Laser module

Abstract

To provide a laser module that can adjust the output of multiple DC / DC converters.SOLUTION: A laser module includes: a first pump laser module; a first DC / DC converter including a first terminal connected to a first terminal of the first pump laser module and a second terminal connected to a second terminal of the first pump laser module; a second pump laser module including a first terminal connected to the second terminal of the first pump laser module; a second DC / DC converter including a first terminal connected to the first terminal of the second pump laser module and a second terminal connected to the second terminal of the second pump laser module; a control circuit connected to the first DC / DC converter and the second DC / DC converter; and a Zener diode connected to the first DC / DC converter and the second DC / DC converter.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a laser module. [Background technology]

[0002] Patent Document 1 discloses a laser module equipped with a DC / DC converter that inputs a predetermined voltage and outputs it to multiple loads to supply a predetermined current to each of the loads when a constant current is supplied to a single power line. The laser module includes a current control circuit having a voltage-dividing resistor that generates a reference voltage according to the voltage output from the DC / DC converter and a current-detection resistor that generates a current-detection voltage according to the current flowing through the load. The current control circuit also includes a feedback circuit that compares the reference voltage with the current-detection voltage and outputs a control signal representing the comparison result to the DC / DC converter. The laser module includes multiple circuit elements, each including one or more Zener diodes connected in parallel at a terminal that inputs a predetermined voltage to each DC / DC converter. The laser module includes multiple circuit elements connected in series with each other, and a system current is supplied to the multiple circuit elements connected in series with each other from an external power source. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2022 / 158311 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the laser module described in Patent Document 1, because Zener diodes were connected in parallel to each DC / DC converter, the output of each DC / DC converter could not be adjusted individually and only constant control at a predetermined voltage value was possible. Therefore, an object of the present disclosure is to provide a laser module that can adjust the output of multiple DC / DC converters individually. [Means for solving the problem]

[0005] The laser module according to the first aspect of the present disclosure includes: a first pump laser module having a first terminal and a second terminal; a first DC / DC converter having a first terminal connected to the first terminal of the first pump laser module and a second terminal connected to the second terminal of the first pump laser module; a second pump laser module having a first terminal connected to the second terminal of the first pump laser module and a second terminal; a second DC / DC converter having a first terminal connected to the first terminal of the second pump laser module and a second terminal connected to the second terminal of the second pump laser module; a control circuit connected to the first DC / DC converter and the second DC / DC converter; a Zener diode connected to the first DC / DC converter and the second DC / DC converter;

[0006] A laser module according to a second aspect of the present disclosure includes: n (n is a natural number of 2 or more) sets of pump laser modules and DC / DC converters; a control circuit connected to the n DC / DC converters; Zener diodes connected to the n DC / DC converters, A laser module in which n pairs of pump laser modules and DC / DC converters are arranged so that a first terminal of the kth (k is a natural number from 1 to n) pump laser module is connected to a first terminal of the kth DC / DC converter, and a second terminal of the kth pump laser module is connected to a second terminal of the kth DC / DC converter. [Effects of the Invention]

[0007] The present disclosure provides a laser module capable of adjusting the outputs of multiple DC / DC converters individually. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a circuit diagram of a laser module according to the present disclosure. [Figure 2] FIG. 1 is a circuit diagram of a related laser module. DETAILED DESCRIPTION OF THE INVENTION

[0009] Embodiment The laser module according to the embodiment is a pump laser module that supplies pump light to an erbium-doped fiber that amplifies light in a submarine optical repeater applied to a large-capacity submarine communication system. The laser module is provided with a DC / DC converter in each pump laser module, thereby supplying a current to the optical amplifier pair that is greater than or equal to the current supplied from the land station, thereby increasing the output power of the pump light and realizing a high-output or multi-core submarine repeater.

[0010] The related laser module is explained using Figure 2. DWDM (Dense Wavelength Division Multiplexing) systems are widely used in undersea communication networks. The undersea optical repeaters used in communication networks use optical amplifiers with erbium-doped fibers to amplify attenuated optical signals to an appropriate level.

[0011] 2, the associated laser module 200 adjusts the current of pump laser modules 203 and 206 using current control circuits 202 and 205 and Zener diodes 204 and 207, and supplies the pump light to erbium-doped fibers (EDFs) 209 installed in the UP and DOWN directions of the fiber pair via an optical coupler 208. The signal is amplified by the EDFs 209 and enters a gain flattening module (GFF) 210, where it is emitted as optical signal light.

[0012] Currently, in order to expand transmission capacity in submarine communication networks, it is necessary to increase the output power of submarine optical repeaters and the number of fiber pairs, which requires higher output power from pump laser modules.

[0013] However, the configuration shown in Fig. 2 has a problem in that the current that can be passed through the pump laser module 201 cannot exceed the current (To Cable Conductor) supplied from the power source (PFE (Power Feeding Equipment)) of the land terminal station. To solve this problem, methods have been taken to increase the power supply current of the power source set up on land, or to increase the number of pump laser modules shown in Fig. 2 from two to four, etc.

[0014] In the first solution, the upper limit current of the PFE currently in common use is 1.3A, which is insufficient for the current (~1.8A) allowed for high-power pump laser modules.

[0015] Furthermore, if the second solution is to increase the number of pump laser modules, the method for controlling the pump laser modules within the optical amplifier pair becomes complicated. The number of couplers that combine the pump light increases, and the method for distributing that pump light to the erbium-doped fiber becomes complicated, resulting in an increase in the size of the equipment. Furthermore, it becomes difficult to select pump laser modules that have the same current-light characteristics, which poses the problem of making it difficult to manufacture submarine optical repeaters.

[0016] An example of the configuration of the laser module 100 will be described below with reference to Fig. 1. As shown in Fig. 1, the laser module 100 includes a first pump laser module 101, a first DC / DC converter 102, a second pump laser module 103, a second DC / DC converter 104, a control circuit 105, and a Zener diode 106.

[0017] The first pump laser module 101 uses a semiconductor laser that emits near-infrared light with a wavelength of, for example, 1.48 μm or 0.98 μm. That is, the first pump laser module is represented as a diode on the circuit and is expressed as a load. The first pump laser module 101 has a negative first terminal and a positive second terminal.

[0018] The first DC / DC converter 102 is provided to pass a current equal to or greater than the current from the power supply to the first pump laser module 101. To this end, the first DC / DC converter 102 has a negative first terminal connected to the first terminal of the first pump laser module, and a positive second terminal connected to the second terminal of the first pump laser module.

[0019] The second excitation laser module 103 can use the same semiconductor laser as the first excitation laser module 101. The second excitation laser module 103 has a negative first terminal connected to the second terminal of the first excitation laser module 101, and a positive second terminal.

[0020] The second DC / DC converter 104 is provided to pass a current equal to or greater than the current from the power supply to the second pump laser module 103. Therefore, the second DC / DC converter 104 has a negative first terminal connected to the first terminal of the second pump laser module 103 and a positive second terminal connected to the second terminal of the second pump laser module 103.

[0021] The control circuit 105 independently controls the first DC / DC converter 102 and the second DC / DC converter 104. Therefore, the control circuit 105 is connected to each of the first DC / DC converter 102 and the second DC / DC converter 104.

[0022] The Zener diode 106 is connected in series with the first DC / DC converter 102 and the second DC / DC converter 104. The Zener diode 106 keeps constant the voltage applied to the first DC / DC converter 102 and the second DC / DC converter 104 connected in series. Therefore, the first DC / DC converter 102 and the second DC / DC converter 104 are controlled independently, and the first pump laser module 101 and the second pump laser module 103 output independently.

[0023] In the case of two pump laser modules, the fourth terminal of the first DC / DC converter 102 is connected to the third terminal of the second DC / DC converter 104, and the fourth terminal of the second DC / DC converter 104 is connected to the first terminal of the Zener diode 106. In addition, the second terminal of the Zener diode 106 is connected to the third terminal of the first DC / DC converter 102.

[0024] Furthermore, when there are two pump laser modules, the fourth terminal of the second DC / DC converter 104 and the first terminal of the Zener diode 106 are connected to the power supply voltage, and the third terminal of the first DC / DC converter 102 and the second terminal of the Zener diode 106 are connected to the ground voltage.

[0025] If there are n pump laser modules (n is a natural number of 2 or greater) and they are paired with n DC / DC converters, the control circuit is connected to each of the n DC / DC converters. Also, the Zener diodes are connected in series with the n DC / DC converters.

[0026] Furthermore, the first negative terminal of the k-th (k is a natural number from 1 to n) pump laser module is connected to the first negative terminal of the k-th DC / DC converter, and the second positive terminal of the k-th pump laser module is connected to the second positive terminal of the k-th DC / DC converter, In this manner, n pairs of pump laser modules and DC / DC converters are arranged.

[0027] In this case, the fourth terminal of the l-th DC / DC converter (l is a natural number from 1 to n-1) is connected to the third terminal of the l+1-th DC / DC converter. The fourth terminal of the n-th DC / DC converter is connected to the first terminal of the Zener diode. In addition, the second terminal of the Zener diode is connected to the third terminal of the first DC / DC converter.

[0028] In this case, the fourth terminal of the nth DC / DC converter and the first terminal of the Zener diode are connected to the power supply voltage, and the third terminal of the first DC / DC converter and the second terminal of the Zener diode are connected to the ground voltage.

[0029] In this way, two or more pump laser modules can be arranged in series to obtain amplified laser light.

[0030] The current supplied from the land station is increased by a DC / DC converter that is paired one-to-one with the pump laser module inside the optical amplifier pair. The output of the pump laser modules that make up the optical amplifier pair is increased to the required level. At this time, the current of each pump laser module can be adjusted by a control circuit.

[0031] The upper limit of the current to the pump laser module of the related laser module was the current of the cable conductor supplied from the power supply of the land station.The laser module of the present disclosure is able to pass a current greater than the current from the cable conductor by attaching a DC / DC converter to each pump laser module of the optical amplifier pair, and can supply a current that can increase the output of the pump laser module.

[0032] Furthermore, for optical amplifier pairs, only a DC / DC converter needs to be added, and there is no need to increase the number of pump laser modules. Therefore, the number of pump laser modules can remain at two. Because the control circuit adjusts the optical output of each pump laser module, there is no need to select pump laser modules to match the optical output for the same current. Furthermore, there is no need to change the distribution of pump light to the erbium-doped fiber by adding an optical coupler, which would be necessary if the number of pump laser modules were increased.

[0033] This makes it possible to increase the output of the undersea optical repeater and the optical amplifier pair.

[0034] Although the present disclosure has been described above with reference to the embodiments, the present disclosure is not limited to the above-described embodiments. Various modifications that can be understood by those skilled in the art can be made to the configuration and details of the present disclosure within the scope of the present disclosure. Furthermore, each embodiment can be combined with other embodiments as appropriate.

[0035] Each drawing is merely an example for describing one or more embodiments. Each drawing may relate not only to one particular embodiment, but also to one or more other embodiments. As will be understood by those skilled in the art, various features or steps described with reference to any one drawing can be combined with features or steps shown in one or more other drawings to create, for example, an embodiment not explicitly shown or described. Not all features or steps shown in any one drawing are necessary to describe an exemplary embodiment, and some features or steps may be omitted. The order of steps described in any drawing may be changed as appropriate.

[0036] A part or all of the above-described embodiments can be described as, but not limited to, the following supplementary notes. (Appendix 1) a first pump laser module having a first terminal and a second terminal; a first DC / DC converter having a first terminal connected to the first terminal of the first pump laser module and a second terminal connected to the second terminal of the first pump laser module; a second pump laser module having a first terminal connected to the second terminal of the first pump laser module and a second terminal; a second DC / DC converter having a first terminal connected to the first terminal of the second pump laser module and a second terminal connected to the second terminal of the second pump laser module; a control circuit connected to the first DC / DC converter and the second DC / DC converter; a Zener diode connected to the first DC / DC converter and the second DC / DC converter. (Appendix 2) a fourth terminal of the first DC / DC converter is connected to a third terminal of the second DC / DC converter; a fourth terminal of the second DC / DC converter is connected to a first terminal of the Zener diode; 2. The laser module of claim 1, wherein a second terminal of the Zener diode is connected to a third terminal of the first DC / DC converter. (Appendix 3) a fourth terminal of the second DC / DC converter and a first terminal of the Zener diode are connected to a power supply voltage; 2. The laser module of claim 1, wherein a third terminal of the first DC / DC converter and a second terminal of the Zener diode are connected to a ground voltage. (Appendix 4) n (n is a natural number of 2 or more) sets of pump laser modules and DC / DC converters; a control circuit connected to the n DC / DC converters; Zener diodes connected to the n DC / DC converters, A laser module in which n pairs of pump laser modules and DC / DC converters are arranged so that a first terminal of the kth (k is a natural number from 1 to n) pump laser module is connected to a first terminal of the kth DC / DC converter, and a second terminal of the kth pump laser module is connected to a second terminal of the kth DC / DC converter. (Appendix 5) the fourth terminal of the l-th DC / DC converter (l is a natural number from 1 to n-1) is connected to the third terminal of the l+1-th DC / DC converter, a fourth terminal of the n-th DC / DC converter is connected to a first terminal of a Zener diode; 5. The laser module according to claim 4, wherein a second terminal of the Zener diode is connected to a third terminal of a first DC / DC converter. (Appendix 6) a fourth terminal of the n-th DC / DC converter and a first terminal of the Zener diode are connected to a power supply voltage; 5. The laser module according to claim 4, wherein a third terminal of a first DC / DC converter and a second terminal of the Zener diode are connected to a ground voltage. [Explanation of symbols]

[0037] 100 laser module, 101 first pump laser module, 102 first DC / DC converter, 103 second pump laser module, 104 second DC / DC converter, 105 control circuit, 106 Zener diode, 200 related laser module, 201 pump laser module, 202 current control circuit, 203 pump laser module, 204 Zener diode, 205 current control circuit, 206 pump laser module, 207 Zener diode, 208 optical coupler, 209 erbium-doped fiber, 210 gain flattening module

Claims

1. a first pump laser module having a first terminal and a second terminal; a first DC / DC converter including a first terminal connected to the first terminal of the first pump laser module and a second terminal connected to the second terminal of the first pump laser module; a second pump laser module including a first terminal connected to the second terminal of the first pump laser module, and a second terminal; a second DC / DC converter including a first terminal connected to the first terminal of the second pump laser module and a second terminal connected to the second terminal of the second pump laser module; a control circuit connected to the first DC / DC converter and the second DC / DC converter; a Zener diode connected to the first DC / DC converter and the second DC / DC converter.

2. a fourth terminal of the first DC / DC converter is connected to a third terminal of the second DC / DC converter; a fourth terminal of the second DC / DC converter is connected to a first terminal of the Zener diode; 2. The laser module according to claim 1, wherein a second terminal of the Zener diode is connected to a third terminal of the first DC / DC converter.

3. a fourth terminal of the second DC / DC converter and a first terminal of the Zener diode are connected to a power supply voltage; 2. The laser module according to claim 1, wherein a third terminal of the first DC / DC converter and a second terminal of the Zener diode are connected to a ground voltage.

4. n (n is a natural number of 2 or more) sets of pump laser modules and DC / DC converters; a control circuit connected to the n DC / DC converters; Zener diodes connected to the n DC / DC converters, A laser module in which n sets of pump laser modules and DC / DC converters are arranged so that a first terminal of the kth (k is a natural number from 1 to n) pump laser module is connected to a first terminal of the kth DC / DC converter, and a second terminal of the kth pump laser module is connected to a second terminal of the kth DC / DC converter.

5. the fourth terminal of the l-th DC / DC converter (l is a natural number from 1 to n-1) is connected to the third terminal of the l+1-th DC / DC converter, a fourth terminal of the n-th DC / DC converter is connected to a first terminal of a Zener diode; 5. The laser module according to claim 4, wherein a second terminal of the Zener diode is connected to a third terminal of a first DC / DC converter.

6. a fourth terminal of the n-th DC / DC converter and a first terminal of the Zener diode are connected to a power supply voltage; 5. The laser module according to claim 4, wherein a third terminal of the first DC / DC converter and a second terminal of the Zener diode are connected to a ground voltage.

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