident on the light receiving element before being condensed by the plano-convex lens effect and spread again, so that the light incident on the light receiving element is smaller than when the end face of the optical fiber is flat.
- the coupling efficiency is improved.
- a light guide as in the conventional technology is not used, the manufacture of the optical communication module is correspondingly easy.
- the optical fiber whose outgoing light has an NA of 0.35 mainly has a transmission rate of 200 to 62 2
- the communication module may include, in addition to the light receiving element, a receiving optical system that guides light emitted from the spherical end surface of the optical fiber to the light receiving element.
- the position is set at a distance d from the spherical end face of the optical fiber according to the size of the receiving optical system as follows. In other words, the distance d from the spherical end face of the optical fiber to the center position of the receiving optical system is equal to the receiving optical system.
- the receiving optical system for example, a receiving optical system formed by a member that refracts light, such as a prism and a lens formed of a substance having a different refractive index from air, and a member that reflects light, such as a mirror, is used. is there. Even when a transparent mold member having a refractive index different from that of air is formed on the light receiving element, the molded member is treated as a receiving optical system in the present application.
- the “center position of the receiving optical system” refers to the incident side principal point of the principal ray from the optical fiber to the receiving optical system.
- the “size of the receiving optical system” is the diameter of a portion that optically condenses light in the case of a circular shape (for example, a condenser lens), and is optically light in the case of a non-circular shape (for example, a prism). Is a representative dimension of the condensing part.
- the distance d is preferably
- the diameter of the light receiving element is less than or equal to D, the diameter is preferably in the range of 0 ⁇ d ⁇ 2D.
- the diameter of the light receiving element is larger than D, the diameter is preferably in the range of D d 2D.
- the present invention is more effective when the diameter of the light receiving element (the size of the receiving optical system when the receiving optical system is provided) is not more than the diameter D of the optical fiber. Coupling compared to an optical fiber whose end face is flat compared to a case where the diameter of the light receiving element (the size of the receiving optical system when a receiving optical system is provided) is larger than the diameter D of the optical fiber This is because the effect of improving the efficiency is remarkable.
- An optical communication system includes an optical fiber having a spherical end surface on at least one end side, and a numerical aperture of radiated light emitted from the spherical end surface being 0.4 to 0.6.
- An optical communication module having a light receiving element and receiving light emitted from the spherical end surface of the optical fiber; And the one end side of the optical fiber is the light
- the light-receiving element is inserted into a predetermined location in the communication module, the light-receiving element is located at a distance d from the vertex of the spherical end surface of the optical fiber, and when the diameter of the optical fiber is D, the distance d is:
- the diameter of the light receiving element is D or less, it is within the range of 0 d
- the diameter of the light receiving element is larger than D, it is in the range of 0.5D ⁇ d ⁇ 2D.
- the communication module may include, in addition to the light receiving element, a receiving optical system that guides light emitted from the spherical end surface of the optical fiber to the light receiving element.
- a receiving optical system that guides light emitted from the spherical end surface of the optical fiber to the light receiving element.
- the center position of the receiving optical system is located at a distance d from the spherical end surface of the optical fiber according to the size of the receiving optical system as follows. Become. That is, the distance d from the spherical end surface of the optical fiber to the center position of the receiving optical system is equal to the receiving optical system.
- the size of the receiving optical system is less than D, it is within the range of 0 ⁇ d ⁇ 2D, and when the size of the receiving optical system is larger than D, it is within the range of 0.5D ⁇ d ⁇ 2D. I will be placed myself.
- the receiving coupling efficiency is 1. It can be increased up to about 7 times.
- the definitions of “the center position of the receiving optical system” and “the size of the receiving optical system” are as described above.
- the distance d is determined from various simulation results performed by the inventor.
- the diameter of the light-receiving element is D or less, it is 0 and d ⁇ l.
- the diameter of the light receiving element is larger than D, it is preferable that the diameter be within the range of D ⁇ d ⁇ l.5D.
- the diameter of the light receiving element (the size of the receiving optical system when the receiving optical system is provided) is the optical fiber.
- the diameter of the bus should be less than D.
- the diameter of the light receiving element (or the size of the receiving optical system if a receiving optical system is provided) is larger than the diameter D of the optical fiber, compared to an optical fiber with a flat end face. This is because the effect of improving the coupling efficiency is remarkable. Therefore, by using the present invention, a small receiving optical system that can easily collect light on a small light receiving element can be arranged. In this case, the present invention can exert more effects in single-core two-way communication.
- each of the above-described optical communication modules further includes at least a light-emitting element among a light-emitting element and a transmission optical system, and communicates with the other optical communication module via the optical fiber in a single-core bidirectional communication system.
- Light can be transmitted and received. Since the light receiving element and the receiving optical system can be made smaller, it is effective from the viewpoint of being arranged in parallel with the transmitting system.
- the general fiber diameter is 0.5 to 2 mm, but from the viewpoint of ease of use, that is, ease of connection and suppression of mode dispersion, 1 mm Those with a fino diameter are commonly used.
- the transmission rate of high-speed communication generally used for plastic optical fibers is 10 O Mb ps to 62 M bps, and the photodiode diameter suitable for the transmission rate (hereinafter also referred to as PD diameter) ) Is less than 0.5 mm, more specifically 0.3 to 0.5 mm.
- an optical fiber having a diameter D of l mm and a small-sized photodiode having a diameter of 0.5 mm or less (for example, 0.3 mm to 0.5 mm) capable of high-speed operation. are used in combination.
- Such a combination of the dimensions of the optical fiber and the light receiving element is effective because the application of the present invention can greatly increase the reception efficiency as compared with the flat end face fiber.
- the size of the receiving optical system should be less than 0.5 mm for the same reason as just described. preferable.
- FIG. 1 is a diagram schematically showing a configuration of an optical communication system according to an embodiment of the present invention. It is.
- FIG. 2 is a diagram schematically showing a configuration of an optical communication system according to one embodiment of the present invention.
- 3A, 3B, and 3C are diagrams illustrating the principle of the present invention.
- Fig. 4 is a graph showing the effect of the present invention.
- the diameter of the light-receiving element is 0.5D
- the output NA of the fiber is 0.35
- the reception coupling efficiency when a spherical end face fiber is used is shown when the flat end face fiber is used. It is a graph compared with.
- Fig. 5 is a graph showing the effect of the present invention.
- the diameter of the light-receiving element is D
- the NA of the fiber output is 0.35
- the reception coupling efficiency when using a spherical end face fiber is shown when the flat end face fiber is used. It is a graph compared with.
- Fig. 6 is a graph showing the effect of the present invention.
- the diameter of the light-receiving element is 1.5D
- the fiber output NA is 0.35
- the reception coupling efficiency when using a spherical end face fiber is shown when the flat end face fiber is used. It is a graph compared with.
- Fig. 7 is a graph showing the effect of the present invention.
- the diameter of the light receiving element is 0.5D
- the fiber emission NA is 0.5
- the reception coupling efficiency when using a spherical end face fiber is shown when the flat end face fiber is used. It is a graph compared with.
- Fig. 8 is a graph showing the effect of the present invention.When the light receiving element diameter is D and the fiber emission NA is 0.5, the receiving coupling efficiency when using a spherical end face fiber is compared with that when using a flat end face fiber. It is the graph which did.
- Fig. 9 is a graph showing the effect of the present invention.
- the diameter of the light receiving element is 1.5D
- the fiber output NA is 0.5
- the reception coupling efficiency when using a spherical end face fiber is obtained when a flat end face fiber is used. It is a graph compared with.
- 7 is a table summarizing the comparison results of the reception coupling efficiency shown in the graph of FIG.
- Fig. 16 is a graph showing the effect of the present invention.
- the diameter of the light receiving element is 0.5D and the NA of the fiber output is 0.35
- the reception coupling efficiency when a spherical end face fiber is used is calculated using a flat end face fiber. It is a graph compared with when it was.
- FIG. 17 is a graph showing the effect of the present invention.
- the diameter of the light receiving element is 0.5D and the fiber emission NA is 0.5
- the reception coupling efficiency when a spherical end face fiber is used and the flat end face fiber is used. It is a graph compared with when it was.
- FIG. 18 is a graph showing the effect of the present invention, and is a graph showing the PD diameter dependence of the reception coupling efficiency.
- FIG. 19 is a rough graph showing the effect of the present invention, and shows a comparison between a measured value of the reception coupling efficiency and a value obtained by simulation.
- FIG. 20 is a diagram schematically illustrating a configuration of an optical communication system of a single-core bidirectional communication system according to an embodiment of the present invention.
- FIG. 21 is an enlarged schematic view of a part (near an optical fiber end face) of the optical communication system of FIG.
- FIG. 22 is an explanatory diagram showing the relationship between the dimension and position of the optical system in the optical communication system of the single-core two-way communication system and the coupling between the optical fiber end face of the transmitted Z reception light and the Z reception optical system. It is.
- FIG. 4 is an explanatory diagram showing a relationship between a position and coupling between an optical fiber end face of a transmission Z reception light and a reception optical system.
- FIG. 24 is an explanatory diagram showing the relationship between the size and position of the optical system in the optical communication system of the single-core two-way communication system, and the coupling between the end face of the optical fiber and the receiving optical system of the Z-transmitted received light. is there.
- FIG. 25 is an explanatory diagram of a conventional technique.
- FIG. 26 is a diagram for explaining a problem of the conventional technique shown in FIG. BEST MODE FOR CARRYING OUT THE INVENTION
- FIG. 1 schematically shows an example of an optical communication system for performing one-way communication as an embodiment of the optical communication system of the present invention.
- the optical communication system includes an optical fiber 1 and a pair of optical communication modules 2A and 2B for transmitting and receiving signal light via the optical fiber 1.
- the optical communication module 2B includes a light emitting element 22 composed of a semiconductor laser device (LD) or a light emitting diode (LED) and functions as a transmission module, while the optical communication module 2A includes a photodiode (PD). It has a light receiving element 21 and functions as a receiving module.
- LD semiconductor laser device
- LED light emitting diode
- PD photodiode
- the optical fiber 1 is a plastic optical fiber whose core is made of PMMA (refractive index: approximately 1.5), and has spherical end surfaces 11 each having a radius of curvature R at both end surfaces. However, the spherical end surface 11 may be the only end surface on the receiving side.
- the optical fiber 1 may be made of a plastic material other than PMMA.
- the spherical end face 11 of the optical fiber can be made by melting or polishing.
- the light receiving surface of the light receiving element 21 is at a distance d from the vertex of the spherical end surface 11 of the optical fiber 1. It is just away.
- the distance d is determined by the numerical aperture (hereinafter also referred to as “emission NA”) of the radiated light emitted from the spherical end face 11 of the optical fiber 1 and the light receiving element.
- NA the numerical aperture
- the value is set according to the diameter of the photodiode 21 (hereinafter, also referred to as “PD diameter”).
- the distance d is
- D is the diameter (core diameter) of the optical fiber 1
- r * D is the radius of curvature R of the spherical end face 11 using D
- n is the refractive index of the core of the optical fiber 1
- n 1 is the refractive index of a substance existing between the spherical end face 11 of the optical fiber 1 and the light receiving element 21.
- the substance existing between the spherical end face 11 of the optical fiber 1 and the light receiving element 21 is air. Therefore, n 1 is 1.
- the refractive index of PMMA (polymethinolemethacrylate), which is the core material of the optical fiber 1 is approximately 1.5 (here, calculated as 1.5). Therefore, the above relational expressions (1) and (2) are
- Equation (1 ') indicates that the light receiving surface of the light receiving element 21 is not in contact with the spherical end surface 11 of the optical fiber 1, and the force exceeds the distance corresponding to twice the radius of curvature of the spherical end surface 11. This indicates that the optical fiber 1 is not separated from the spherical end face 11 of the optical fiber 1.
- Equation (2,) indicates that the light receiving surface of the light receiving element 21 is separated from the spherical end face 11 of the optical fiber 1 by a distance equal to or greater than the diameter of the optical fiber 1, but is twice the radius of curvature of the spherical end face 11. This indicates that the optical fiber 1 is not separated from the spherical end face 11 of the optical fiber 1 beyond the distance corresponding to.
- the distance Separation d when the output NA of the optical fiber 1 is around 0.5 (that is, 0.4 to 0.6), which is used at medium speed transmission, that is, at a transmission rate of about 100 to 200 Mbs, the distance Separation d
- Figs. 4 to 6 show the dependence of the reception coupling efficiency on the distance between the end face and the receiver when the output NA of the optical fiber 1 is 0.35 in the optical communication system having the configuration shown in Fig. 1.
- the horizontal axis shows the distance between the end face and the receiver in the form of the ratio to the fiber diameter D.
- the end surface radius of curvature R and the PD diameter, which are parameters, are expressed using the fiber diameter D.
- ⁇ 5D shows the case where the PD diameter is ⁇ 5D
- Fig. 5 shows the case where the PD diameter is 1D
- Fig. 6 shows the case where the PD diameter is 1.5D
- ⁇ , ⁇ , and ⁇ represent the cases where the end surface curvature radius R is 2D, 1.5D, and D, respectively.
- the “receiver” refers to the photodiode 21.
- Figs. 10-11 show the effects on the reception coupling efficiency shown in the graphs of Figs.
- ⁇ indicates that the receiving coupling efficiency is 1.01 times or more that of the flat end face fiber.
- ⁇ indicates that the reception coupling efficiency is 0.99 to 1.01 times that of the flat end face fiber.
- X indicates that the receiving coupling efficiency is 0.99 times or less than that of the flat end fiber.
- FIGS. 7 to 9 are graphs similar to FIGS. 4 to 6 when the fiber emission NA defined by the intensity of 1 Ze 2 when the fiber emission end face is a flat surface corresponds to 0.5.
- an LED is used as the light source (light emitting element) at a transmission rate of 100 to 200 Mbps
- Fig. 7 shows the case where the PD diameter is 0.5D
- Fig. 8 shows the case where the PD diameter is 1D
- Fig. 9 shows the case where the PD diameter is 1.5D.
- Figs. 13 to 15 show the effects on the reception coupling efficiency shown in the graphs of Figs. As in Figs. 10 to 12, ⁇ indicates that the reception coupling efficiency is 1.01 times or more that of the flat-ended fiber. ⁇ indicates that the receiving coupling efficiency is 0.99 to 1.01 times that of the flat end face fiber. X indicates that the receiving coupling efficiency is 0.99 times or less than that of the flat end face fiber.
- the effect of improving the reception efficiency in this case is that the NA of the light emitted from the fiber specified by the intensity of lZe 2 is 0.35 compared to the case where the NA is 0.35.
- the reception efficiency is improved from the vicinity of the fiber end face to the 2D position compared to the case where the fiber end face is flat.
- the PD diameter is smaller than the fiber diameter D, it can be seen that the smaller the radius of curvature R of the end face, the higher the reception efficiency (however, when the distance d is up to 1D).
- the PD diameter becomes larger than the fiber diameter D in the range from near the fiber end face D to the 2D position, It can be seen that although the degree is small, there is an effect of improving the reception efficiency.
- FIGS. 16 and 17 show the case where the diameter of the light receiving element 21 is 0.5 D.
- the output NA from the fiber specified by the intensity of 1 / e 2 is 0.35 and 0.3.
- 5 is a graph comparing the distance dependence of the reception coupling efficiency when the radius of curvature R of the fiber spherical end face 11 is changed when the fiber end face is flat when the fiber end face is flat. From these graphs, when the fiber end face is a spherical end face, the reception efficiency (coupling efficiency) within the distance range defined by the above equations (1) and (3) is higher than when the fiber end face is a flat face. ) Can be increased.
- the radius of curvature R of the spherical end face 11 is D and the distance d is near 0.5D, even if the NA of the light emitted from the optical fiber is 0.35 or 0.5, It can be seen that the coupling efficiency is greatly improved compared to the end face fiber.
- the distance d is within the predetermined range, for the same distance d, it can be said that the smaller the radius of curvature R of the end face, that is, the larger the curvature, the higher the coupling efficiency.
- Fig. 18 shows that when the output end face of the fiber is flat and the NA output from the fiber specified by the intensity of lZe 2 corresponds to 0.35, the distance d is used as a parameter, and the light-receiving element diameter ( 7 is a graph in which the dependence on the PD diameter is plotted.
- Figure 18 shows that the smaller the PD diameter, the more effective it is, especially when the PD diameter is smaller than the fiber diameter 1D.
- the PD diameter is smaller than the fiber diameter 1D, especially when the fiber diameter is about 0.9 D or less, it can be seen that the reception efficiency is higher when the distance d is 1D than when the distance d is 1.5D.
- the PD diameter is smaller than the fiber diameter D, it can be said that setting the distance d to a value up to 1D is more effective.
- Figure 19 is equivalent to the exit NA is 0.35 from fiber-I Ba 1 fiber emission end surface is defined at an intensity of 1 / e 2 when the flat surface, the optical fiber diameter lmm, the curvature of the fiber spherical end face 1 1
- It is a graph comparing the calculated value and the actual measurement result when the radius is 1.5 mm and the PD diameter is 1 mm. Both are almost the same and show the same tendency.
- the distance between the end face and the receiver shown on the horizontal axis that is, the distance d
- a coupling efficiency of more than 30% can be obtained. It has been confirmed that the coupling efficiency approaches 100% as the end face 11 is approached.
- the diameter is 0.5 to 2 mm
- a fiber diameter of l mm is generally used from the viewpoint of ease of use, that is, ease of connection, and suppression of mode dispersion.
- the transmission rate of high-speed communication generally used for plastic optical fibers is 100 Mbps to 62 Mbps
- the PD diameter suitable for the transmission rate is 0.3 to 0.5 mm. is there. This combination of the fiber diameter and the PD diameter almost coincides with the range in which the effect of the present invention can be obtained most.
- FIG. 2 is a schematic diagram of a second embodiment of the optical communication system of the present invention.
- the second embodiment differs from the first embodiment in that an optical system is provided in each of the communication modules 2A and 2B.
- the same components as those shown in FIG. 1 are denoted by the same reference numerals as those used in FIG.
- reference numerals 25 and 26 denote a receiving optical system and a transmitting optical system, respectively.
- the receiving optical system 25 is disposed between the light receiving element 21 and the spherical end face 11 of the optical fiber 1, and functions to guide the light emitted from the spherical end face 11 to the light receiving element 21.
- the transmission optical system 26 functions to guide the light emitted from the light emitting element 22 to the end face of the optical fiber 1.
- the receiving optical system 25 and the transmitting optical system 26 include, for example, a member that refracts light such as a prism and a lens formed of a material having a different refractive index from air, a member that reflects light such as a mirror, and the like. It is.
- a transparent mold member (not shown) having a different refractive index from air is formed on the light receiving element 21, the mold member is also regarded as a component of the reception optical system 25. I have. Since such a receiving / transmitting optical system is widely known to those skilled in the art, the specific configuration will not be described in detail here.
- a lens part may be formed integrally with a transparent mold member.
- the relational expressions (1) to (4) established between the light receiving element 21 and the spherical end face 11 of the optical fiber 1 are represented by the following. It is established between the spherical end face 11 and the optical fiber 1. That is, in the first embodiment, the distance from the vertex of the spherical end face 11 of the optical fiber 1 to the light receiving surface of the light receiving element 21 is defined as d by the equations (1) to (4). In the second embodiment, the distance from the vertex of the spherical end face 11 of the optical fiber 1 to the center of the receiving optical system 25 is defined as d by the equations (1) to (4). In the first embodiment, the optical fiber 10543
- the “center position of the receiving optical system 25” is, as described above, the incident side principal point of the principal ray from the optical fiber 1 to the receiving optical system 25.
- the “size of the receiving optical system” is the diameter of a portion where light is optically condensed when the shape is circular, such as a condenser lens, and is optically light when the shape is not circular. Shall be the representative dimensions of the light-collecting part.
- a non-circular optical system is an elliptical mirror. In this case, the average size of the cross section perpendicular to the optical axis at the principal point on the elliptical mirror incident side is defined as the size of this optical system.
- the same effect of improving the reception efficiency as in the first embodiment was obtained.
- the present invention it is possible to dispose a small receiving optical system that condenses light on a light receiving element.
- FIG. 20 is a schematic configuration diagram of an optical communication system employing a single-core bidirectional optical communication system according to a third embodiment of the present invention.
- FIG. 21 is an enlarged view of a part of FIG. It is.
- the same components as those shown in FIGS. 1 and 2 are denoted by the same reference numerals as those used in FIGS. 1 and 2, and detailed description is omitted.
- the optical communication system of the first and second embodiments employs the one-way communication system, and the two cooperating optical communication modules 2A and 2B are not equipped with one of the light receiving element and the light emitting element.
- the two optical communication modules 2A and 2B that constitute the optical communication system of the third embodiment together with the plastic optical fiber 1 have both the light emitting element 22 and the light receiving element 21. Function as a transmitting / receiving module.
- Each of the optical communication modules 2A and 2B further includes a transmission optical system 26 and a reception optical system 25.
- the light receiving and emitting elements 21 and 22 and the transmitting and receiving optical systems 25 and 26 are connected to the receiving optical system 25 according to the NA of the light emitted from the optical fiber end face 11 and the size of the receiving optical system 25.
- the center position is arranged so as to satisfy any of the above equations (1) to (4).
- the light emitting and receiving elements 21 and 22 are connected to the optical fiber end face 1 1
- the light receiving and emitting elements 21 and 22 themselves occupy a large area relative to the end face 11 of the optical fiber when including the holding area, it is necessary to separate the transmitting and receiving elements. Such an arrangement is not possible, but not very realistic.
- the light path is converted between the optical fiber end face and the light emitting and receiving element between the optical fiber end face and the light receiving and emitting element in order to effectively split the transmitted and received light at the small optical fiber end face.
- Optical system is provided.
- the transmitting and receiving optics must be small enough to accommodate small optical fiber end faces.
- the receiving optical system is too small, the loss of received light will increase if no action is taken. For example, as shown in FIG. 22, half of the received light 15 is kicked by the transmission optical system 26.
- the size of the receiving optical system 25 is increased as shown in FIG. 23, the transmitted light 16 may not be coupled to the optical fiber end face 11. As shown in Fig.
- the receiving optical system 25 depends on the NA of the light emitted from the optical fiber end face 11 and the size of the receiving optical system 25 according to the above equation ( 1) Since it is located at a position that satisfies either of (4), it cannot be helped by the transmitting optical system 26, but even if the receiving optical system 25 is small, it can efficiently receive light, and the light receiving element The received light 15 can be guided to the photodiode 2.
- the present invention has been described through the three embodiments. However, the configurations other than the configurations described in the claims are not limited to those described in the above embodiments, including the materials, and may be appropriately changed. ⁇ Additional !!
- the present invention even if a large-diameter plastic optical fiber is used as the transmission medium and the light-receiving element is a small-sized light-receiving element for high-speed communication, a high optical coupling efficiency can be achieved with a simple configuration. Obtainable.
- the diameter of the plastic optical fiber is 1 mm, which is commonly used, and the light receiving element is a small high-speed photodiode with a diameter of 0.5 mm or less, it is possible to increase the reception efficiency. It is effective.
- the communication system is a single-core bidirectional optical communication system in which bidirectional communication is performed through one optical fiber
- the light receiving element and the receiving optical system can be reduced, so that the transmission system This is effective from the viewpoint of arranging in parallel.
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- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Optical Couplings Of Light Guides (AREA)
Abstract
Description
Claims
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
AU2003262261A AU2003262261A1 (en) | 2002-08-22 | 2003-08-21 | Optical communication system |
US10/525,437 US7218813B2 (en) | 2002-08-22 | 2003-08-21 | Optical communication system |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2002/241982 | 2002-08-22 | ||
JP2002241982A JP3869774B2 (ja) | 2002-08-22 | 2002-08-22 | 光通信システム |
Publications (1)
Publication Number | Publication Date |
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WO2004019099A1 true WO2004019099A1 (ja) | 2004-03-04 |
Family
ID=31944006
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2003/010543 WO2004019099A1 (ja) | 2002-08-22 | 2003-08-21 | 光通信システム |
Country Status (5)
Country | Link |
---|---|
US (1) | US7218813B2 (ja) |
JP (1) | JP3869774B2 (ja) |
CN (1) | CN100462757C (ja) |
AU (1) | AU2003262261A1 (ja) |
WO (1) | WO2004019099A1 (ja) |
Families Citing this family (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP3869774B2 (ja) * | 2002-08-22 | 2007-01-17 | シャープ株式会社 | 光通信システム |
JP2006238097A (ja) * | 2005-02-25 | 2006-09-07 | Fuji Photo Film Co Ltd | 光通信システム |
US8965204B2 (en) | 2011-05-10 | 2015-02-24 | Invensys Systems, Inc. | Multi-drop optical communication |
TWI509300B (zh) * | 2011-12-14 | 2015-11-21 | Hon Hai Prec Ind Co Ltd | 光耦合模組及其製作方法 |
CN104280829A (zh) * | 2013-07-05 | 2015-01-14 | 深圳市中技源专利城有限公司 | 单芯双向塑料光纤系统及塑料光纤连接器 |
CN109407237A (zh) * | 2018-12-29 | 2019-03-01 | 刘向宁 | 一种单芯光纤双向光耦合器 |
CN111580213B (zh) * | 2020-06-18 | 2023-01-31 | 中国建筑材料科学研究总院有限公司 | 双直区弯曲形光学纤维锥及其应用 |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH0326103U (ja) * | 1989-07-21 | 1991-03-18 | ||
JP2002031727A (ja) * | 2000-07-14 | 2002-01-31 | Sharp Corp | 光ファイバケーブル及びその端面加工方法 |
JP2002221627A (ja) * | 2001-01-24 | 2002-08-09 | Yazaki Corp | 光ファイバの製造方法 |
Family Cites Families (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4137060A (en) * | 1977-07-18 | 1979-01-30 | Robert Bosch Gmbh | Method of forming a lens at the end of a light guide |
JPH0326103A (ja) | 1989-06-23 | 1991-02-04 | Fujitsu Ten Ltd | データ多重ラジオ放送の受信装置 |
US5133709A (en) * | 1990-02-23 | 1992-07-28 | Prince Martin R | Optical fiber with atraumatic rounded end for use in laser angioplasty |
US5504828A (en) * | 1994-06-29 | 1996-04-02 | International Business Machines Corporation | Apparatus for extending bandwidth of large core fiber optic transmission links |
JPH10221573A (ja) | 1997-02-10 | 1998-08-21 | Yasuhiro Koike | 光ファイバと受光素子との結合構造 |
JP3653402B2 (ja) * | 1998-05-27 | 2005-05-25 | シャープ株式会社 | 光送受信モジュール |
JP3767842B2 (ja) * | 1998-11-02 | 2006-04-19 | ローム株式会社 | 双方向の光通信用モジュール |
US6243508B1 (en) * | 1999-06-01 | 2001-06-05 | Picolight Incorporated | Electro-opto-mechanical assembly for coupling a light source or receiver to an optical waveguide |
JP3869774B2 (ja) * | 2002-08-22 | 2007-01-17 | シャープ株式会社 | 光通信システム |
-
2002
- 2002-08-22 JP JP2002241982A patent/JP3869774B2/ja not_active Expired - Fee Related
-
2003
- 2003-08-21 WO PCT/JP2003/010543 patent/WO2004019099A1/ja active Application Filing
- 2003-08-21 US US10/525,437 patent/US7218813B2/en not_active Expired - Fee Related
- 2003-08-21 CN CNB038224941A patent/CN100462757C/zh not_active Expired - Fee Related
- 2003-08-21 AU AU2003262261A patent/AU2003262261A1/en not_active Abandoned
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH0326103U (ja) * | 1989-07-21 | 1991-03-18 | ||
JP2002031727A (ja) * | 2000-07-14 | 2002-01-31 | Sharp Corp | 光ファイバケーブル及びその端面加工方法 |
JP2002221627A (ja) * | 2001-01-24 | 2002-08-09 | Yazaki Corp | 光ファイバの製造方法 |
Also Published As
Publication number | Publication date |
---|---|
US7218813B2 (en) | 2007-05-15 |
JP2004078109A (ja) | 2004-03-11 |
US20050232537A1 (en) | 2005-10-20 |
CN100462757C (zh) | 2009-02-18 |
JP3869774B2 (ja) | 2007-01-17 |
AU2003262261A1 (en) | 2004-03-11 |
CN1685260A (zh) | 2005-10-19 |
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