Laser generating circuit and erbium-doped fiber amplifier

Abstract

The present application provides a laser generation circuit and an erbium-doped fiber amplifier, relating to the field of optical communication technologies. The jitter signal generation circuit includes: a jitter signal module, an analog signal module, and a clock signal module; the first input end of the jitter signal module is connected to the output end of the analog signal module, the control end of the jitter signal module is connected to the output end of the clock signal module, and the output end of the jitter signal module is used to output a jitter signal. By connecting the jitter signal module to the analog signal module and the clock signal module respectively, the present application can adjust the amplitude of the analog signal output by the analog signal module to achieve the adjustment of the amplitude of the jitter signal, and can adjust the frequency of the clock signal output by the clock signal module to complete the adjustment of the frequency of the jitter signal, so as to be compatible with lasers provided by multiple manufacturers, without adding optical attenuation devices at the output end of the laser, and effectively reducing the cost of preparing the EDFA.

Description

Technical Field

[0001] This application relates to the field of optical communication technologies, and in particular, to a laser generation circuit and an erbium-doped fiber amplifier. Background Art

[0002] With the continuous development of optical communication technologies, EDFA has also developed accordingly as a core device for optical communication, having a relatively high impact on the performance of optical communication.

[0003] The laser is a core device in the EDFA. The EDFA usually includes lasers from multiple manufacturers. However, the current thresholds required by different lasers are different. Moreover, when the current received by the laser is near the current threshold, the laser may experience stimulated emission, resulting in problems such as non-linearity and instability. Therefore, an optical attenuation device can be added at the output end of the laser to improve the reliability of the laser.

[0004] However, adding an optical attenuation device at the output end of the laser requires increasing the power of the laser to meet the corresponding requirements, resulting in the problem of increased cost. Summary of the Invention

[0005] This application provides a laser generation circuit and an erbium-doped fiber amplifier, which solve the problem in the prior art that adding an optical attenuation device at the output end of the laser will increase the cost.

[0006] To achieve the above object, in a first aspect, an embodiment of this application provides a jitter signal generation circuit. The jitter signal generation circuit includes: a jitter signal module, an analog signal module, and a clock signal module;

[0007] The first input end of the jitter signal module is connected to the output end of the analog signal module, the control end of the jitter signal module is connected to the output end of the clock signal module, and the output end of the jitter signal module is used to output a jitter signal;

[0008] The analog signal module is used to input an analog signal to the jitter signal module. The clock signal module is used to control the jitter signal module to output the jitter signal according to the clock signal. The jitter signal is generated according to the analog signal and the clock signal.

[0009] Optionally, the jitter signal module includes a switching device;

[0010] The control end of the switching device is connected to the output end of the clock signal module, the input end of the switching device is connected to the output end of the analog signal module, and the output end of the switching device is the output end of the jitter signal module.

[0011] Optionally, the second input terminal of the jitter signal module is connected to the ground potential;

[0012] When the signal output by the clock signal module is at a low level, the jitter signal module outputs a low-level signal through the ground potential connected to the second input terminal;

[0013] When the signal output by the clock signal module is at a high level, the jitter signal module outputs the analog signal through the analog signal module connected to the first input terminal.

[0014] Optionally, the analog signal module is a digital-to-analog converter.

[0015] Optionally, the jitter signal module is a single-pole double-throw analog switch.

[0016] In a second aspect, an embodiment of the present application provides a laser output circuit, which includes: a control module, a driving circuit, a laser, and a jitter signal generation circuit as described in any one of the first aspects;

[0017] The control module is connected to the input terminal of the driving circuit, the jitter signal generation circuit is connected to the input terminal of the driving circuit through a coupling capacitor, and the output terminal of the driving circuit is connected to the laser;

[0018] The driving circuit outputs a driving signal according to the control signal output by the control module. The driving signal is used to drive the laser to emit light. The driving signal includes a jitter signal, and the jitter signal is added to the driving signal by the jitter signal generation circuit through the coupling capacitor.

[0019] Optionally, a protection resistor is connected in series between the control module and the driving circuit.

[0020] Optionally, the laser is a pump laser.

[0021] In a third aspect, an embodiment of the present application provides an erbium-doped fiber amplifier, which includes: a laser output circuit as described in any one of the second aspects.

[0022] A jitter signal generation circuit provided by an embodiment of the present application can adjust the amplitude of the analog signal output by the analog signal module by connecting the jitter signal module to the analog signal module and the clock signal module respectively, so as to adjust the amplitude of the jitter signal, and can adjust the frequency of the clock signal output by the clock signal module to complete the adjustment of the frequency of the jitter signal. Therefore, it can be matched with lasers provided by multiple manufacturers, and there is no need to add an optical attenuation device at the output end of the laser, which can effectively reduce the cost of preparing an EDFA. Description of the Drawings

[0023] Figure 1 Schematic diagram of a jitter signal generation circuit provided by an embodiment of the present application;

[0024] Figure 2 Schematic diagram of a laser output circuit provided by an embodiment of the present application;

[0025] Figure 3 Waveform diagram of a drive signal provided by an embodiment of the present application;

[0026] Figure 4 Waveform diagram of another drive signal provided by an embodiment of the present application. Detailed implementation manners

[0027] In the following description, specific details such as specific system structures and technologies are presented for the purpose of illustration rather than limitation, so as to thoroughly understand the embodiments of the present application. However, those skilled in the art should clearly understand that the present application can also be implemented in other embodiments without these specific details.

[0028] The terms used in the following embodiments are only for the purpose of describing specific embodiments and are not intended to limit the present application. As used in the specification and appended claims of the present application, the singular forms "a", "the", "above-mentioned", and "this" are also intended to include the expression forms such as "one or more", unless there is a clear opposite indication in the context.

[0029] Refer to Figure 1 , Figure 1 Schematic diagram of a jitter signal generation circuit provided by an embodiment of the present application. As Figure 1 shown, the jitter signal generation circuit may include: an analog signal module 010, a clock signal module 020, and a jitter signal module 030.

[0030] Among them, the first input end (IN1) of the jitter signal module is connected to the output end of the analog signal module, the control end (CTL) of the jitter signal module is connected to the output end of the clock signal module, and the output end (OUT) of the jitter signal module is used to output a jitter signal.

[0031] Correspondingly, the analog signal module can input an analog signal to the jitter signal module, and the clock signal module can control the jitter signal module to output a jitter signal according to the clock signal. Among them, the analog signal can be a high-level signal continuously output by the analog signal module, the clock signal can be a square wave output by the clock signal module, and the jitter signal can be a Dither signal. The present application does not limit the analog signal, clock signal, and jitter signal.

[0032] Moreover, the amplitude of the dither signal is consistent with the amplitude of the analog signal, and the frequency of the dither signal is consistent with the frequency of the clock signal.

[0033] It should be noted that in practical applications, the analog signal module can be a digital-to-analog converter, and the analog signal module can be a single-pole double-throw analog switch or a semiconductor device (such as a triode or an MOS transistor). The embodiments of the present application do not limit the analog signal module.

[0034] For example, the dither signal module may include a switching device. The control end of the switching device is connected to the output end of the clock signal module, the input end of the switching device is connected to the output end of the analog signal module, and the output end of the switching device is the output end of the dither signal module.

[0035] If the switching device is an MOS transistor, the control end of the switching device can be the gate of the MOS transistor, the input end of the switching device can be the source or drain of the MOS transistor, and the output end of the switching device can be the drain or source of the MOS transistor.

[0036] In addition, referring to Figure 1 , the dither signal module may further include a second input terminal (IN2), and the second input terminal is connected to the ground potential.

[0037] During the operation of the dither signal generation circuit, the analog signal module can continuously input an analog signal to the dither signal module, and the clock signal module can also continuously input a clock signal to the dither signal module. When the clock signal is at a low level, the dither signal module can output a low-level signal as the dither signal through the ground potential connected to the second input terminal; when the clock signal is at a high level, the dither signal module can output an analog signal as the dither signal according to the analog signal input by the analog signal module.

[0038] In summary, a dither signal generation circuit provided by an embodiment of the present application can adjust the amplitude of the analog signal output by the analog signal module by connecting the dither signal module to the analog signal module and the clock signal module respectively, so as to adjust the amplitude of the dither signal, and can adjust the frequency of the clock signal output by the clock signal module to complete the adjustment of the frequency of the dither signal, so that it can be matched with lasers provided by multiple manufacturers, and there is no need to add an optical attenuation device at the output end of the laser, which can effectively reduce the cost of preparing the EDFA.

[0039] Referring to Figure 2 , Figure 2 is a schematic structural diagram of a laser output circuit provided by an embodiment of the present application. As Figure 2 shown, the laser output circuit may include: a corresponding dither signal generation circuit 040, a control module 050, a drive circuit 060, and a laser 070 as Figure 1 corresponding.

[0040] Among them, the control module can be connected to the input end of the driving circuit. The jitter signal generation circuit can be connected to the input end of the driving circuit through a coupling capacitor (C1). The output end of the driving circuit is connected to the laser. Moreover, a protection resistor (R1) can be connected in series between the control module and the driving circuit.

[0041] In addition, the above-mentioned driving circuit can be a constant current driving circuit, and the laser can be a pump laser or other types of lasers. The embodiments of the present application do not limit the driving circuit and the laser.

[0042] Correspondingly, the driving circuit can receive the control signal output by the control module and the jitter signal output by the jitter signal generation circuit, and output a driving signal according to the control signal, so as to drive the laser to emit light through the driving signal.

[0043] Among them, the control signal is used to control the optical power of the laser, and the control signal can be a voltage signal. The driving signal can be a current signal and is obtained by converting the control signal.

[0044] Moreover, the driving signal can include a jitter signal, and the jitter signal is added to the driving signal by the jitter signal generation circuit through a coupling capacitor. In addition, the coupling capacitor can be selected according to the frequency of the jitter signal. For example, the coupling capacitor can be calculated according to the formula F = 1 / (2*π*R1*C1), where F is the frequency of the jitter signal, R1 is the resistance value corresponding to the protection resistor, C1 is the capacitance value corresponding to the coupling capacitor, and π is the pi.

[0045] Specifically, the jitter signal can be AC-coupled to the control signal through C1, so that the jitter signal can be added to the driving signal. When the control signal is zero, the peak value of the jitter signal in the driving signal can be adjusted to be consistent with the threshold current of the laser. When the driving signal is a current less than the threshold current of the laser, the wave peak of the driving signal will exceed the threshold current of the laser, prompting the laser to emit light. Due to the characteristics of the erbium-doped fiber, the output optical power can be directly equivalent to the effective value, so that it is difficult to stably control the optical power caused by a current value near the threshold current, which becomes the effective value of multiple pulses, and the current will not stay in the unstable region, thus increasing the stability of the optical power control.

[0046] See Figure 3 , Figure 3 which is a waveform schematic diagram of a driving signal provided by an embodiment of the present application. As Figure 3 shown, the horizontal axis T represents time, and the vertical axis ILD represents the amplitude of the driving signal, that is, the magnitude of the driving current; ITH is the threshold current of the laser, T1 is the period of the jitter signal, F = 1 / T1, F is the frequency of the jitter signal, and the frequency of the jitter signal is greater than the response frequency of the erbium-doped fiber.

[0047] At this time, the voltage of the control signal output by the control module is 0. By adjusting the analog signal module, the amplitude of the jitter signal can be controlled so that the peak of the jitter signal can just reach the threshold current of the laser.

[0048] See Figure 4 , Figure 4 which is a waveform diagram of another driving signal provided by an embodiment of the present application. As Figure 4 shown, the horizontal axis T represents time; the vertical axis ILD represents the amplitude of the driving signal, that is, the magnitude of the driving current; ITH is the threshold current of the laser, ISET is the driving current signal converted from the laser control signal, ISET is a current less than ITH, and T1 is the period of the jitter signal.

[0049] As Figure 4 shown, the driving signal is coupled with the jitter signal. The upper part of the jitter signal has exceeded the non-linear region near ITH, and the part exceeding ITH will drive the laser to output optical power. If the effective value of this part is taken, a very small optical power can be output without outputting the same small optical power signal in the non-linear region.

[0050] In summary, after adding the jitter signal to the driving signal, when a small optical power signal needs to be generated, the unstable control region can be avoided by the method of intermittent light emission and taking the effective value, thereby increasing the stability of optical power control.

[0051] The embodiment of the present application also provides an erbium-doped fiber amplifier, including: as Figure 2 the corresponding laser output circuit. Other components included in the erbium-doped fiber amplifier will not be described in detail here. The description of the laser output circuit can be referred to the foregoing and will not be described in detail here either.

[0052] In the above embodiments, the descriptions of the respective embodiments have their own emphases. For parts not detailed or recorded in a certain embodiment, the relevant descriptions of other embodiments can be referred to.

[0053] Those of ordinary skill in the art can realize that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods for each specific application to implement the described functions, but such implementation should not be considered to exceed the scope of the present application.

[0054] In the embodiments provided in the present application, it should be understood that the disclosed apparatus / devices and methods can be implemented in other ways. For example, the apparatus / device embodiments described above are merely illustrative. For example, the division of the modules or units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed coupling or direct coupling or communication connection to each other can be through some interfaces. The indirect coupling or communication connection of the devices or units can be in electrical, mechanical or other forms.

[0055] It should be understood that when used in the specification and appended claims of the present application, the term "comprising" indicates the presence of the described features, wholes, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or their combinations.

[0056] It should also be understood that the term "and / or" used in the specification and appended claims of the present application refers to any combination and all possible combinations of one or more of the related listed items, and includes these combinations.

[0057] As used in the specification and appended claims of the present application, the term "if" can be interpreted as "when", "once", "in response to determining", or "in response to detecting" depending on the context. Similarly, the phrase "if determined" or "if [the described condition or event] is detected" can be interpreted as meaning "once determined", "in response to determining", "once [the described condition or event] is detected", or "in response to detecting [the described condition or event]" depending on the context.

[0058] In addition, in the description of the specification and appended claims of the present application, the terms "first", "second", "third", etc. are only used for distinguishing descriptions and cannot be understood as indicating or implying relative importance.

[0059] The reference to "one embodiment" or "some embodiments" or the like described in the specification of the present application means that a specific feature, structure, or characteristic described in connection with the embodiment is included in one or more embodiments of the present application. Thus, the statements "in one embodiment", "in some embodiments", "in other some embodiments", "in still other embodiments", etc. that appear in different places in this specification do not necessarily all refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "comprising", "including", "having" and their variants all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0060] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than limiting them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A laser output circuit, characterized in that, The laser output circuit includes: a control module, a drive circuit, a laser, and a jitter signal generation circuit; The jitter signal generation circuit includes: a jitter signal module, an analog signal module, and a clock signal module; A first input end of the jitter signal module is connected to an output end of the analog signal module, a control end of the jitter signal module is connected to an output end of the clock signal module, and an output end of the jitter signal module is used for outputting a jitter signal; The analog signal module is used for inputting an analog signal to the jitter signal module, the clock signal module is used for controlling the jitter signal module, controlling the jitter signal module to output the jitter signal according to a clock signal, and the jitter signal is generated according to the analog signal and the clock signal; The control module is connected to an input end of the drive circuit, the jitter signal generation circuit is connected to the input end of the drive circuit through a coupling capacitor, and an output end of the drive circuit is connected to the laser; The drive circuit outputs a drive signal according to a control signal output by the control module, the drive signal is used for driving the laser to emit light, the drive signal includes a jitter signal, and the jitter signal is added to the drive signal by the jitter signal generation circuit through the coupling capacitor; The jitter signal module includes a switching device; A control end of the switching device is connected to an output end of the clock signal module, an input end of the switching device is connected to an output end of the analog signal module, and an output end of the switching device is an output end of the jitter signal module; A second input end of the jitter signal module is connected to a ground potential; When a signal output by the clock signal module is at a low level, the jitter signal module outputs a low-level signal through the ground potential connected to the second input end; When a signal output by the clock signal module is at a high level, the jitter signal module outputs the analog signal through the analog signal module connected to the first input end.

2. The laser output circuit according to claim 1, wherein The analog signal module is a digital-to-analog converter.

3. The laser output circuit according to claim 1, wherein The jitter signal module is a single-pole double-throw analog switch.

4. The laser output circuit according to claim 1, wherein, A protection resistor is connected in series between the control module and the drive circuit.

5. The laser output circuit according to claim 1 or 4, characterized in that, The laser is a pump laser.

6. An erbium-doped fiber amplifier, characterized in that, Including: The laser output circuit according to any one of claims 1 to 5.

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