JP5670150B2 - Optical amplification module and method for replacing excitation light source of optical amplification module - Google Patents

Description

  The present invention relates to an optical amplification module and a method for replacing an excitation light source of the optical amplification module.

  Patent Document 1 describes a technique related to an optical amplifier employed in a transmission method using an optical fiber for optical amplification that directly amplifies an optical signal in a long-distance optical fiber communication system. This optical amplifier includes a rare earth-doped optical fiber as an optical fiber for optical amplification, and includes two pumping light sources for supplying pumping light to the optical fiber. When one excitation light source cannot output excitation light with sufficient intensity due to deterioration over time or the like, the other excitation light source supplements the excitation light.

JP 2005-64528 A

  According to the configuration described in Patent Document 1, even if the excitation light source deteriorates, it can be switched to an alternative excitation light source without stopping the communication system. However, in a large-scale optical communication system such as FTTH (Fiber To The Home), for example, a transmission device in which a large number of optical amplifiers are mounted is arranged on the station side. In the transmission apparatus, a large number of optical amplification modules are mounted in one rack.

  When one pumping light source fails in such a transmission apparatus, the method for replacing the pumping light source becomes a problem. That is, even if it is possible to switch to an alternative pumping light source by the configuration described in Patent Document 1, in order to replace a failed pumping light source with a normal one, the operation of the optical amplification module is stopped and the rack is Need to be taken out of. However, when the operation of the optical amplification module is stopped, each terminal connected to the optical communication system cannot communicate, and many terminals are affected. As one of the methods for solving such a problem, for example, two transmission systems are arranged in a redundant configuration, and when one pumping light source of one system fails, the other system is operated, and the pumping light source is set between them. A method of replacement is conceivable. However, such a method doubles the size of the transmission system, increases the size of the transmission device, and increases the manufacturing cost.

  The present invention has been made in view of such problems, and provides an optical amplification module capable of exchanging an excitation light source while suppressing the scale of a transmission apparatus, and an excitation light source replacement method for the optical amplification module The purpose is to do.

  In order to solve the above-described problems, a first optical amplification module according to the present invention includes an excitation light source that generates excitation light and signal light input from one end upon receiving excitation light at at least one of the one end and the other end. A substrate on which an optical amplification optical fiber to be amplified is mounted, a first signal light input port optically coupled to the other end of the optical amplification optical fiber and receiving amplified signal light, and a first signal And an optical unit that is optically coupled to the optical input port and outputs the amplified signal light to the outside. The optical unit is detachably attached to the substrate. A second signal light input port optically coupled to the output port is further provided, and the second signal light input port is a substitute for the amplified signal light from a signal source provided outside the substrate. Emergency signal light is input And features.

  The second optical amplification module according to the present invention includes a substrate on which a first excitation light source that generates excitation light is mounted, and signal light that is input from one end by receiving excitation light at least one of the one end and the other end. An optical fiber for amplifying the light, a first pumping light input port optically coupled to at least one of the one end and the other end of the optical amplifying optical fiber and receiving pumping light from the first pumping light source, and light An optical unit having a signal light output port optically coupled to the other end of the amplification optical fiber and outputting the amplified signal light to the outside, and detachably attached to the substrate. Further includes a second pumping light input port optically coupled to at least one of the one end and the other end of the optical amplification optical fiber, and the second pumping light input port is provided outside the substrate. From the second excitation light source Wherein the emergency pump light as a light alternative is input.

  The first and second optical amplification modules described above have a light intensity detection means for detecting the intensity of the amplified signal light and the intensity of the amplified signal light based on the detection result of the light intensity detection means. And a control unit that controls the intensity of the excitation light of the first excitation light source so as to approach the distance.

  The substrate replacement method of the first optical amplification module according to the present invention includes a first excitation light source that generates excitation light and signal light input from one end upon receiving excitation light at at least one of the one end and the other end. A substrate on which an optical fiber for amplification to be amplified is mounted, a signal light input port for receiving amplified signal light from the optical fiber for optical amplification, a signal light output port for outputting amplified signal light to the outside, and signal light A method for exchanging a substrate of an optical amplifying module comprising a second signal light input port optically coupled to an output port and an optical unit detachably attached to the substrate, An emergency input step for inputting emergency signal light as a substitute for amplified signal light from a signal source provided outside the substrate, and output of excitation light from the first excitation light source. Stopped An excitation light stop step, a separation step for removing the optical unit from the substrate, a mounting step for attaching the optical unit to the replacement substrate, and an output of the excitation light from the first excitation light source mounted on the replacement substrate It includes a pumping light output step and a removal step of removing the signal source from the second signal light input port.

  Further, the substrate replacement method for the second optical amplification module according to the present invention includes a substrate on which the first excitation light source for generating excitation light is mounted and at least one of the one end and the other end receiving the excitation light and inputting from one end. An optical fiber for amplifying the amplified signal light, a first pumping light input port for receiving the pumping light from the first pumping light source and providing the pumping light to the optical fiber for optical amplification, and the amplified signal light A signal light output port for output to the outside, and a second excitation light input port optically coupled to at least one of one end and the other end of the optical fiber for optical amplification, are detachably attached to the substrate. A method of exchanging a substrate of an optical amplifying module provided with an optical unit, wherein the second pumping light input port is a substitute for pumping light from a second pumping light source provided outside the substrate. Non-exciting light input An input step, an excitation light stop step for stopping the output of the excitation light from the first excitation light source, a separation step for removing the optical unit from the substrate, a mounting step for attaching the optical unit to the replacement substrate, and a replacement A pumping light output step for outputting pumping light from the first pumping light source mounted on the substrate, and a removal step of removing the second pumping light source from the second pumping light input port.

  According to the light amplification module and the substrate replacement method of the light amplification module according to the present invention, the excitation light source can be replaced while suppressing the scale of the transmission device.

FIG. 1 is a diagram showing a configuration of an optical amplification module according to the first embodiment of the present invention. FIG. 2 is a plan view showing the appearance of the optical amplification module. FIG. 3 is a flowchart showing the steps of this exchange method. 4 to 7 are perspective views for explaining some steps of the replacement method. 4 to 7 are perspective views for explaining some steps of the replacement method. 4 to 7 are perspective views for explaining some steps of the replacement method. 4 to 7 are perspective views for explaining some steps of the replacement method. FIG. 8 is a diagram illustrating a configuration of the optical amplification module according to the first modification. FIG. 9 is a diagram illustrating a configuration of an optical amplification module according to a second modification. FIG. 10 is a diagram illustrating a configuration of an optical amplification module according to a third modification. FIG. 11 is a diagram illustrating a configuration of an optical amplification module according to a fourth modification. FIG. 12 is a diagram showing a configuration of an optical amplification module according to the second embodiment of the present invention. FIG. 13 is a flowchart showing the steps of this exchange method. FIG. 14 is a diagram illustrating a configuration of an optical amplification module according to a fifth modification. FIG. 15 is a diagram illustrating a configuration of an optical amplification module according to a sixth modification. FIG. 16 is a diagram illustrating a configuration of an optical amplification module according to a seventh modification. FIG. 17 is a diagram illustrating a configuration of an optical amplification module according to an eighth modification.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of an optical amplification module and an optical amplification module substrate replacement method according to the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted.

(First embodiment)
FIG. 1 is a diagram showing a configuration of an optical amplification module 1A according to the first embodiment of the present invention. FIG. 2 is a plan view showing the appearance of the optical amplification module 1A. The optical amplification module 1A of this embodiment is an optical amplification module for FTTH, which directly amplifies transmission light output from a separately provided optical transmitter and outputs the amplified transmission light to a plurality of optical fibers. To do. The optical amplification module 1A is inserted and mounted in one slot of a housing (chassis) having a plurality of slots, for example. The housing has, for example, a wiring board disposed behind a plurality of slots, and a plurality of electrical connectors for mounting a plurality of optical amplification modules are mounted side by side on the wiring board. ing.

  As shown in FIGS. 1 and 2, the optical amplification module 1A includes a substrate 10A and an optical unit 20A. As shown in FIG. 2, the substrate 10A has a wiring substrate 10f on which electrical wiring is printed. As shown in FIG. 1, the substrate 10 </ b> A includes an optical amplification optical fiber 11, excitation light sources 12 and 13, photodiodes 14 a to 14 c, a signal light input port 16, a signal light output port 17, and a control unit 18. The optical fiber 11 for optical amplification, the excitation light source 12, and the photodiodes 14a to 14c are mounted on the wiring board 10f. Further, the signal light input port 16 and the signal light output port 17 are each preferably configured by optical connectors 16a and 17a shown in FIG.

  The signal light input port 16 is optically coupled to one end 11a of the optical fiber 11 for optical amplification via two optical couplers 19a and 19b. Signal light is input to the signal light input port 16 from an external signal source. Further, a photodiode 14a is optically coupled to the signal light input port 16 via an optical coupler 19a. The photodiode 14 a detects the intensity of the signal light input to the signal light input port 16.

  The optical fiber 11 for optical amplification is an optical fiber to which a rare earth element such as erbium is added. The optical fiber 11 for optical amplification receives the excitation light at one end 11a and the other end 11b, thereby amplifying the signal light input from the one end 11a and outputting from the other end 11b. Signal light is input from the signal light input port 16 to one end 11 a of the optical fiber 11 for optical amplification. Further, an excitation light source 12 is optically coupled to one end 11a of the optical fiber 11 for optical amplification via an optical coupler 19b. The excitation light source 12 includes a laser diode, and outputs excitation light to the optical fiber 11 for optical amplification. The other end 11b of the optical fiber 11 for optical amplification is optically coupled to the signal light output port 17 through optical couplers 19c and 19d. The other end 11b of the optical fiber 11 for optical amplification is optically coupled to the excitation light source 13 via an optical coupler 19c. The excitation light source 13 includes a laser diode, and outputs excitation light to the optical fiber 11 for optical amplification.

  The signal light output port 17 is optically coupled to the photodiode 14b via the optical coupler 19d. The photodiode 14b detects the intensity of the signal light reflected by the optical unit 20A. The photodiode 14 c is optically coupled to the signal light input port 15. The signal light input port 15 is optically coupled to the other end 11b of the optical amplification optical fiber 11 through an optical unit 20A described later, and the amplified signal light is input to the signal light input port 15. . The photodiode 14c is a light intensity detection means in the present embodiment, and detects the intensity of the amplified signal light output from the optical amplification optical fiber 11.

  The control unit 18 generates a control signal for controlling the intensity of the excitation light of the excitation light sources 12 and 13. The control unit 18 acquires an electrical signal related to the intensity of the amplified signal light from the photodiode 14c, and generates the control signal based on the detection signal so that the intensity of the amplified signal light approaches a predetermined value. .

  The optical unit 20A is attached to the substrate 10A by a fixing tool, for example, a screw 20a (see FIG. 2), and the screw 20a can be attached and detached freely, so that the optical unit 20A can be attached to and detached from the substrate 10A. . The optical unit 20A has a support plate 20b shown in FIG. 2, and components of the optical unit 20A described below are mounted on the back surface of the support plate 20b.

  As shown in FIG. 1, the optical unit 20 </ b> A includes signal light input ports 21 and 22, an optical splitter 23, and a plurality of signal light output ports 24. The signal light input port 21 is preferably configured by an optical connector 21a shown in FIG. The plurality of signal light output ports 24 are preferably configured by an optical connector 24a shown in FIG.

  The signal light input port 21 is a first signal light input port in the present embodiment, and is connected to the signal light output port 17 of the substrate 10A. The signal light input port 21 is optically coupled to the other end 11b of the optical amplification optical fiber 11 via the signal light output port 17, and receives the amplified signal light. The signal light input port 22 is a second signal light input port in the present embodiment. The signal light input port 22 receives signal light for emergency operation (hereinafter referred to as emergency signal light) from a signal source (not shown) provided outside the substrate 10A. The emergency signal light is an optical signal output from each of the plurality of signal light output ports 24 to each terminal as a substitute for the amplified signal light when the failed substrate 10A is replaced with a new substrate 10A.

  The optical splitter 23 has one input end 23a and a plurality of output ends 23b. The input end 23 a is optically coupled to both the signal light input ports 21 and 22 via the optical coupler 25, receives the amplified signal light from the signal light input port 21, and receives an emergency signal from the signal light input port 22. Receive signal light. The optical splitter 23 branches the signal light input to the input end 23a to a plurality of output ends 23b. Each of the plurality of output ends 23b is optically coupled to each of the plurality of signal light output ports 24, and the branched signal light is output from the plurality of signal light output ports 24 to the outside.

  A signal light output port 26 is further coupled to the signal light input ports 21 and 22 via an optical coupler 25. The signal light output port 26 is a port connected to the signal light input port 15 of the substrate 10 </ b> A, the amplified signal light input from the signal light input port 21, and the emergency signal input from the signal light input port 22. Signal light is provided to the signal light input port 15.

  If any of the pumping light sources 12 and 13 of the optical amplification module 1A having the above configuration fails, it is necessary to replace the pumping light source with a new one. At this time, in this embodiment, the substrate 10A including the excitation light sources 12 and 13 is replaced with a new substrate 10A. Hereinafter, the replacement method will be described. FIG. 3 is a flowchart showing the steps of this exchange method. 4 to 7 are perspective views for explaining some steps of the replacement method.

  In this method, first, an external signal source for generating emergency signal light is prepared (step S11). Next, this external signal source is connected to the signal light input port 22, and emergency signal light is input from the external signal source to the signal light input port 22 (step S12: emergency input step). Then, the intensity of the emergency signal light from the external signal source is gradually increased to approach the first predetermined value (step S13). At this time, the amplified optical signal output from the optical amplification optical fiber 11 and the emergency signal light are superimposed, and the light intensity thereof is detected by the photodiode 14c. Further, the control unit 18 controls the excitation light intensity of the excitation light sources 12 and 13 so that the detection result in the photodiode 14c approaches a certain value. Therefore, when the intensity of the emergency signal light increases, the excitation light intensity decreases accordingly. During this time, emergency signal light is output from the plurality of signal light output ports 24.

  Thereafter, the intensity of the emergency signal light is gradually increased until the excitation light intensity falls below the second predetermined value. If it can be confirmed that the excitation light intensity is lower than the second predetermined value (that is, the output of the excitation light from the excitation light sources 12 and 13 is stopped) (step S14, excitation light stop step), FIG. As shown in FIG. 4, the optical amplification module 1A is pulled out from the housing 100 (step S15). Thereby, the electrical connection between the substrate 10A of the optical amplification module 1A and the wiring substrate on the housing 100 side is released. Subsequently, as shown in FIG. 5, the screw 20a is removed from the substrate 10A. Then, as shown in FIG. 6, the optical unit 20A is detached from the substrate 10A (step S16: separation step). At this time, the coupled state between the signal light output port 17 of the substrate 10A and the signal light input port 21 of the optical unit 20A is released.

  Subsequently, as shown in FIG. 7, the substrate 10A is completely extracted from the housing 100 (step S17). Then, the replacement substrate 10A is inserted halfway through the slot of the housing 100 (step S18), and the optical unit 20A is attached to the replacement substrate 10A with the screw 20a (step S19: mounting step). Subsequently, the replacement substrate 10A is completely inserted into the housing 100, and the replacement substrate 10A and the wiring substrate of the housing 100 are electrically connected (step S20). As a result, the excitation light sources 12 and 13 can output excitation light in the replacement substrate 10A.

  Subsequently, the intensity of the emergency signal light provided from the external signal source is reduced (step S21). At this time, the control unit 18 of the replacement substrate 10A attempts to bring the detection intensity in the photodiode 14c close to a constant value, so that the intensity of the excitation light output from the excitation light sources 12 and 13 is increased (excitation light output step). ). Then, after confirming the alarm state of the optical amplification module 1A and the states of the excitation light sources 12 and 13 (step S22), the external signal source is removed from the signal light input port 22 (step S23: removal step). Through the above steps, the substrate 10A is exchanged without stopping the signal light output from the optical amplification module 1A to the outside.

  According to the optical amplification module 1A and the replacement method of the present embodiment, when the excitation light sources 12 and 13 break down, the excitation light sources 12 and 13 are switched without stopping the signal light output from the optical amplification module 1A to the outside. The board | substrate 10A containing can be replaced | exchanged. Further, since an external signal source is used to obtain emergency signal light, the optical amplification module 1A itself does not need to have an emergency signal system, and the size of the transmission apparatus can be kept small.

  In place of the optical coupler 25 that couples the signal light input ports 21 and 22 and the optical splitter 23, an optical switch may be provided. In this case, when the substrate 10 </ b> A is replaced, the coupling destination of the input end 23 a of the optical splitter 23 is switched from the signal light input port 21 to the signal light input port 22.

(First modification)
FIG. 8 is a diagram illustrating a configuration of an optical amplification module 1B according to the first modification. As shown in FIG. 8, the optical amplification module 1B includes a substrate 10B and an optical unit 20B. The substrate 10B includes an optical fiber 11 for optical amplification, excitation light sources 12 and 13, photodiodes 14a and 14c, a signal light input port 16, a signal light output port 17, and a control unit 18. Among these, the mutual coupling relationship of the signal light input port 16, the photodiode 14a, the excitation light source 12, and the one end 11a of the optical amplification optical fiber 11 is the same as that of the first embodiment. The coupling relationship between the pumping light source 13 and the other end 11b of the optical fiber 11 for optical amplification 11 is the same as that in the first embodiment.

  The other end 11b of the optical fiber 11 for optical amplification is optically coupled to the signal light output port 17 through two optical couplers 19c and 19e. The other end 11b of the optical amplifying optical fiber 11 is optically coupled to a photodiode 14c via an optical coupler 19e, and the photodiode 14c is an amplified signal light output from the optical amplifying optical fiber 11. Detect the intensity of.

  The optical unit 20B has the same configuration as the optical unit 20A of the first embodiment, except that the signal light output port 26 is not provided.

  The optical amplification module can be suitably used for the replacement method described in the first embodiment by including the configuration as in the present modification, and can exhibit the same effects as those in the first embodiment. .

(Second modification)
FIG. 9 is a diagram illustrating a configuration of an optical amplification module 1C according to the second modification. As shown in FIG. 9, the optical amplification module 1C includes a substrate 10C and an optical unit 20A. The substrate 10C has the same configuration as the substrate 10A of the first embodiment except that the substrate 10C does not have the excitation light source 13. The configuration of the optical unit 20A is the same as that of the first embodiment.

  Even in the case where the excitation light source is provided only on the one end 11a side of the optical fiber 11 for optical amplification as in this modification, the replacement method described in the first embodiment can be suitably performed. The same effect as the form can be achieved.

(Third Modification)
FIG. 10 is a diagram illustrating a configuration of an optical amplification module 1D according to the third modification. As shown in FIG. 10, the optical amplification module 1D includes a substrate 10D and an optical unit 20A. The substrate 10D has the same configuration as the substrate 10A of the first embodiment except that the substrate 10D does not have the excitation light source 12. The configuration of the optical unit 20A is the same as that of the first embodiment.

  Even in the case where the excitation light source is provided only on the other end 11b side of the optical amplifying optical fiber 11 as in this modification, the replacement method described in the first embodiment can be suitably performed. The same effects as the embodiment can be achieved.

(Fourth modification)
FIG. 11 is a diagram illustrating a configuration of an optical amplification module 1E according to a fourth modification. As shown in FIG. 11, the optical amplification module 1E includes a substrate 10E and an optical unit 20E. The board 10E of this modification has a connector 10g for inputting an electric signal, instead of the photodiode 14c of the first embodiment. The optical unit 20E includes a photodiode 27 in addition to the configuration of the optical unit 20A of the first embodiment. The photodiode 27 is coupled to the signal light input ports 21 and 22 via the optical coupler 25, and the amplified signal light input from the signal light input port 21 and the emergency input from the signal light input port 22. The light intensity of the signal light for use is detected. The photodiode 27 provides an electrical signal corresponding to the light intensity to the control unit 18 via the connector 10g.

  The control unit 18 generates a control signal for controlling the intensity of the excitation light of the excitation light sources 12 and 13 so that the electrical signal acquired from the photodiode 27 approaches a predetermined value.

  Even when the photodiode for detecting the signal light intensity is provided on the optical unit side as in this modification, the replacement method described in the first embodiment can be suitably performed. Similar effects can be obtained.

(Second Embodiment)
FIG. 12 is a diagram showing a configuration of an optical amplification module 1F according to the second embodiment of the present invention. As shown in FIG. 12, the optical amplification module 1F includes an optical unit 30A and a substrate 40A. Similarly to the first embodiment, the optical unit 30A is attached to the substrate 40A with screws, and the screws can be attached and detached, so that the optical unit 30A can be attached to and detached from the substrate 40A.

  As shown in FIG. 12, the optical unit 30A includes a signal light input port 31, an optical amplification optical fiber 32, an optical splitter 33, a plurality of signal light output ports 34, three pumping light input ports 35a, 35b and 35c. The substrate 40A includes excitation light sources 41 and 42, photodiodes 43a to 43c, and a control unit 44.

  The signal light input port 31 is coupled to a signal source (optical transmitter) disposed outside the optical amplification module 1F via an optical fiber, and receives signal light from the signal source. The excitation light input ports 35a and 35b are the first excitation light input ports in the present embodiment. The excitation light input ports 35a and 35b receive excitation light for normal operation (hereinafter referred to as normal excitation light) from the excitation light sources 41 and 42 (first excitation light source) mounted on the substrate 40A. The excitation light input port 35c is a second excitation light input port in the present embodiment. The excitation light input port 35c receives excitation light for emergency operation (hereinafter referred to as emergency excitation light) from an excitation light source (second excitation light source) provided outside the substrate 40A. The emergency excitation light is excitation light that is input to the optical unit 30A as an alternative to the normal excitation light when the failed substrate 40A is replaced with a new substrate 40A.

  The optical fiber 32 for optical amplification is an optical fiber to which a rare earth element such as erbium is added, and has one end 32a and the other end 32b. The one end 32a is optically coupled to the signal light input port 31 via two optical couplers 36a and 36b, and signal light is input to the one end 32a. One end 32a of the optical fiber 32 for optical amplification is optically coupled to the pumping light input port 35a via the optical coupler 36b, and normal pumping light is input to the one end 32a. The other end 32b of the optical fiber 32 for optical amplification is optically coupled to the input end 33a of the optical splitter 33 via two optical couplers 36c and 36d. The other end 32b is optically coupled to the pumping light input ports 35b and 35c via two optical couplers 36c and 36e, and normal pumping light and emergency pumping light are input to the other end 32b. Is done. The optical fiber 32 for optical amplification receives the excitation light at one end 32a and the other end 32b, thereby amplifying the signal light input from the one end 32a and outputting from the other end 32b.

  The optical splitter 33 has one input end 33a and a plurality of output ends 33b. The optical splitter 33 branches the amplified signal light input to the input end 33a to a plurality of output ends 33b. Each of the plurality of output ends 33b is optically coupled to each of the plurality of signal light output ports 34, and the branched amplified signal light is output from the plurality of signal light output ports 34 to the outside.

  A signal light input port 35d is coupled to the signal light input port 31 via an optical coupler 36a. A photodiode 43a mounted on the substrate 40A is optically coupled to the signal light input port 35d. The photodiode 43 a detects the intensity of the signal light input to the signal light input port 31. A signal light output port 35e is coupled to the other end 32b of the optical fiber 32 for optical amplification via an optical coupler 36d. A photodiode 43b mounted on the substrate 40A is optically coupled to the signal light output port 35e. The photodiode 43b detects the intensity of the amplified signal light output from the other end 32b. A reflected light intensity monitoring port 35f is coupled to the input end 33a of the optical splitter 33 via an optical coupler 36d. A photodiode 43c mounted on the substrate 40A is optically coupled to the reflected light intensity monitoring port 35f. The photodiode 43 c detects the intensity of the light reflected at the optical splitter 33 and the signal light output port 34.

  The substrate 40A has two pumping light output ports 45a and 45b and three signal light input ports 45c to 45e. The pumping light output ports 45a and 45b are respectively coupled to the pumping light sources 41 and 42, and provide pumping light to the pumping light input ports 35a and 35b of the optical unit 30A, respectively. Each of the signal light input ports 45c to 45e is coupled to each of the photodiodes 43a to 43c. Each of the signal light input ports 45c to 45e receives signal light or reflected light from the signal light output ports 35d and 35e and the reflected light intensity monitoring port 35f of the optical unit 30A, and these signal light or reflected light is received by the photodiode 43a. To 43c each.

  The control unit 44 generates a control signal for controlling the intensity of the excitation light from the excitation light sources 41 and 42. The control unit 44 acquires an electric signal related to the intensity of the amplified signal light from the photodiode 43b, and generates the control signal based on the detection signal so that the intensity of the amplified signal light approaches a predetermined value. .

  If any one of the excitation light sources 41 and 42 of the optical amplification module 1F having the above configuration fails, it is necessary to replace the excitation light source with a new one. At this time, in this embodiment, the substrate 40A including the excitation light sources 41 and 42 is replaced with a new substrate 40A. Hereinafter, the replacement method will be described. FIG. 13 is a flowchart showing the steps of this exchange method.

  In this method, first, an external excitation light source that generates emergency excitation light is prepared (step S31). Next, this external excitation light source is connected to the excitation light input port 35c, and emergency excitation light is input from the external excitation light source to the excitation light input port 35c (step S32: emergency input step). Then, the intensity of the emergency excitation light from the external excitation light source is gradually increased to approach the first predetermined value (step S33). At this time, the normal excitation light input from the excitation light sources 41 and 42 and the emergency excitation light input from the external excitation light source are superposed, and the signal light intensity amplified in accordance with these excitation lights is a photodiode. 43b. Further, the control unit 44 controls the excitation light intensity of the excitation light sources 41 and 42 so that the detection intensity in the photodiode 43b approaches a certain value. Therefore, when the intensity of the emergency excitation light increases, the intensity of the normal excitation light decreases accordingly.

  Thereafter, the intensity of the emergency excitation light is gradually increased until the intensity of the normal excitation light falls below the second predetermined value. If it can be confirmed that the intensity of the normal excitation light is below the second predetermined value (that is, the output of the excitation light from the excitation light sources 41 and 42 is stopped) (step S34, excitation light stop step). In the same manner as in FIG. 4, the optical amplification module 1F is pulled out from the housing (step S35). Thereby, the electrical connection between the substrate 40A of the optical amplification module 1F and the wiring substrate on the housing side is released. Subsequently, as in FIG. 5, the screw of the optical amplification module 1F is removed from the substrate 40A. Then, similarly to FIG. 6, the optical unit 30A is detached from the substrate 40A (step S36: separation step). At this time, the coupling state between the excitation light input ports 35a and 35b of the optical unit 30A and the excitation light output ports 45a and 45b of the substrate 40A, and the signal light output ports 35d and 35e of the optical unit 30A and the signal light input port of the substrate 40A The combined state with 45c and 45d is released.

  Subsequently, in the same manner as in FIG. 7, the substrate 40A is completely removed from the housing (step S37). Then, the replacement board 40A is inserted halfway through the slot of the housing (step S38), and the optical unit 30A is attached to the replacement board 40A with screws (step S39: mounting step). Subsequently, the replacement board 40A is completely inserted into the casing, and the replacement board 40A and the wiring board of the casing are electrically connected (step S40). As a result, the excitation light sources 41 and 42 can output excitation light on the replacement substrate 40A.

  Then, the intensity | strength of emergency excitation light provided from the external excitation light source is reduced (step S41). At this time, the control unit 44 of the replacement substrate 40A attempts to bring the detection intensity in the photodiode 43b closer to a constant value, so that the intensity of the excitation light output from the excitation light sources 41 and 42 is increased (excitation light output step). ). Then, after confirming the alarm state of the optical amplification module 1F and the states of the excitation light sources 41 and 42 (step S42), the external excitation light source is removed from the excitation light input port 35c (step S43: removal step). Through the above steps, the substrate 40A is replaced without stopping the signal light output from the optical amplification module 1F to the outside.

  According to the optical amplification module 1F and the replacement method of the present embodiment, when the excitation light sources 41 and 42 are out of order, the excitation light sources 41 and 42 are not stopped without stopping the signal light output from the optical amplification module 1F to the outside. The included substrate 40A can be replaced. Further, since an external pumping light source is used to obtain emergency pumping light, the optical amplification module 1F itself does not need to have an emergency signal system, and the size of the transmission device can be reduced.

  An optical switch may be provided instead of the optical coupler 36e that couples the pumping light input ports 35b and 35c and the other end 32b of the optical fiber 32 for optical amplification. In this case, when the substrate 40A is replaced, the coupling destination of the other end 32b of the optical fiber for optical amplification 32 is switched from the excitation light input port 35b to the excitation light input port 35c.

(Fifth modification)
FIG. 14 is a diagram illustrating a configuration of an optical amplification module 1G according to the fifth modification. As shown in FIG. 14, the optical amplification module 1G includes an optical unit 30B and a substrate 40A. The configuration of the substrate 40A is the same as that of the second embodiment. The optical unit 30B has the same configuration as the optical unit 30A of the second embodiment except for the following points. That is, the optical unit 30B of this modification has a pumping light input port 35g instead of the pumping light input port 35c of the second embodiment. The excitation light input port 35g is a port for receiving emergency excitation light from an external excitation light source. The pumping light input port 35g is optically coupled to the one end 32a of the optical fiber 32 for optical amplification through the optical coupler 36f together with the pumping light input port 35a. Therefore, in this modification, emergency pump light is input to the one end 32 a of the optical amplification optical fiber 32.

  Even when the pumping light input port for emergency pumping light is provided on the one end 32a side of the optical amplifying optical fiber 32 as in this modification, the replacement method described in the second embodiment is used. It can be performed suitably, and there can exist an effect similar to 2nd Embodiment.

(Sixth Modification)
FIG. 15 is a diagram illustrating a configuration of an optical amplification module 1H according to the sixth modification. As shown in FIG. 15, the optical amplification module 1H includes an optical unit 30C and a substrate 40C. The configuration of the optical unit 30C is the same as that of the optical unit 30A in the second embodiment except that the optical unit 30C does not have the excitation light input port 35a. The configuration of the substrate 40C is the same as the substrate 40A of the second embodiment except that the excitation light source 41 and the excitation light output port 45a are not provided.

  Even when the normal excitation light source is provided only on the other end 32b side of the optical amplification optical fiber 32 as in this modification, the replacement method described in the second embodiment can be suitably performed. The same effects as those of the second embodiment can be achieved.

(Seventh Modification)
FIG. 16 is a diagram illustrating a configuration of an optical amplification module 1J according to a seventh modification. As shown in FIG. 16, the optical amplification module 1J includes an optical unit 30D and a substrate 40D. The configuration of the optical unit 30D is the same as that of the optical unit 30B of the fifth modified example (see FIG. 14) except that it does not have the excitation light input port 35b. The configuration of the substrate 40D is the same as that of the substrate 40A of the second embodiment, except that the excitation light source 42 and the excitation light output port 45b are not provided.

  Even if the normal excitation light source is provided only on the one end 32a side of the optical fiber 32 for light amplification as in this modification, the replacement method described in the second embodiment can be suitably performed, The same effects as those of the second embodiment can be achieved.

(Eighth modification)
FIG. 17 is a diagram illustrating a configuration of an optical amplification module 1K according to an eighth modification. As shown in FIG. 17, the optical amplification module 1K includes an optical unit 30E and a substrate 40A. The optical unit 30E further includes a pumping light input port 35g and an optical coupler 36f in the fifth modified example (see FIG. 14) in addition to the configuration of the optical unit 30A of the second embodiment. That is, in the optical unit 30E, emergency pumping light can be input to both one end 32a and the other end 32b of the optical fiber 32 for optical amplification. The configuration of the substrate 40A is the same as that in the second embodiment.

  Even when the emergency pumping light can be input to both the one end 32a and the other end 32b of the optical amplification optical fiber 32 as in this modification, the replacement method described in the second embodiment is preferably performed. The same operational effects as those of the second embodiment can be obtained.

  DESCRIPTION OF SYMBOLS 1A-1K ... Optical amplification module, 10A-10E, 40A-40D ... Board | substrate, 10f ... Wiring board, 10g ... Connector, 11, 32 ... Optical fiber for optical amplification, 12, 13, 41, 42 ... Excitation light source, 14a- 14c, 27, 43a to 43c ... photodiode, 15, 16, 31 ... signal light input port, 17 ... signal light output port, 18, 44 ... control unit, 20A, 20B, 20E, 30A-30E ... light unit, 21 , 22 ... Signal light input port, 23, 33 ... Optical splitter, 24, 34 ... Signal light output port, 35a to 35c ... Excitation light input port.

Claims (5)

A first excitation light source that generates excitation light, and a substrate on which at least one of one end and the other end is mounted with an optical fiber for optical amplification that receives the excitation light and amplifies signal light input from the one end;
A first signal light input port that is optically coupled to the other end of the optical fiber for optical amplification and receives the amplified signal light, and optically connected to the first signal light input port via an optical coupler And a signal light output port for outputting the amplified signal light to the outside, and an optical unit detachably attached to the substrate,
The optical unit further includes a second signal light input port optically coupled to the signal light output port via the optical coupler ,
An optical amplification module, wherein an emergency signal light that substitutes for the amplified signal light is input to the second signal light input port from a signal source provided outside the substrate. A substrate on which a first excitation light source for generating excitation light is mounted;
At least one of the one end and the other end receives the pumping light and amplifies the signal light input from the one end, and at least one of the one end and the other end of the optical amplification optical fiber is optical the first excitation light input port for receiving said excitation light from said first pumping light source is coupled to, the signal light after amplification is optically coupled to the other end of the front Symbol light amplifying optical fiber A signal light output port that outputs to the outside , and a second signal light output port that is optically coupled to the other end of the optical fiber for optical amplification, and is detachably attached to the substrate With an optical unit,
The substrate includes a signal light input port coupled to the second signal light output port, light intensity detection means for detecting the intensity of the amplified signal light input from the signal light input port, and the light A controller that controls the intensity of the excitation light of the first excitation light source so that the intensity of the amplified signal light approaches a predetermined value based on the detection result of the intensity detection means;
The optical unit further includes a second excitation light input port optically coupled to at least one of one end and the other end of the optical amplification optical fiber,
An optical amplifying module, wherein emergency pumping light as an alternative to the pumping light is input to the second pumping light input port from a second pumping light source provided outside the substrate. Light intensity detecting means for detecting the intensity of the signal light after amplification;
And a controller that controls the intensity of the excitation light of the first excitation light source so that the intensity of the amplified signal light approaches a predetermined value based on the detection result of the light intensity detection means. The optical amplification module according to claim 1 , wherein: A first excitation light source that generates excitation light, and a substrate on which at least one of one end and the other end is mounted with an optical fiber for optical amplification that receives the excitation light and amplifies signal light input from the one end; A signal light input port for receiving the amplified signal light from the optical fiber for optical amplification, a signal light output port for outputting the amplified signal light to the outside, and a second optically coupled to the signal light output port And a method of replacing the substrate of an optical amplification module comprising an optical unit having a signal light input port and detachably attached to the substrate,
An emergency input step of inputting an emergency signal light as a substitute for the amplified signal light from a signal source provided outside the substrate to the second signal light input port;
The intensity of the emergency signal light is detected while detecting the intensity of the superimposed light of the signal light and the emergency signal light after amplification and controlling the intensity of the excitation light so that the intensity approaches a predetermined value. Gradually increasing the intensity to a first predetermined value and gradually increasing the intensity of the emergency signal light until the intensity of the excitation light falls below a second predetermined value;
Confirming that the intensity of the excitation light is below the second predetermined value;
An excitation light stopping step for stopping the output of the excitation light from the first excitation light source;
A detaching step for detaching the optical unit from the substrate;
A mounting step of attaching the optical unit to the substrate for replacement;
An excitation light output step for outputting the excitation light from the first excitation light source mounted on the replacement substrate;
Reducing the intensity of the emergency signal light from the signal source;
Checking the alarm state of the light amplification module and the state of the first excitation light source;
A step of removing the signal source from the second signal light input port; and a method of replacing the excitation light source of the optical amplification module. A substrate on which a first pumping light source that generates pumping light is mounted; an optical fiber for optical amplification that receives the pumping light at least one of one end and the other end and amplifies signal light input from the one end; the first excitation light input port for providing the first excitation light source excitation light receiving said excitation light to said optical amplifying optical fiber, the signal light output port for outputting said signal light after the amplification to the outside, before Symbol A second pumping light input port optically coupled to at least one of the one end and the other end of the optical amplification optical fiber, and a second signal optically coupled to the other end of the optical amplification optical fiber A method of replacing the substrate of an optical amplification module comprising an optical unit having an optical output port and detachably attached to the substrate,
The substrate includes a signal light input port coupled to the second signal light output port, light intensity detection means for detecting the intensity of the amplified signal light input from the signal light input port, and the light A controller that controls the intensity of the excitation light of the first excitation light source so that the intensity of the amplified signal light approaches a predetermined value based on the detection result of the intensity detection means;
An emergency input step of inputting emergency excitation light as an alternative to the excitation light from a second excitation light source provided outside the substrate to the second excitation light input port;
An excitation light stopping step for stopping the output of the excitation light from the first excitation light source;
A detaching step for detaching the optical unit from the substrate;
A mounting step of attaching the optical unit to the substrate for replacement;
An excitation light output step for outputting the excitation light from the first excitation light source mounted on the replacement substrate;
Removing the second pumping light source from the second pumping light input port. A method for replacing the pumping light source of the optical amplification module.

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