JP2005123778A - Optical composite component and optical transmission system employing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical composite component that has both a function of an optical demultiplexer / multiplexer for optical signals within a particular wavelength band and other bands than the particular wavelength band, and a function of an optical divider for optical signal with the particular wavelength band, and distributes one wavelength of an optical signal subjected to wavelength multiplexing by a one system of optical fiber to a plurality of paths. <P>SOLUTION: The optical composite component 200 which has an optical filter 203 with characteristics of transmitting part of light with the particular wavelength band and reflecting the other light with the particular wavelength band and light other than the particular wavelength band, is used for photoelectric conversion sections 113a to 113c. Since the photoelectric conversion sections 113a to 113c are connected in cascade, and the photoelectric conversion sections 113a to 113c sequentially branch the optical signal and convert the signal into an electric signal while demultiplexing only the optical signal with the particular wavelength band from the optical signal other than the particular wavelength band subjected to wavelength multiplex transmission, the light with the particular wavelength band of the optical wavelength multiplex signal is distributed to a plurality of the photoelectric conversion sections 113a to 113c. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an optical transmission system that optically transmits information signals and the like, and more particularly to an optical transmission system that transmits a plurality of signals by wavelength multiplexing, and an optical composite component used in the optical transmission system, and more More specifically, the present invention relates to an optical composite component having optical demultiplexing / multiplexing characteristics and optical branching / coupling.

In recent years, with the spread of mobile phones, in order to improve the convenience of users, mobile communication services are provided even indoors or in tunnels where radio waves from base stations installed outdoors are not received It is demanded. Although the reach of radio waves is narrow indoors and in tunnels, in order to provide a wide range of services with a small number of base stations, an optical transceiver and optical fiber that connects signals from the base station to the mobile terminal are connected to the base station. A system is used that distributes and transmits signals to a plurality of optical transceiver units using an optical fiber and transmits signals from the mobile terminal received by the plurality of optical transceiver units to the optical transceiver master unit using an optical fiber. . In addition, in order to reduce the number of optical fibers connecting the optical transmission / reception master unit and the optical transmission / reception slave unit, an optical transmission system that multiplex-transmits light of different wavelengths has also been proposed. Such a conventional optical transmission system has a configuration as shown in FIG. 26 (see, for example, Patent Document 1). The optical transmission / reception master unit 51 and a plurality of optical transmission / reception slave units 53, 54, and 55 are connected by optical fibers 60 and 61, and the optical transmission / reception master unit 51 transmits a downstream signal to each optical transmission / reception slave unit, respectively. , 8 and 9, electrical / optical conversion, optical demultiplexer / multiplexer 13 multiplexes and transmits by optical fiber 60, and optical demultiplexers 53, 54, 55 receive optical demultiplexers / multiplexers. 64, 65, and 66 select the corresponding received signal, and the receiving circuit 2 performs optical / electrical conversion. On the other hand, the upstream signal is subjected to electrical / optical conversion by the electrical / optical conversion unit 3 of each of the optical transceivers 53, 54, 55, and is multiplexed by the optical demultiplexers / multiplexers 67, 68, 69 to be optical fiber 61. In the optical transmission / reception master unit 51, the optical demultiplexing / multiplexing unit 14 separates the signals into the optical transmission / reception slave units 53, 54, and 55, and the optical / electrical conversion units 10, 11, and 12 perform optical / electrical conversion. Was. In some cases, an upstream / downstream optical signal is bidirectionally transmitted through a single optical fiber with the optical wavelength of the upstream signal transmitted through the optical fiber being different from the optical wavelength of the downstream signal.
JP-A-4-48832 (page 4-5, FIG. 2)

  However, in the conventional configuration, since optical signals having different wavelengths must be used for the optical transceiver units 53, 54, and 55, the optical transceiver master unit 51 has the same number of wavelengths as the optical transceiver units. Different light emitting elements are required. In particular, when a signal from a base station to a mobile terminal is transmitted to a plurality of optical transceiver units using an optical fiber in mobile communications, the optical transceiver master unit 51 to the optical transceiver units 53, 54, 55 However, even in such a case, there is a problem that the same number of electrical / optical conversion units as that of the optical transceiver are required. In addition to mobile communications, even when video signals and data signals are transmitted optically in analog or digital form, when part of the transmission signal is branched / distributed while performing wavelength division multiplexing transmission of light. Had similar challenges.

  The present invention solves the above-described conventional problems, and provides an optical transmission system that enables signal transmission to a plurality of optical transceivers by a small number of transmitters in the optical transceiver, and an optical composite component used therefor The purpose is to do.

  In the optical composite component of the first invention, an optical filter is disposed on the first optical path at an angle other than a right angle to the first optical path, and the reflection position from the first optical path with respect to the optical filter is An optical composite component having a demultiplexing characteristic, wherein a second optical path is provided at a position where a third optical path is provided at a position that is a transmission position from the first optical path with respect to the optical filter, The optical filter has a characteristic of reflecting a part of light in a specific wavelength region and transmitting another part of light in the specific wavelength region and light having a wavelength outside the specific wavelength region.

  According to the first invention, with a simple configuration, the function of an optical demultiplexer that selects only light within the specific wavelength range and the function of an optical branching device that extracts only a part of the light within the specific wavelength range. Optical composite parts that have both can be realized.

  The optical composite component of the second invention is an invention dependent on the first invention, and the first, second, and third lights are located near the focal positions of the first, second, and third lenses, respectively. An input / output end of the fiber is disposed to convert the output light from the first, second, and third optical fibers into first, second, and third substantially parallel optical paths, or first, second, By configuring the third substantially parallel optical path to be incident light on the first, second, and third optical fibers, the first, second, and third optical paths in the first invention are The first, second, and third substantially parallel optical paths are used.

  According to the second invention, the function of the optical demultiplexer that selects only the light within the specific wavelength range and the optical branching device that extracts only a part of the light within the specific wavelength range using the optical fiber as the transmission line An optical composite part having both functions can be easily realized.

  Furthermore, the optical composite component of the third invention has the input / output ends of the first and second optical fibers disposed in the vicinity of one of the two focal planes of the first lens. The first and second optical fibers are arranged so as to be substantially parallel, and when light is emitted from the first optical fiber, a part of the light converted into substantially parallel light by the first lens is reflected. An optical filter is disposed in the vicinity of another focal plane of the first lens at an angle that is collected by the first lens and incident on the second optical fiber, and substantially parallel light is generated by the first lens. A second optical fiber is provided in the optical path that has passed through the optical filter, and the third optical fiber is coupled to the light condensed near the focal plane by the second lens. An optical composite part having a demultiplexing characteristic, wherein the optical Filter is to reflect part of the light in a specific wavelength range, has another and a portion of the specific wavelength range of light, a configuration in which a characteristic of transmitting light of a wavelength of said specific wavelength outside.

  According to the third aspect of the present invention, the function of the optical demultiplexer that selects only the light within the specific wavelength range and the light within the specific wavelength range using the optical fiber as the transmission path using fewer lenses, An optical composite part having the function of an optical branching device that extracts only a part can be easily realized.

  Furthermore, the optical composite component of the fourth invention is an invention subordinate to the first invention, and has a configuration in which a light receiving element is provided in the second optical path.

  According to the fourth aspect of the invention, in addition to the function of the optical demultiplexer that selects only the light within the specific wavelength range and the function of the optical branching unit that extracts only a part of the light within the specific wavelength range, An optical composite component that also has a function of converting a part of the optical signal within the specific wavelength range into an electric signal can be easily realized.

  Furthermore, the optical composite component of the fifth invention is an invention dependent on the second or third invention, wherein the second optical fiber is replaced with a light receiving element provided at an optical fiber input / output end surface position. It has a configuration.

  According to the fifth aspect of the invention, the function of the optical demultiplexer that selects only the light within the specific wavelength range and the optical branching device that extracts only a part of the light within the specific wavelength range using the optical fiber as the transmission line. In addition to this function, it is possible to easily realize an optical composite component that also has a function of converting a part of the optical signal in the specific wavelength range into an electrical signal.

  Furthermore, the optical composite component of the sixth invention is an invention subordinate to the first invention, and has a configuration in which a light emitting element is provided in the second optical path.

  According to the sixth aspect, the function of converting an electrical signal into an optical signal, the function of an optical coupler that couples the optical signal with another optical signal within a specific wavelength range, and the optical coupling within the specific wavelength range An optical composite component having both the function of an optical multiplexer that combines an optical signal with an optical signal outside the specific wavelength range can be easily realized.

  Furthermore, the optical composite component of the seventh invention is an invention dependent on the second or third invention, wherein the second optical fiber is replaced with a light emitting element provided at an optical fiber input / output end surface position. It has a configuration.

  According to the seventh aspect, the function of converting an electrical signal into an optical signal using an optical fiber as a transmission line, the function of an optical coupler that couples the optical signal with another optical signal in a specific wavelength range, Thus, an optical composite component having the function of an optical multiplexer that combines the combined optical signal within the specific wavelength region with the optical signal outside the specific wavelength region can be easily realized.

  Furthermore, the optical composite component of the eighth invention is an invention dependent on any one of the first to seventh inventions, and the optical filter has a light reflectance of 60% or less in the specific wavelength region. It has a configuration.

  According to the eighth aspect of the invention, it becomes possible to distribute the light in the specific wavelength region at a ratio close to equality.

  An optical composite component according to a ninth aspect of the invention is an invention dependent on the first aspect of the invention, wherein the optical filter transmits a part of the light in the specific wavelength range and the other light in the specific wavelength range is transmitted. A part of the optical filter is replaced with an optical filter having a characteristic of reflecting light having a wavelength outside the specific wavelength range.

  According to the ninth aspect, with a simple configuration, the function of an optical demultiplexer that selects only light within the specific wavelength range and the function of an optical branching device that extracts only a part of the light within the specific wavelength range. Optical composite parts that have both can be realized.

  Furthermore, an optical composite component of a tenth invention is an invention dependent on the second or third invention, wherein the optical filter transmits a part of light in a specific wavelength region, and the light in the specific wavelength region is transmitted. And another optical filter having a characteristic of reflecting light having a wavelength outside the specific wavelength range.

  According to the tenth aspect of the invention, the function of the optical demultiplexer that selects only the light within the specific wavelength range and the optical branching device that extracts only a part of the light within the specific wavelength range using the optical fiber as the transmission line. An optical composite part having both functions can be easily realized.

  Furthermore, an optical composite component of the eleventh aspect of the invention is an invention dependent on the ninth aspect of the invention, and has a configuration in which a light receiving element is provided in the third optical path.

  According to the eleventh aspect of the invention, in addition to the function of the optical demultiplexer that selects only the light within the specific wavelength range and the function of the optical branching unit that extracts only a part of the light within the specific wavelength range, An optical composite component that also has a function of converting a part of the optical signal within the specific wavelength range into an electric signal can be easily realized.

  Furthermore, an optical composite component of a twelfth aspect of the invention is an invention dependent on the tenth aspect of the invention, wherein the optical filter transmits a part of the light in the specific wavelength range and the other light in the specific wavelength range is transmitted. A part of the optical filter is replaced with an optical filter having a characteristic of reflecting light having a wavelength outside the specific wavelength range.

  According to the twelfth aspect of the present invention, the function of the optical demultiplexer that selects only the light within the specific wavelength range and the optical branching device that extracts only a part of the light within the specific wavelength range using the optical fiber as the transmission line. In addition to this function, it is possible to easily realize an optical composite component that also has a function of converting a part of the optical signal in the specific wavelength range into an electrical signal.

  Furthermore, an optical composite component of a thirteenth aspect of the invention is an invention dependent on the third aspect of the invention, wherein the optical filter transmits a part of light in a specific wavelength range, and other light in the specific wavelength range is transmitted. Replace with a part and an optical filter having a characteristic of reflecting light of a wavelength outside the specific wavelength range, and replace the third optical fiber with a light receiving element provided at the position of the optical fiber input / output end surface, and are arranged almost in parallel The distance between the centers of the incident and exit end faces of the first and second optical fibers is wider than the maximum width of the light receiving surface range having the light receiving sensitivity of the light receiving element.

  According to the thirteenth aspect, leakage of an optical signal incident from the second optical fiber into the light receiving element can be suppressed, and crosstalk can be reduced.

  Furthermore, the optical composite component of the fourteenth invention is an invention dependent on the ninth invention, and has a configuration in which a light emitting element is provided in the third optical path.

  According to the fourteenth aspect, the function of converting an electrical signal into an optical signal, the function of an optical coupler that couples the optical signal with another optical signal within a specific wavelength range, and the optical coupling within the specific wavelength range An optical composite component having both the function of an optical multiplexer that combines an optical signal with an optical signal outside the specific wavelength range can be easily realized.

  Further, the optical composite component of the fifteenth invention is an invention dependent on the tenth invention, wherein the third optical fiber is replaced with a light emitting element provided at an optical fiber input / output end face position. doing.

  According to the fifteenth aspect, the function of converting an electrical signal into an optical signal using an optical fiber as a transmission line, the function of an optical coupler that couples the optical signal with another optical signal in a specific wavelength range, Thus, an optical composite component having the function of an optical multiplexer that combines the combined optical signal within the specific wavelength region with the optical signal outside the specific wavelength region can be easily realized.

  The optical composite component of the sixteenth invention is an invention dependent on any one of the ninth to fifteenth inventions, wherein the optical filter has a light transmittance of 60% or less in the specific wavelength region. It has a configuration.

  According to the sixteenth aspect, light in the specific wavelength range can be distributed at a ratio close to equality.

  Next, an optical composite component of a seventeenth invention is an invention dependent on any one of the first to sixteenth inventions, wherein the optical filter is formed of an interference film filter using a thin film multilayer. Have.

  According to the seventeenth aspect of the present invention, a light having both the function of a branching filter and a branching device, in which only a part of light in a specific wavelength region is extracted by a filter created by a general series of processes for forming a thin film. A composite part can be realized.

  An optical composite component of an eighteenth aspect of the invention is an invention dependent on any of the ninth to fifteenth aspects of the invention, wherein the optical filter transmits light in a specific wavelength range and has a wavelength other than the specific wavelength range. And a half-mirror layer that transmits part of the light in all the wavelength ranges to be used and reflects the other light.

  According to the eighteenth aspect of the present invention, a branching filter and a branching device that extract only a part of light in a specific wavelength range using a general specific wavelength range transmission filter and a half mirror layer that have been used conventionally. It is possible to realize an optical composite part that also has the function of a vessel.

  Furthermore, the optical composite component of the nineteenth invention is an invention dependent on any one of the ninth to fifteenth inventions, wherein the optical filter transmits light in a specific wavelength range and has a wavelength other than the specific wavelength range. And a half-mirror layer that transmits part of the light in all the wavelength bands used and reflects other light.

  According to the nineteenth aspect of the present invention, it has the function of both a duplexer and a branching device that extracts only a part of light in a specific wavelength range by combining optical thin film designs that are generally used conventionally. An optical composite part can be realized.

  Furthermore, the optical composite component of the twentieth invention is an invention subordinate to the eighteenth or nineteenth invention, wherein the light other than the specific wavelength band is on the side of the specific wavelength band transmission filter of the optical filter. It has the structure installed in the direction which injects from.

  According to the twentieth aspect, the reflection loss due to the half mirror layer is reduced.

  Next, an optical transmission system according to a twenty-first invention is an invention dependent on any one of the first to twentieth inventions, wherein a plurality of electrical / optical conversion units or optical / electrical conversion units are sequentially connected to the main system light. An optical transmission system connected in cascade with a fiber, wherein each of the plurality of electrical / optical conversion units or optical / electrical conversion units uses the optical composite component according to the first to twentieth inventions, and is transmitted with a main system optical fiber. The optical signal having a wavelength within the specific wavelength range is branched or combined.

  According to the twenty-first aspect, an optical signal within the specific wavelength range can be branched into two or more by a simple configuration in which optical composite components are cascade-connected to one main system optical fiber, or within the specific wavelength range An optical transmission system that can combine two or more optical signals is realized.

  An optical transmission system according to a twenty-second invention is an invention dependent on the twenty-first invention, wherein the main system optical fiber has an optical signal having a wavelength within the specific wavelength range and a wavelength outside the specific wavelength range. The optical signal is wavelength-multiplexed.

  According to the twenty-second aspect of the present invention, the light within the specific wavelength range is not affected by the simple configuration of cascading optical composite components to one main system optical fiber without affecting the optical signal outside the specific wavelength range. An optical transmission system capable of branching a signal into two or more or combining two or more optical signals within the specific wavelength band is realized.

  Furthermore, an optical transmission system according to a twenty-third invention is an invention dependent on any one of the second to fifth, eleventh, or thirteenth inventions, wherein a plurality of optical transceiver units are sequentially connected to the main system light. An optical transmission system connected in cascade with a fiber, wherein each of the plurality of optical transceivers connects an optical / electrical converter to the second optical fiber of the optical composite part of the second or third invention. Alternatively, an optical / electrical converter is connected to the third optical fiber of the optical composite part of the tenth invention, or an optical composite part having the light receiving element of the fourth, fifth, or eleventh to thirteenth inventions. An optical / electric conversion unit is used to branch and receive an optical signal having a wavelength within the specific wavelength range that is transmitted by the main system optical fiber, and each of the plurality of optical transceiver units is configured to receive the specific signal. Outside the wavelength range By connecting optical multiplexers corresponding to different wavelengths outside the specific wavelength range to electrical / optical converters that transmit optical signals of different wavelengths, light of different wavelengths outside the specific wavelength range is connected to the main optical fiber. It has a configuration for transmitting a signal.

  According to the twenty-third aspect, with a simple configuration in which the plurality of optical transceivers are cascade-connected to one main system optical fiber, signal light having a single wavelength within the specific wavelength range is transmitted to a plurality of light beams. It is possible to realize an optical transmission system that performs wavelength division multiplexing transmission of an optical signal having a wavelength outside the specific wavelength range while branching and receiving with a transceiver.

  An optical transmission system according to a twenty-fourth aspect of the invention is an invention dependent on the twenty-third aspect of the invention, wherein an optical transmission / reception master unit is connected to the main optical fiber so as to face the plurality of optical transmission / reception slave units. An optical transmission system that performs bidirectional optical signal transmission between a plurality of optical transceiver units and the optical transmission / reception master unit, wherein the optical transmission / reception master unit sends out the electrical / optical conversion unit of the plurality of optical transceiver units As a configuration having a plurality of optical / electrical converters that demultiplex and receive optical signals of different wavelengths outside the specific wavelength range, and an electrical / optical converters that transmit optical signals of wavelengths within the specific wavelength range Yes.

  According to the twenty-fourth aspect, an optical signal from one electrical / optical conversion unit provided in the optical transmission / reception master unit can be branched and received by a plurality of optical transmission / reception slave units. A transmission system can be realized.

  An optical transmission system according to a twenty-fifth aspect of the invention is an invention dependent on the twenty-third aspect of the invention, wherein an optical transmission / reception master unit is connected to the main optical fiber so as to face the plurality of optical transmission / reception units, An optical transmission system that performs bidirectional optical signal transmission between a plurality of optical transceiver units and the optical transceiver master unit, and the optical transceiver master unit sends out the electrical / optical conversion unit of the plurality of optical transceiver units An optical / electrical converter that receives a plurality of optical signals of different wavelengths out of the optical signals of different wavelengths outside the specific wavelength region; and an electrical / optical converter that transmits an optical signal of a wavelength within the specific wavelength region It has the composition to have.

  According to the twenty-fifth aspect, an optical signal from the plurality of optical transceiver units can be received by one optical / electrical converter provided in the optical transceiver master unit, and the configuration is further simplified. An optical transmission system can be realized.

  Next, an optical transmission system according to a twenty-sixth aspect of the invention is an invention dependent on the twenty-third aspect, wherein the optical transmission / reception master unit and the plurality of optical transmission / reception slave units are cascade-connected by a loop main system optical fiber. An optical communication system, wherein the optical transmission / reception master unit for transmitting an optical signal in the specific wavelength range, an optical / optical conversion unit of the optical transmission / reception master unit, a plurality of optical transmission / reception slave units, and the optical transmission / reception master unit for receiving an optical signal outside the specific wavelength range The optical / electrical converters are connected in cascade.

  According to the twenty-sixth aspect, an optical transmission system having a simple configuration can be realized without requiring an optical demultiplexer / multiplexer in the optical transmission / reception master unit.

  Furthermore, an optical transmission system according to a twenty-seventh aspect of the present invention is an optical transmission system in which a plurality of optical transceiver units are connected in cascade with a main system optical fiber, each of the plurality of optical transceiver units being a second or A light receiving element is connected to the second optical fiber of the optical composite component of the third invention to form a first optical / electrical change section, or the third light of the optical composite component of the tenth invention A light receiving element is connected to the fiber to form the first light / electricity changing section, or the first light is formed by using an optical composite part having the light receiving element of the fourth, fifth, or eleventh to thirteenth inventions. / Branching and receiving the optical signal of the wavelength within the specific wavelength range transmitted by the main system optical fiber by configuring the electrical conversion unit, and each of the plurality of optical transceivers is respectively outside the specific wavelength range Separate optical signals of different wavelengths An optical signal outside the characteristic wavelength range is received by a second optical / electrical converter comprising an optical multiplexer / demultiplexer that performs and an optical signal that converts the optical signal demultiplexed by the optical multiplexer / demultiplexer. It is configured.

  According to the twenty-seventh aspect of the present invention, a simple configuration in which the plurality of optical transceiver units are cascade-connected to one main optical fiber, and multiplexing of different optical signals to the respective optical transceiver units is performed. Transmission and distribution transmission of optical signals common to all can be performed simultaneously.

  According to the optical composite component of the present invention and the optical transmission system using the same, it is possible to extract only a part of light in a specific wavelength range with a simple configuration, for example, between an optical transmission / reception master unit and a plurality of optical transmission / reception slave units. Therefore, even when multiple signals are multiplexed and transmitted by wavelength multiplexing with a single optical fiber, a system such as branching / distributing only a specific signal among multiple signals to multiple optical transceiver units, etc. This can be realized with a simple configuration.

  Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1)
1 and 2 are a configuration diagram of an optical transmission system according to Embodiment 1 of the present invention and a configuration diagram of an optical composite component used for the system.

  In FIG. 1, an optical transmission system 101 has an optical transmission / reception master unit 102 and a plurality of optical transmission / reception slave units 103a, 103b, 103c cascaded by a single main system optical fiber 104a, 104b, 104c. Thus, an optical signal is transmitted between the plurality of optical transceiver units 103 a, 103 b, 103 c and the optical transceiver unit 102. The optical transmission / reception base unit 102 receives an input electrical signal from the outside, performs electrical signal processing such as amplification in the optical transmission circuit 104, and converts the light of wavelength λa into a modulated optical signal in the electrical / optical conversion unit 105. This optical signal is output to the main optical fiber 104a via the optical fiber 106 and the optical demultiplexer / multiplexer 107. The optical demultiplexer / multiplexer 107 connects light having a wavelength in the vicinity of the wavelength λa between the main optical fiber 104a and the optical fiber 106, and transmits light having wavelengths in the vicinity of the wavelengths λb1, λb2, and λb3 to the main optical fiber. It has a characteristic of connecting between 104a and the optical fiber 106. Optical signals of wavelengths λb1, λb2, and λb3 input from the main system optical fiber 104a to the optical demultiplexer / multiplexer 107 are converted into electric signals by the optical / electrical converter 109, and are amplified by the optical receiver circuit 110. Perform signal processing and output electrical signal.

  On the other hand, the optical transceivers 103a, 103b, and 103c have the same configuration, and the electrical / optical conversion units 111a, 111b, and 111c, the optical transmission circuits 112a, 112b, and 112c, and the optical / electrical conversion units 113a, 113b, and 113c. And optical receiving circuits 114a, 114b, and 114c, and the electrical / optical converters 111a, 111b, and 111c are connected in cascade by optical / electrical converters 113a, 113b, and 113c, and optical fibers 115a, 115b, and 115c, respectively. .

  Since the optical transceivers 103a, 103b, and 103c have the same configuration, detailed explanation and operation explanation will be given by taking the optical transceiver 103a as an example. The optical transmission circuit 112a receives an electric input signal and performs electric signal processing such as amplification. The electrical / optical converter 111a has the configuration shown in FIG. 4 and includes an optical demultiplexer / multiplexer 401 and a light emitting element 402, and converts an electrical signal from the optical transmission circuit 112a into an optical modulation signal having a wavelength λb3. At the same time, it is combined with the optical signal from the optical / electrical converter 113a (from B in the figure) and sent to the main optical fiber 104a (A in the figure) on the optical transmission / reception master unit 102 side. The optical transceivers 103b and 103c have the same configuration, but the characteristics of the light emitting element 402 are changed so that the wavelengths of the transmitted optical signals are different and become λb2 and λb1, respectively.

  The optical signal having the wavelength λa from the optical transmission / reception base unit 102 enters the optical / electrical converter 113a via the optical demultiplexer / multiplexer 401 and the optical fiber 115a of the electrical / optical converter 111a. The optical composite part of the present invention is used for the optical / electrical converter 113a, and FIG. 2 is a configuration diagram of one embodiment thereof. In the optical composite component 200, the gradient index rod lens 201 has a pitch of about 0.25 pitch. Therefore, the vicinity of both end surfaces thereof becomes the focal plane of the gradient index rod lens 201. Two optical fibers 202a and 202b are arranged substantially in parallel so that the end face is located near the focal plane. These two optical fibers 202a and 202b are connected to B and C shown in the portion of the optical transceiver 103a in FIG. 1 respectively, or are continuous optical fibers. ing. Further, the optical filter 203 is installed near another focal plane (that is, near the other end face) of the gradient index rod lens 201. The optical filter 203 has the characteristics of transmittance (solid line) and reflectance (broken line) shown in FIG. (An example of the wavelength arrangement of the optical signals λb3, λb2, λb1, and λa in the present embodiment is also indicated by a broken line in FIG. 3.) The characteristics of the optical filter 203 are characteristic as the optical composite component of the present invention. For light in a specific wavelength region near λa, part of the light (about 33% in FIG. 3) is transmitted and other light in the specific wavelength region (about 67% in FIG. 3). And has a characteristic of reflecting almost 100% of light in a wavelength range away from a specific wavelength range in the vicinity of λa. The characteristic of the optical filter shown in FIG. 3 is that, for example, as shown in FIG. 5, the interference film filter 502 is formed of a thin film multilayer on a transparent substrate 501 such as glass or resin. This can be realized by appropriately designing the film thickness. As the material of the thin film multilayer, a dielectric material or the like can be used. As a result, if the two optical fibers 202a and 202b are adjusted to appropriate positions, the optical signals of the wavelengths λb2 and λb3 from the optical fiber 202b (C in FIG. 2) on the side of the optical transceivers 103b and 103c will have a refractive index. Although it is converted into parallel light by the distributed rod lens 201, it is reflected by the optical filter 203, collected again, and coupled to the optical fiber 202 b (B in FIG. 2) on the optical transmission / reception master unit 102 side. On the other hand, the optical signal of wavelength λa from the optical fiber 202b is converted into parallel light by the gradient index rod lens 201, and about 67% is reflected by the optical filter 203 and condensed again, and the optical fiber 202a (in FIG. 2). C), but the remaining 33% is transmitted. In the optical composite component 200, a second gradient index lens 204 and a light receiving element 205 are installed on the opposite side of the optical filter 203, and an optical signal having a wavelength λa of about 33% transmitted through the optical filter 203 is obtained. Then, the light is condensed on the light receiving surface 205a of the light receiving element 205 by the gradient index lens 204 and is optically / electrically converted into an electric signal by the light receiving element 205. With this configuration, the optical composite component 200 of the present invention shown in FIG. 2 separates an optical signal in a specific wavelength region near the wavelength λa and an optical signal outside a specific wavelength region such as λb2 and λb3. The function of an optical demultiplexer / multiplexer for wave / combining, the function of an optical branching device for branching only a part of an optical signal near the wavelength λa to the light receiving element side, and the light / It functions as an optical component that also functions as an electrical converter. For example, when this function is constituted by conventional optical communication parts, as shown in FIG. 6, two optical demultiplexing / multiplexing units, an optical branching unit, and a light receiving element module are required. As a result, the configuration becomes complicated.

  The optical / electrical converters 113b and 113c used in the optical transceivers 103b and 103c are the same as those in FIG. 2, but it is desirable to change the characteristics of the optical filter 203, respectively. For example, the transmittance and reflectance for light in a specific wavelength region near λa are about 50% and about 50% when used for the optical / electrical converter 113b, respectively, and when used for the optical / electrical converter 113c. Set to about 100% and about 0%.

  The electrical signal obtained from the optical / electrical conversion unit 113a is electrically processed by amplification or the like in the optical receiving circuit 114a, and is output from the optical transceiver 103a as an output electrical signal. FIG. 1 shows a case where the optical transmission system 101 according to the first embodiment is applied to a mobile communication base station apparatus, and the optical transmission / reception base station 102 inputs and outputs electrical signals from the mobile communication base station apparatus 116. . The optical transceivers 103a, 103b, and 103c input and output electrical signals to and from the antenna duplexers 118a, 118b, and 118c, and the antennas 117a, 117b, and 117c connected to the antenna duplexers 118a, 118b, and 118c. Then, a radio signal communicating with a mobile terminal is transmitted / received.

  With this configuration, the optical transmission / reception master unit 102 connected to the mobile communication base station apparatus 116 and the optical transmission / reception slave units 103a, 103b, 103c connected to the plurality of antennas 117a, 117b, 117c are connected to one main system. In the configuration in which the optical fibers 104a, 104b, and 104c are connected in cascade, the optical signal having the wavelength λa from the electrical / optical converter 105 is distributed to the optical transceivers 103a, 103b, and 103c, and transmitted and received in the opposite direction. Optical signals from the slave units 103a, 103b, and 103c are sequentially combined and transmitted to the optical transmission / reception master unit 102, thereby enabling bidirectional optical transmission.

  The optical signal of wavelength λa from the electrical / optical converter 105 passes through the optical fiber 106, the optical demultiplexer / multiplexer 107, the main optical fiber 104a, the electrical / optical converter 111a, and the optical fiber 115a. About 33% is converted into an electrical signal by the optical / electrical converter 113a. The remaining 67% is transmitted through the main system optical fiber 104b and the optical fiber 115b, and about 50% is converted into an electric signal by the optical / electrical converter 113b. The remaining 50% passes through the main system optical fiber 104c and the optical fiber 115c, and is converted into an electric signal by the optical / electrical converter 113c. Therefore, there is a loss other than the reflection and transmittance of the optical / electrical converters 113a, 113b, 113c, such as the loss of the main system optical fiber 104b, the optical fiber 115b, the main system optical fiber 104c, and the optical fiber 115c with respect to the optical signal of λa. If negligible, the optical signal of wavelength λa from the electrical / optical converter 105 is distributed almost equally to the optical transceivers 103a, 103b, 103c, and the circuit design of the optical receiver circuit 114a and the like is facilitated. When the loss of the main system optical fiber 104b, the optical fiber 115b, the main system optical fiber 104c, and the optical fiber 115c is not negligible, the reflectance and transmittance for the specific wavelength region near the wavelength λa of the optical filter 203 are accordingly changed. By adjusting, it is possible to distribute the optical signal almost equally.

  As described above, according to the present embodiment, the characteristic of the optical filter 203 used in the optical composite component 200 is partially transmitted with respect to light in a specific wavelength region near λa, and the specific wavelength region is transmitted. In addition to reflecting other light, and having a characteristic of reflecting almost 100% of light in a wavelength region apart from a specific wavelength region near λa, an optical signal in a specific wavelength region near wavelength λa, and λb2, λb3 A function of an optical demultiplexer / multiplexer for demultiplexing / multiplexing an optical signal outside a specific wavelength region, such as an optical branching device for branching only a part of an optical signal near the wavelength λa to the light receiving element side; An optical composite component having the function of an optical / electrical converter that converts an optical signal into an electrical signal can be realized with a simple configuration.

  Further, according to the present embodiment, this optical composite component 200 is used in the optical transceivers 103a, 103b, 103c, and these are cascaded by one main system optical fiber 104a, 104b, 104c. Thus, the optical transmission / reception master unit 102 and the plurality of optical transmission / reception slave units 103a, 103b, 103c can transmit optical signals bidirectionally by wavelength multiplexing using only one optical fiber.

  As shown in FIG. 3, the optical filter 203 of the optical composite component 200 is preferably designed so that the transmittance with respect to λb1, λb2, and λb3 is almost 0%. Often occurs. In particular, the wider the wavelength band to be reflected with a transmittance of approximately 0%, the more difficult it is to keep the transmittance low in all the wavelength regions. Therefore, a part (for example, about 1%) of optical signals having wavelengths λb2 and λb3 incident from the optical fiber 202b in FIG. 2 is transmitted through the optical filter 203, and this transmitted light is indicated by a broken line in FIG. The light is condensed by the gradient index lens 204. When this transmitted light leaks into the light receiving element 205 and enters it, this incident light is also converted into an electrical signal, and noise of the electrical signal due to crosstalk increases. In order to prevent electrical signal noise due to the crosstalk, it is desirable that the distance d1 between the optical fibers 202a and 202b be larger than the maximum width d2 of the light receiving surface 205a of the light receiving element 205. The focal length of the optical system that converts the emitted light from the optical fiber 202b into substantially parallel light in the optical filter 203 and the focal length of the optical system that condenses the transmitted light of the optical filter 203 near the light receiving element 205 are approximately the same. Since there are many designs, the light condensing position is displaced by a distance substantially equal to the distance d1 between the optical fibers 202a and 202b. Therefore, this condensing position is outside the light receiving surface 205a of the light receiving element 205, and noise due to crosstalk can be reduced.

  In the present embodiment, in each of the optical transceivers 103a, 103b, and 103c, the optical / electrical converters 113a, 113b, and 113c are arranged with the electrical / optical converters 111a, 111b, and 111c facing the optical transceiver master 102. However, the same effect can be obtained even when the optical / electrical converters 113a, 113b, 113c are connected to the electric / optical converters 111a, 111b, 111c with the optical / electrical converters 113a, 113b, 113c on the transmission / reception master unit 102 side.

  In the present embodiment, the optical / electrical converter 113c has the same configuration as the optical / electrical converters 113a and 113b, but the optical / electrical converter of the optical transceiver slave farthest from the optical transceiver 102 is A conventional general light receiving element module in which an optical fiber and a light receiving element are optically coupled may be used.

  In the present embodiment, the case where three optical transceiver units 103a, 103b, and 103c are connected in cascade is illustrated, but the number of optical transceiver units is not limited, and the number is other than three. However, it goes without saying that the same effect can be achieved. However, in this case, it is desirable to adjust the reflectance and transmittance of the optical filter in order to evenly distribute the light of wavelength λa.

  In the present embodiment, it has been described that the characteristics shown in FIG. 3 of the optical filter 203 used in the optical composite component 200 can be realized by using the interference film filter 502 with a thin film multilayer as shown in FIG. In addition, as shown in FIG. 7, an interference film filter 702 using a thin film multilayer and a half mirror layer 703 can be laminated on a transparent substrate 701. The half mirror layer 703 can be formed of a metal thin film or the like. In the case of this configuration, the interference film filter 702 can have a characteristic of transmitting almost 100% of light in a specific wavelength band near the wavelength λa, and a conventional general optical filter design can be applied. In addition, when the characteristics of the optical filter 203 are changed by the optical transceivers 103a, 103b, and 103c, it is possible to change the characteristics of the half mirror layer 703. Either the interference film filter 702 or the half mirror layer 703 may be formed on the substrate side, but it should be noted that light outside a specific wavelength band must be arranged to enter from the interference film filter 702 side. is necessary.

  Further, as shown in FIG. 8, the optical filter 203 is close to a transparent substrate 801 formed with an interference film filter 802 formed of a thin film multilayer and a transparent substrate 804 formed with a half mirror layer 803. It is also possible to implement it. In the case of this configuration, the transparent substrate 801 on which the interference film filter 802 is formed and the transparent substrate 804 on which the half mirror layer 803 is formed have conventional general characteristics. There is an advantage that you can. In addition, when the characteristics of the optical filter 203 are changed by the optical transceivers 103a, 103b, and 103c, it is possible to replace only the transparent substrate 804 on which the half mirror layer 803 is formed with one having characteristics.

  Further, in the present embodiment, the optical composite component 200 is configured to use the gradient index rod lenses 201 and 204 as shown in FIG. 2, but these lenses need not necessarily be gradient index rod lenses. As shown in FIG. 9, the same effect can be obtained even if the optical composite component 900 is configured using the convex lenses 901 and 904 and the like. Furthermore, it is needless to say that the same effect can be obtained when the optical composite component 1000 is configured using a plurality of lenses 1004a and 1004b for condensing as shown in FIG. Furthermore, the same effect can be obtained when the end face is inclined obliquely in order to prevent the reflected return light from the end face of the gradient index rod lens or the optical fiber.

  Further, in the present embodiment, the optical / electrical converters 113a, 113b, 113c are configured by only the optical composite component 200 in which the light receiving element 205 is disposed at the light collection position by the gradient index lens 204 as shown in FIG. However, as shown in FIG. 11, the optical composite component 1100 in which the optical fiber 1102 is disposed at the condensing position by the gradient index lens 204, the optical fiber 1103 connected to the optical fiber 1102, and the light receiving element 205 are optically connected. And a light receiving module 1104 coupled to the. According to this configuration, the function of the optical demultiplexer / multiplexer for demultiplexing / multiplexing the optical signal in the specific wavelength region near the wavelength λa and the optical signal outside the specific wavelength region such as λb2 and λb3, and the wavelength λa An optical composite component 1100 having a function of an optical branching device that branches only a part of a nearby optical signal to the light receiving element side and an optical / electrical converter function of converting the optical signal into an electrical signal is realized with a simple configuration. The optical / electrical converters 113a, 113b, and 113c can be configured by combining this with a general light receiving module 1104.

  Further, in the present embodiment, the characteristics of the optical filter 203 used in the optical composite component 200 are partially transmitted with respect to light in a specific wavelength region near λa as shown in FIG. In addition to reflecting other light in the region, light in a wavelength region away from a specific wavelength region in the vicinity of λa reflects almost 100%, but the same effect can be obtained with an optical filter having the opposite property. Can do. FIG. 12 is a configuration diagram of an optical composite component 1200 in which the characteristics of the optical filter 203 of the optical composite component 1100 are reversed, taking the optical composite component 1100 shown in FIG. 11 as an example. The optical filter 1203 of the optical composite component 1200 has the characteristics as shown in FIG. 13 and reflects a part (about 33% in FIG. 13) of light in a specific wavelength region near λa. In addition, it transmits light of a specific wavelength range (approximately 67% in FIG. 13) and transmits light of a wavelength range away from the specific wavelength range near λa by approximately 100%. Similarly to FIG. 5, the optical filter 1203 having such characteristics can be manufactured by forming an interference film filter using a thin film multilayer on a transparent substrate. With this configuration, the same effects as those of the optical composite component 1100 shown in FIG. 11 can be obtained. However, in the optical composite component 1100 and the optical composite component 1200, the functions of the optical fiber 202b and the optical fiber 1102 are interchanged.

  Further, in the optical composite component of the present embodiment, as shown in FIGS. 2 and 9, the light that enters and exits the two optical fibers 202a and 202b is converted into a single gradient index lens 201 or convex lens 901. However, as shown in the configuration diagram of FIG. 14, the lens 1401 is added, and the light that enters and exits the optical fiber 202 b is condensed or converted into parallel light. Also good. Of course, it goes without saying that the same effect can be obtained even if a gradient index rod lens or a lens system using a plurality of lenses is used instead of the convex lenses 901 and 902 and the lens 1401 in FIG.

  Furthermore, in the optical composite component 200 of the present embodiment, a lens is used for focusing on the optical fibers 202a and 202b and the light receiving element 205, but the optical fiber, the light receiving element, and the optical filter are placed close to each other. If provided, a lens is not necessarily required. FIG. 15 is a configuration diagram of the optical composite component 1500 when no lens is used. An optical filter 1503 is disposed so as to be sandwiched between optical fibers 1502a and 1502b whose end faces are obliquely processed, and a light receiving element 1505 is provided close to a position where light emitted from the optical fiber 1502a toward the optical filter 1503 is reflected. . Also in this case, the characteristic of the optical filter 1503 is a feature of the present invention. In the case of FIG. 15, a part of the light in a specific wavelength region near λa is reflected as shown in FIG. In addition to transmitting other light in a specific wavelength region, light having a wavelength region away from the specific wavelength region in the vicinity of λa transmits almost 100%. With this configuration, an optical composite component 1500 having functions of an optical demultiplexing / multiplexing device, an optical branching / combining device, and a light receiving element module can be realized without a lens.

  In addition, an optical composite component having the same effect can be configured even if an optical waveguide is used. FIG. 16 is a plan view of the optical composite component 1600. FIG. 17 is a cross-sectional view taken along the alternate long and short dash line in FIG. An optical filter 1603 is provided on a waveguide substrate 1601 in which Y-shaped waveguides 1602a, 1602b, and 1602c made of a core material are formed on a clad material. By making this optical filter have the characteristics shown in FIG. 3, an optical composite component 1600 having both functions of an optical demultiplexer / multiplexer and an optical branch / coupler is realized.

(Embodiment 2)
In the optical transmission system of the first embodiment, the light emitting elements 401 of the electrical / optical converters 111a, 111b, and 111c transmit optical signals having different wavelengths λb3, λb2, and λb1, and sequentially optical demultiplexers / multiplexers. The combined optical signal is converted into an electrical signal by the single optical / electrical conversion unit 109 of the optical transmission / reception base unit 102. In this way, the combined optical signal is converted into an electric signal when it is used in a mobile communication base station or the like, in some cases, it is not necessary to separate the signals from the plurality of antennas 117a, 117b, and 117c. Because. The reason why different wavelengths are used is to reduce loss by using an optical demultiplexer / multiplexer when combining optical signals. However, if the loss in combining optical signals is not a problem because the transmission distance is short, for example, the wavelengths λb3, λb2, and λb1 can be set to close wavelengths to perform optical coupling.

  FIG. 18 is a configuration diagram of an optical composite component 1800 suitable for use in the electrical / optical converters 111a, 111b, and 111c in such a case. The configuration of the optical transmission system in the present embodiment is the same as that in FIG. The configuration of the optical composite component 1800 is similar to that of the optical composite component 200 used in the optical / electrical converter 113a in the first embodiment. The difference from the optical composite component 200 is that the light receiving element 205 is replaced with a light emitting element 1805 and the optical filter 203 is replaced with an optical filter 1803 having different characteristics. The characteristic of the optical filter 1803 is shown in FIG. Further, an example of the wavelength arrangement of the optical signals λb3, λb2, λb1, and λa in the present embodiment is also indicated by a broken line in FIG. The optical signals λb3, λb2, and λb1 are arranged closer to each other than in the first embodiment. However, when the synthesized signal is electrically converted, an optical frequency difference wider than the electrical signal frequency band may be provided to prevent beat noise having a frequency equal to the optical frequency difference of each wavelength from appearing in the electrical signal frequency band. desirable. This optical composite component 1800 also has a characteristic of the optical filter 1803 that transmits a part of light in a specific frequency band near λb1, λb2, and λb3, and reflects other light in a specific wavelength range. At the same time, it is a unique configuration of the present invention that light in a wavelength range away from a specific wavelength range in the vicinity of λb1, λb2, and λb3 has a characteristic of reflecting almost 100%. Corresponding to the symbols A and B attached to the optical fibers 202a and 202b of the optical composite part 1800, the optical composite parts 1800 are used by being connected to the optical fibers attached with A and B in FIG.

  According to this configuration, the characteristics of the optical filter 1803 with respect to the light in the specific frequency band are transmitted through a part thereof, and reflect other light in the specific wavelength band, and away from the specific wavelength band. The optical composite component 1800 having the functions of an optical demultiplexing / multiplexing device, an optical branching / combining device, and a light emitting element module can be realized with a simple configuration by reflecting light in the wavelength range to almost 100%.

(Embodiment 3)
FIG. 20 is a configuration diagram of the optical transmission system according to the third embodiment of the present invention. The configuration is similar to that of the first embodiment except that an optical demultiplexer / multiplexer 2007 that demultiplexes / multiplexes four wavelengths λa, λb1, λb2, and λb3 is added to the optical transmission / reception master unit 2002. The optical / electrical converters 2009a, 2009b, 2009c, and optical receiver circuits 2010a, 2010b, 2010c are provided corresponding to the wavelengths λb1, λb2, λb3. The optical composite component 200 is used for the optical / electrical converters 113a, 113b, and 113c of the optical transceivers 103a, 103b, and 103c, as in the first embodiment. In the first embodiment, the configuration in the case where it is not necessary to separate the signals from the plurality of antennas 117a, 117b, and 117c is shown. However, in this embodiment, the signals from the plurality of antennas 117a, 117b, and 117c are used. When the signals need to be separated, the respective signals can be output from the optical receiving circuits 2010a, 2010b, and 2010c.

  Even in such a configuration, the optical composite component 200 is used for the optical transceivers 103a, 103b, and 103c, and these are cascaded by one main system optical fiber 104a, 104b, and 104c. 2002 and a plurality of optical transceivers 103a, 103b, and 103c can transmit optical signals bidirectionally by wavelength multiplexing using only one optical fiber.

(Embodiment 4)
FIG. 21 is a configuration diagram of the optical transmission system according to the fourth embodiment of the present invention. In FIG. 21, the optical transmission system 2101 is different from the optical transmission system 101 according to the first embodiment shown in FIG. 1 in the following points. First, the optical transmission / reception master unit 2102 and a plurality of optical transmission / reception slave units 2103a, 2103b, 2103c are cascade-connected by a single loop main system optical fiber 104a, 104b, 104c, 104d. The optical transmission / reception master unit 2102 has no optical demultiplexer, and the electrical / optical conversion unit 105 and the optical / electrical conversion unit 109 are directly connected to the main system optical fibers 104d and 104a. The optical / electrical converters 2113a, 2113b, 2113c of the optical transceivers 2103a, 2103b, 2103c are different from the optical / electrical converters 113a, 113b, 113c of the optical transmission system 101. Other than the above, the optical transmission system 101 is the same.

  Next, the optical / electrical converters 2113a, 2113b, and 2113c will be described. Since the optical / electrical converters 2113a, 2113b, and 2113c have the same configuration, the optical / electrical converter 2113b will be described as an example here. FIG. 22 is a configuration diagram of the optical / electrical converter 2113b. The optical / electrical converter 2113b also uses the optical composite component 200 in the same manner as the optical / electrical converter 113a in FIG. What is different from the optical / electrical converter 113a is the connection of the optical fibers 202a and 202b, where B and C shown in FIG. 22 are connected so as to correspond to B and C in FIG. That is, contrary to the first embodiment, the optical fiber 202a is connected to the main system optical fiber 104c, and the optical fiber 202b is connected to the main system optical fiber 104b. The optical filter 203 has a characteristic that, for example, in the optical / electrical converter 2113b, as shown in FIG. 23, the reflectance is about 50% and the transmittance is about 50% within a specific wavelength region near the wavelength λa. In the wavelength region far from the region, the reflection is almost 100%. The characteristics of the optical filter 203 are desirably changed by the optical transceivers 103a, 103b, and 103c, as in the first embodiment. However, in this embodiment, the transmittance and the reflectance in a specific wavelength range are set as optical characteristics. It is desirable to set the transmission / reception slave unit 103a to about 100% and 0% and the optical transmission / reception slave unit 103c to about 33% and 67%. That is, the optical filter 203 is replaced with the optical transceiver unit 103a and the optical transceiver unit 103c as compared with the first embodiment. As a result, the optical signal having the wavelength λa is almost equally distributed to the three optical transceiver units.

  With this configuration, the optical signals from the optical transceiver units 103 a, 103 b, and 103 c to the optical transceiver base unit 2102 are sequentially optically multiplexed, as in the first embodiment, and the optical / electrical conversion unit 109 of the optical transceiver base unit 2102. Is converted into an electrical signal. On the other hand, the optical signals from the optical transmission / reception master unit 2102 to the optical transmission / reception slave units 103a, 103b, 103c are in the order of the optical transmission / reception slave units 103c, 103b, 103a from the main system optical fiber 104d (the reverse order of the first embodiment) ) And converted into electrical signals by the respective optical / electrical converters 2113c, 2113b, 2113a.

  As described above, according to the present embodiment, the optical composite component 200 is used for the optical transceivers 2103a, 2103b, and 2103c, and these are formed by a single loop-shaped main system optical fiber 104a, 104b, 104c, and 104d. With a simple configuration of cascade connection, the optical transmission / reception master unit 2102 and the plurality of optical transmission / reception slave units 103a, 103b, 103c can transmit optical signals by wavelength multiplexing using only one optical fiber. is there. Further, as compared with the first embodiment, the optical transmission / reception master unit 2102 does not require an optical demultiplexer and can be configured simply.

(Embodiment 5)
FIG. 24 is a configuration diagram of the optical transmission system according to the fifth embodiment of the present invention. The optical transmission system 2401 has a configuration similar to that of the optical transmission system 2001 in Embodiment 3 shown in FIG. The optical transmission system 2401 is different from the optical transmission system 2001 as follows. First, the optical transmission / reception master unit 2402 of the optical transmission system 2401 replaces the optical / electric conversion units 2009a, 2009b, 2009c and the optical reception circuits 2010a, 2010b, 2010c used in the optical transmission / reception master unit 2002 of the optical transmission system 2001. In addition, the optical / electrical converters 2409a, 2409b, and 2409c are connected to the optical transmission circuits 2410a, 2410b, and 2410c. That is, the optical transmission / reception master unit 2402 of the optical transmission system 2401 combines the optical signals of the four wavelengths of λa, λb1, λb2, and λb3 by the optical demultiplexer / multiplexer 2007 and sends it out. Another difference is that the optical transceivers 2403a, 2403b, and 2403c of the optical transmission system 2401 use the electrical / optical converters 111a, 111b, and 103c used in the optical transceivers 103a, 103b, and 103c of the optical transmission system 2001. Instead of the 111c and the optical transmission circuits 112a, 112b, and 112c, the electrical / optical conversion units 2411a, 2411b, and 2411c and the optical transmission circuits 2412a, 2412b, and 2412c are connected. The electrical / optical conversion units 2411a, 2411b, and 2411c have the same configuration, and the electrical / optical conversion unit 2411a has the configuration illustrated in FIG. That is, the electrical / optical conversion unit 2411a demultiplexes the optical signals having the wavelengths λa, λb1, and λb2 and the optical signal having the wavelength λb3 by the optical demultiplexer / multiplexer 2501, and only the optical signal having the wavelength λb3 is received by the light receiving element 2502. Thus, the electric signal is converted into an electric signal. The electrical / optical conversion units 2411b and 2411c have the same configuration, but the characteristics of the optical demultiplexer / multiplexer 2501 are different. Only the optical signals having wavelengths λb1 and λb2 are demultiplexed and converted into electrical signals by the light receiving element 2502. Convert. The optical transmission system 2401 other than the above has the same configuration as the optical transmission system 2001. For example, the optical composite component 200 shown in FIG. 2 is used for the optical / electrical converters 113a, 113b, and 113c of the optical transceivers 2403a, 2403b, and 2403c.

  That is, in the optical transmission system 2001, the signal of the wavelength λa and the signals of the wavelengths λb1, λb2, and λb3 are frequency-multiplexed in opposite directions, but in the optical transmission system 2401, the signal of the wavelength λa and the wavelengths λb1, λb2, The signal of λb3 is frequency-multiplexed in the same direction. With this configuration, the optical transmission system 2401 uses different optical signals from the optical transmission / reception master unit 2402 to the plurality of optical transmission / reception slave units 2403a, 2403b, and 2403c using one system of optical fiber. (Wavelengths λb1, λb2, λb3) can be transmitted and at the same time, the same optical signal (wavelength λa) can be distributed and transmitted.

  For example, such an optical transmission system 2401 uses a single optical fiber to distribute different data signals to a plurality of homes to personal computers 2417a, 2417b, and 2417c, and at the same time receives a video signal for broadcasting using the same optical fiber. This can be used when broadcasting to 2419a, 2419b, and 2419c.

  As described above, according to this embodiment, the optical / electrical converters 113a, 113b, and 113c of the optical transceivers 2403a, 2403b, and 2403c cascade-connected to the optical transmission base unit 2402 through a single optical fiber. By using the optical composite component 200, it is possible to multiplex transmission of different optical signals to a plurality of optical transceivers 2403a, 2403b, 2403c and broadcast distribution transmission of the same optical signal with a simple configuration. is there.

  In this embodiment only, the video signal and data signal transmission system is used as an application example, and the mobile communication system is used as an application example in the first to fourth embodiments. Regardless of applications such as telecommunications systems, video signal transmission systems, data signal transmission systems, and signal forms such as analog signals and digital signals, optical signals of a specific wavelength are optically demultiplexed / multiplexed, and at the same time, optical branching / combining It is clear that the present invention exhibits a specific effect in an optical transmission system that needs to be performed.

  The optical composite part according to the present invention and the optical transmission system using the same can realize an optical composite part having both the function of an optical demultiplexer / multiplexer and the function of an optical branch / coupler. It has an effect that only an optical signal having a wavelength within a specific wavelength range can be branched / combined with a simple configuration, and is useful as an application such as an optical transmission system for wavelength-multiplexing transmission of a plurality of optical signals.

Configuration diagram of optical transmission system according to Embodiment 1 of the present invention Configuration diagram of optical composite component in Embodiment 1 of the present invention The graph showing the characteristic of the optical filter used for the optical composite component in Embodiment 1 of this invention Configuration diagram of an electrical / optical conversion unit used in the optical transmission system in Embodiment 1 of the present invention Sectional drawing which shows the structural example of the optical filter used for the optical composite component in Embodiment 1 of this invention. The block diagram which shows the structural example by the conventional optical component equivalent to the function of the optical composite component in Embodiment 1 of this invention Sectional drawing which shows the other structural example of the optical filter used for the optical composite component in Embodiment 1 of this invention. Sectional drawing which shows the other structural example of the optical filter used for the optical composite component in Embodiment 1 of this invention. Configuration diagram of another optical composite component in Embodiment 1 of the present invention Configuration diagram of another optical composite component in Embodiment 1 of the present invention Configuration diagram of another optical composite component in Embodiment 1 of the present invention Configuration diagram of another optical composite component in Embodiment 1 of the present invention The graph showing the characteristic of the optical filter used for the other optical composite component in Embodiment 1 of this invention Configuration diagram of another optical composite component in Embodiment 1 of the present invention Configuration diagram of another optical composite component in Embodiment 1 of the present invention Configuration diagram of another optical composite component in Embodiment 1 of the present invention Sectional drawing of the other optical composite component in Embodiment 1 of this invention Configuration diagram of optical composite component in Embodiment 2 of the present invention The graph showing the characteristic of the optical filter used for the optical composite component in Embodiment 2 of this invention Configuration diagram of optical transmission system according to Embodiment 3 of the present invention Configuration diagram of optical transmission system according to Embodiment 4 of the present invention Configuration diagram of optical composite component used for optical transmission system in Embodiment 4 of the present invention Graph showing the characteristics of the optical filter used for the optical composite component in Embodiment 4 of the present invention Configuration diagram of optical transmission system according to Embodiment 5 of the present invention Configuration diagram of optical / electrical converter used in optical transmission system in embodiment 5 of the present invention Configuration of conventional optical transmission system

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Optical transmission system 102 Optical transmission / reception main | base station 103a, 103b, 103c Optical transmission / reception subunit | mobile_unit 104a, 104b, 104c Main system optical fiber 105 Electrical / optical conversion part 107 Optical demultiplexing / multiplexing unit 109 Optical / electrical conversion part 111a, 111b , 111c Electrical / optical converters 113a, 113b, 113c Optical / electrical converters 115a, 115b, 115c Optical fiber 200 Optical composite component 201, 204 Refractive index distribution type rod lens 202a, 202b Optical fiber 203 Optical filter 205 Light receiving element 205a Light receiving Light-receiving surface of element 501 Transparent substrate 502 Interference film filter by thin film multilayer 701 Transparent substrate 702 Interference film filter by thin film multilayer 703 Half mirror layer 801,804 Transparent substrate 802 Interference film filter by thin film multilayer 803 Half Layer 900 optical composite component 901, 904 convex lens 1000 optical composite component 1004a, 1004b convex lens 1100 optical composite component 1102, 1103 optical fiber 1104 light receiving element module 1200 optical composite component 1203 optical filter 1400 optical composite component 1401 lens 1500 optical composite component 1502a, 1502b Optical fiber 1503 Optical filter 1505 Light receiving element 1600 Optical composite part 1601 Waveguide substrate 1602a, 1602b, 1602c Waveguide 1603 Optical filter 1800 Optical composite part 1803 Optical filter 1805 Light emitting element 2001 Optical transmission system 2002 Optical transmission / reception master unit 2007 Optical demultiplexing / Mixer 2009a, 2009b, 2009c Optical / electrical converter 2101 Optical transmission system 104d Optical fiber 2102 Optical transmission / reception master unit 2113a, 2113b, 2113c Optical / electrical conversion unit 2401 Optical transmission system 2402 Optical transmission / reception master unit 2403a, 2403b, 2403c Optical transmission / reception slave unit 2409a, 2409b, 2409c Optical / electrical conversion unit 2411a, 2411b, 2411c Electrical / optical Conversion unit

Claims (27)

An optical filter is disposed on the first optical path at an angle other than a right angle to the first optical path, and a second optical path is provided at a position that is a reflection position from the first optical path with respect to the optical filter, An optical composite component having a demultiplexing characteristic, wherein a third optical path is provided at a position that is a transmission position from the first optical path with respect to the optical filter, wherein the optical filter is light in a specific wavelength range. An optical composite component characterized by reflecting a part of the light and transmitting another part of the light in the specific wavelength region and light of a wavelength outside the specific wavelength region. From the first, second, and third optical fibers, the input / output ends of the first, second, and third optical fibers are disposed near the focal planes of the first, second, and third lenses, respectively. Is converted into first, second, and third substantially parallel light paths, or the first, second, and third substantially parallel light paths are converted into incident light to the first, second, and third optical fibers. The optical composite component according to claim 1, wherein the first, second, and third optical paths in claim 1 are the first, second, and third substantially parallel optical paths. The input / output ends of the first and second optical fibers are arranged near one of the two focal planes of the first lens, and the first and second optical fibers are substantially parallel to each other. When the light is emitted from the first optical fiber, a part of the light converted into substantially parallel light by the first lens is reflected and condensed by the first lens, and the light is condensed by the first lens. An optical filter is disposed in the vicinity of another focal plane of the first lens at an angle incident on the second optical fiber, and the optical filter out of the light converted into substantially parallel light by the first lens An optical composite having a demultiplexing characteristic, wherein a second lens is provided in the transmitted optical path, and a third optical fiber is provided at a position where the second lens is coupled with light condensed near the focal plane by the second lens. A part of the light in a specific wavelength range. Shines light composite component and having other and a portion of the specific wavelength range of light, the properties of transmitting light of a wavelength of said specific wavelength outside. The optical composite component according to claim 1, wherein a light receiving element is provided in the second optical path. The optical composite component according to claim 2 or 3, wherein the second optical fiber is replaced with a light receiving element provided at the same position as an optical fiber entrance / exit end face position. The optical composite component according to claim 1, wherein a light emitting element is provided in the second optical path. 4. The optical composite component according to claim 2, wherein the second optical fiber is replaced with a light emitting element provided at the same position as an optical fiber entrance / exit end face position. The optical composite component according to any one of claims 1 to 7, wherein the optical filter has a reflectance of light in the specific wavelength range of 60% or less. Claims wherein the optical filter is replaced with an optical filter having a characteristic of transmitting a part of light in a specific wavelength region and reflecting another part of the light in the specific wavelength region and light having a wavelength outside the specific wavelength region. Item 1. The optical composite component according to Item 1. Claims wherein the optical filter is replaced with an optical filter having a characteristic of transmitting a part of light in a specific wavelength region and reflecting another part of the light in the specific wavelength region and light having a wavelength outside the specific wavelength region. The optical composite component according to claim 2 or claim 3. The optical composite component according to claim 9, wherein a light receiving element is provided in the third optical path. The optical composite component according to claim 10, wherein the third optical fiber is replaced with a light receiving element provided at an optical fiber entrance / exit end face position. The optical filter is replaced with an optical filter having a characteristic of transmitting a part of light in a specific wavelength range, reflecting another part of the light in the specific wavelength range, and light having a wavelength outside the specific wavelength range, The third optical fiber is replaced with a light receiving element provided at the position of the optical fiber input / output end face, and the distance between the centers of the input and output end faces of the first and second optical fibers arranged substantially in parallel is the light receiving element. The optical composite component according to claim 3, wherein the optical composite component is wider than a maximum width of a light receiving surface range having a light receiving sensitivity of 5. The optical composite component according to claim 9, wherein a light emitting element is provided in the third optical path. The optical composite component according to claim 10, wherein the third optical fiber is replaced with a light emitting element provided at an optical fiber entrance / exit end face position. The optical composite component according to any one of claims 9 to 15, wherein the optical filter has a light transmittance of 60% or less in the specific wavelength region. The optical composite component according to any one of claims 1 to 16, wherein the optical filter is formed of an interference film filter using a thin film multilayer. The optical filter transmits a light in a specific wavelength range and transmits a specific wavelength range transmission filter that reflects light in a wavelength other than the specific wavelength range, and transmits a part of the light in all the wavelength ranges to be used. The optical composite component according to any one of claims 9 to 15, wherein a half mirror layer that reflects the light is overlapped. The optical filter is laminated on a specific wavelength band transmission filter that transmits light of a specific wavelength band and reflects light of a wavelength other than the specific wavelength band, and transmits a part of the light of all the wavelength bands used, The optical composite component according to any one of claims 9 to 15, wherein a half mirror layer that reflects other light is formed. The optical composite component according to claim 18 or 19, wherein the optical filter is installed in a direction in which light other than the specific wavelength region enters from a specific wavelength region transmission filter side of the optical filter. An optical transmission system in which a plurality of electrical / optical conversion units or optical / electrical conversion units are connected in series through a main optical fiber, and each of the plurality of electrical / optical conversion units or optical / electrical conversion units is claimed. 21. An optical transmission system using the optical composite component according to any one of claims 1 to 20, for branching or coupling an optical signal having a wavelength within the specific wavelength range transmitted by a main optical fiber. . The optical transmission system according to claim 21, wherein the main system optical fiber wavelength-multiplexes an optical signal having a wavelength outside the specific wavelength range together with an optical signal having a wavelength within the specific wavelength range. 4. An optical transmission system in which a plurality of optical transceiver units are sequentially connected in cascade with a main system optical fiber, wherein each of the plurality of optical transceiver units is the optical composite component according to claim 2 or claim 3. A light receiving element is connected to the second optical fiber to form an optical / electrical change part, or a light receiving element is connected to the third optical fiber of the optical composite component according to claim 10 to connect the optical / electrical change part. The specified signal transmitted by the main system optical fiber by configuring an optical / electrical converter using an optical composite part having the light receiving element according to claim 4, claim 5, or claim 11 to 13. The optical signal having a wavelength within the wavelength range is branched and received, and each of the plurality of optical transceivers transmits an optical signal having a different wavelength outside the specific wavelength range to the electrical / optical conversion unit that transmits the optical signal having a different wavelength outside the specific wavelength range. of The optical transmission system by connecting the optical multiplexer, for transmitting the different wavelength optical signal of the specific wavelength outside the main line optical fibers corresponding to the Re different wavelengths respectively. Opposite the plurality of optical transceiver units, an optical transmission / reception master unit is connected to the main optical fiber, and bidirectional optical signal transmission is performed between the plurality of optical transceiver units and the optical transmission / reception master OLE_LINK1 unit OLE_LINK1. In the optical transmission system, the optical transmission / reception master unit demultiplexes and receives each of optical signals of different wavelengths outside the specific wavelength range transmitted by the electrical / optical conversion units of the plurality of optical transmission / reception slave units. The optical transmission system according to claim 23, further comprising: an optical / electrical conversion unit; and an electrical / optical conversion unit that transmits an optical signal having a wavelength within the specific wavelength range. Optical transmission in which an optical transmission / reception master unit is connected to the main optical fiber so as to face the plurality of optical transmission / reception slave units, and bidirectional optical signal transmission is performed between the plurality of optical transmission / reception slave units and the optical transmission / reception master unit The optical transmission / reception master unit is configured to receive optical signals having a plurality of wavelengths out of the optical signals having different wavelengths outside the specific wavelength range transmitted by the electrical / optical conversion units of the plurality of optical transmission / reception slave units. 24. The optical transmission system according to claim 23, further comprising: an optical / electrical conversion unit that performs an optical / electrical conversion unit that transmits an optical signal having a wavelength within the specific wavelength range. An optical communication system in which an optical transmission / reception master unit and the plurality of optical transmission / reception slave units are cascade-connected with a loop-shaped main system optical fiber, wherein the optical transmission / reception master unit transmits an optical signal within the specific wavelength range. 24. The optical transmission system according to claim 23, wherein an optical converter, a plurality of optical transceivers, and an optical / electrical converter of the optical transceiver that receives an optical signal outside the specific wavelength range are connected in cascade. An optical transmission system in which a plurality of optical transceiver units are connected in cascade with a main system optical fiber, each of the plurality of optical transceiver units,
A light receiving element is connected to the second optical fiber of the optical composite component according to claim 2 or claim 3 to form a first optical / electrical change part, or the optical composite component according to claim 10 A light receiving element is connected to the third optical fiber to form a first light / electricity changing portion, or an optical composite part having the light receiving element according to claim 4 or claim 5 or claim 11 to claim 13. Using the first optical / electrical conversion unit to branch and receive an optical signal having a wavelength within the specific wavelength range transmitted by the main optical fiber;
Each of the plurality of optical transceivers includes an optical multiplexer / demultiplexer that demultiplexes optical signals having different wavelengths outside the specific wavelength range, and an electrical signal that is an optical signal demultiplexed by the optical multiplexer / demultiplexer. An optical transmission system, wherein an optical signal outside the characteristic wavelength range is received by a second optical / electrical converter comprising a light receiving element for conversion.

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