CN111384662A - Directly-modulated laser drive circuit and directly-modulated laser system - Google Patents

Abstract

A direct-adjustment laser drive circuit is externally connected to a first input signal and a second input signal, and is connected to a power supply and a laser diode, the direct-adjustment laser drive circuit includes a current modulation module, and a neutralizer with a neutralization capacitor whose parameters can be independently set. and module, DC bias module, first anti-jamming module and second anti-jamming module, the direct modulation laser drive circuit adopts separate optimization methods to adjust different parameters of the capacitors in the neutralization module to eliminate The asymmetric bias caused by the laser diode load and drive circuit increases the bandwidth of the system, thereby improving the quality of the eye diagram obtained by the system test and suppressing the jitter of the system, solving the existing bandwidth in the traditional technical solution. Insufficient, poor eye diagram quality, and low jitter performance.

Description

Directly modulated laser drive circuit and direct modulated laser system

technical field

The present application belongs to the technical field of optical communication, and in particular, relates to a direct modulation laser drive circuit and a direct modulation laser system.

Background technique

At present, the traditional DC-coupled DML (Directly Modulated Laser, Directly Modulated Laser) system needs to provide a DC bias current to the laser, and the asymmetry of the anode and cathode drive circuits of the laser diode will lead to asymmetric bias. Since the impedance of the laser diode is relatively low, when the current changes rapidly, the parasitic inductance caused by the bonding line will cause a higher impedance than the impedance of the laser diode itself, which will cause serious transient spike waveforms in the time domain, which will seriously affect the system. bandwidth, eye diagram and jitter performance from system testing.

Therefore, the traditional technical solutions have the problems of insufficient bandwidth, poor eye diagram quality and low jitter performance.

SUMMARY OF THE INVENTION

In view of this, embodiments of the present application provide a direct modulation laser driving circuit and a direct modulation laser system, aiming at solving the problems of insufficient bandwidth, poor eye diagram quality and low jitter performance in the traditional technical solutions.

A first aspect of the embodiments of the present application provides a direct modulation laser drive circuit, which is externally connected to a first input signal and a second input signal, the direct modulation laser drive circuit is connected to a power supply through a first anti-interference module, and the direct modulation laser drive circuit is connected to a power supply through a first anti-interference module. The laser drive circuit is connected to the laser diode, and the anode of the laser diode is connected to the power supply through the first anti-interference module, and the direct modulation laser drive circuit includes:

A current modulation module, the current modulation module includes a first transistor, a second transistor, a first resistor, a first current sink and a second current sink, the base of the first transistor is connected to the first input signal, so The collector of the first transistor is connected to the laser diode, the collector of the first transistor is the first output end of the current modulation module, and the base of the second transistor is connected to the second control signal , the collector of the second transistor is connected to the cathode of the laser diode, the collector of the second transistor is the second output end of the current modulation module, and the first end of the first resistor is connected to the the emitter of the first transistor is connected to the first end of the first current sink, the second end of the first resistor is connected to the emitter of the second transistor and the first end of the second current sink, the second end of the first current sink and the second end of the second current sink are grounded in common;

A neutralization module, the neutralization module includes a first capacitor and a second capacitor, the first end of the first capacitor is connected to the collector of the first transistor, and the second end of the first capacitor is connected to the The base of the second transistor is connected, the first end of the second capacitor is connected to the base of the first transistor, and the second end of the second capacitor is connected to the collector of the second transistor. In the technology, the first capacitor and the second capacitor are differential coupling capacitors. In the present invention, different parameters are set and adjusted in a separate optimization manner to eliminate asymmetric bias; and

A DC bias module, the DC bias module includes a third current sink, the first end of the third current sink is the first end of the DC bias module, and the first end of the DC bias module passes through The second anti-interference module is connected to the cathode of the laser diode, the second end of the third current sink is the second end of the DC bias module, the second end of the DC bias module is grounded, the The DC bias module is used for providing a DC bias current to the laser diode.

In one embodiment, the neutralization module includes a first adjustment unit and a second adjustment unit for adjusting and neutralizing peak behavior, the first adjustment unit is connected in series with the first capacitor, and the first adjustment unit is connected in series with the first capacitor. Two adjustment units are connected in series with the second capacitor.

In one embodiment, the first adjustment unit includes a second resistor, the second adjustment unit includes a third resistor, the second resistor is connected in series with the first capacitor, and the third resistor is connected to the The second capacitor is connected in series.

In one embodiment, the current modulation module further includes a first mitigation unit and a second mitigation unit for mitigating transient spikes caused by parasitic inductance, and a first termination of the first mitigation unit is connected to the The first input signal, the second terminal of the first slowing unit is connected to the base of the first transistor, the first terminal of the second slowing unit is connected to the second input signal, the second slowing The second terminal of the cell is connected to the base of the second transistor.

In one embodiment, the current modulation module further includes a third mitigation unit for mitigating transient spikes caused by parasitic inductance, the third mitigating unit is connected in series with the first resistor.

In one of the embodiments, the direct modulation laser driving circuit further includes a servo loop module for improving and fixing the voltage margin of the transistor, the first input terminal of the servo loop module is connected with a preset voltage value, so The second input terminal of the servo loop module is connected to the center point of the first resistor, the third input terminal of the servo loop module is connected to the first input signal, and the fourth input terminal of the servo loop module is connected to the first input signal. The input terminal is connected to the second input signal, the first output terminal of the servo loop module is connected to the base of the first transistor, and the second output terminal of the servo loop module is connected to the second transistor base connection.

In one embodiment, the servo loop module includes a first comparator and a first operational amplifier, the non-inverting input terminal of the first comparator is the first input terminal of the servo loop module, the The negative input terminal of the first comparator is the second input terminal of the servo loop module, the output terminal of the first comparator is connected to the control terminal of the first operational amplifier, and the first operational amplifier is connected to the control terminal of the first operational amplifier. An input terminal is the third input terminal of the servo loop module, the second input terminal of the first operational amplifier is the fourth input terminal of the servo loop module, and the first output terminal of the first operational amplifier The terminal is the first output terminal of the servo loop module, and the second output terminal of the first operational amplifier is the second output terminal of the servo loop module.

In one of the embodiments, the current modulation module further includes a first compensation unit for compensating for bandwidth variation, the first compensation unit is connected in series to the bias input terminals of the first current sink and the second current sink.

In one of the embodiments, the direct modulation laser driving circuit further includes a second compensation unit for compensating for bandwidth variation, a first end of the second compensation unit is connected to the first output end of the current modulation module, The second end of the second compensation unit is connected to the second output end of the current modulation module.

A second aspect of the embodiments of the present application provides a direct modulation laser system, including the above-mentioned direct modulation laser drive circuit, a power supply, a first anti-jamming module, a second anti-jamming module, a third anti-jamming module, and a laser diode. The power supply is connected to the direct modulation laser drive circuit through the first anti-jamming module, the first end of the second anti-jamming module is connected to the cathode of the laser diode, and the second end of the second anti-jamming module is connected to the laser diode cathode. Connect with the first end of the DC bias module. The first end of the third anti-jamming module is connected to the first end of the DC bias module, and the second end of the third anti-jamming module is connected to the second end of the DC bias module.

In one embodiment, the first anti-jamming module includes a first magnetic bead, the second anti-jamming module includes a second magnetic bead, and the third anti-jamming module includes a third capacitor.

The above-mentioned direct-tuning laser driving circuit can eliminate the asymmetrical bias caused by the laser diode load and the driving circuit by setting different parameters for the capacitors in the neutralization module by adopting separate optimization methods, thereby improving the system performance. bandwidth, thereby improving the quality of the eye diagram obtained by the system test and suppressing the jitter of the system, solving the problems of insufficient bandwidth, poor eye diagram quality and low jitter performance in the traditional technical solution.

Description of drawings

In order to illustrate the technical solutions in the embodiments of the present application more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only for the present application. In some embodiments, for those of ordinary skill in the art, other drawings can also be obtained according to these drawings without any creative effort.

1 is a circuit schematic diagram of a direct-modulated laser driving circuit provided by an embodiment of the present application;

FIG. 2 is a circuit schematic diagram of another embodiment of the neutralization module in the direct-modulated laser driving circuit shown in FIG. 1;

FIG. 3 is a circuit schematic diagram of another embodiment of the current modulation module in the direct-modulated laser driving circuit shown in FIG. 1;

4 is a circuit schematic diagram of a direct-modulated laser driving circuit provided by an embodiment of the present application;

FIG. 5 is a circuit schematic diagram of another embodiment of the current modulation module in the direct-modulated laser driving circuit shown in FIG. 1;

Fig. 6 is the circuit schematic diagram of the servo loop module in the direct modulation laser drive circuit shown in Fig. 1;

7 is a circuit schematic diagram of another embodiment of the current modulation module in the direct-modulated laser driving circuit shown in FIG. 1;

8 is a circuit schematic diagram of a second compensation unit in the direct-modulated laser driving circuit shown in FIG. 1;

FIG. 9 is a schematic circuit diagram of a direct-modulated laser driving system according to an embodiment of the second aspect of the present application;

FIG. 10 is a schematic circuit diagram of the direct modulation laser drive system shown in FIG. 9;

FIG. 11 is a system bandwidth diagram obtained after the direct modulation laser drive circuit is adjusted by asymmetric capacitance according to an embodiment of the application;

FIG. 12 is a system test eye diagram obtained after a compensation unit is added to the direct modulation laser drive circuit according to an embodiment of the present application.

Detailed ways

In order to make the purpose, technical solutions and advantages of the present application more clearly understood, the present application will be described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application, but not to limit the present application.

Please refer to FIG. 1 , which is a schematic structural diagram of a direct-modulated laser driving circuit provided by one of the embodiments of the present application. For the convenience of description, only the parts related to this embodiment are shown, and the details are as follows:

The direct modulation laser driving circuit in this embodiment is connected to the first input signal Input singal-1 and the second input signal Input singal-2, the direct modulation laser driving circuit is connected to the power supply VCC through the first anti-interference module 600, and the direct modulation laser drives The circuit is connected to the laser diode D1 , and the anode of the laser diode D1 is connected to the power supply VCC through the first anti-interference module 600 .

In one embodiment, the direct modulation laser driving circuit includes a neutralization module 100, a current modulation module 200, a DC bias module 300, a first anti-jamming module 600, and a second anti-jamming module 700, wherein the neutralization module 100 includes a capacitor C1 and capacitor C2, the current modulation module 200 includes transistors Q1 and Q2, a resistor R1, a first current sink 210 and a second current sink 220, and the DC bias module 300 includes a third current sink 310.

It should be understood that the capacitor C1 and the capacitor C2 do not need to be symmetrical, but are optimized separately, and are adjusted by setting different parameters for the capacitor C1 and the capacitor C2, so that the neutralization module can eliminate the laser diode D1 and the direct modulation laser drive circuit. The impact of the asymmetric structure caused by itself, thereby increasing the bandwidth of the system, improving the quality of the eye diagram obtained by the system test, and suppressing jitter.

It should be understood that the transistors Q1 and Q2 are three-terminal transistors, for example, a PNP type triode, an NPN type triode, a field effect transistor, a MOS transistor or an IGBT thyristor, etc., and Q1 and Q2 may be differentially symmetrical. The transistors Q1, Q2 and the type of differential pair formed by the transistors Q1, Q2 shown in FIG. 1 are only one example, and the types of transistors and differential pairs are not limited.

It should be understood that the current sink can specifically be composed of transistors, resistors and capacitors. A constant current source composed of electronic components such as inductors.

The first anti-jamming module 600 and the second anti-jamming module 700 may use devices that can filter out high-frequency noise and keep the current constant, such as magnetic beads, capacitors, and the like.

The base of the transistor Q1 is connected to the first input signal Input singal-1, the emitter of the transistor Q1 is connected to the first terminal of the resistor R1 and the first terminal of the first current sink 210, and the collector of the transistor Q1 is connected to the laser diode D1 and the laser diode D1 and the first terminal of the first current sink 210. The power supply Vcc is connected, the base of the transistor Q2 is connected to the second input signal Input singal-2, the emitter of the transistor Q2 is connected to the second end of the resistor R1 and the first end of the second current sink 220, and the collector of the transistor Q2 is connected to The cathode of the laser diode D1 is connected, the first end of the resistor R1 is connected to the emitter of the transistor Q1 and the first end of the first current sink 210, and the second end of the resistor R1 is connected to the emitter of the transistor Q2 and the second current sink 220. The first terminal is connected, and the second terminal of the first current sink 210 and the second terminal of the second current sink 220 are connected to ground.

The first end of the capacitor C1 is connected to the collector of the transistor Q1, the second end of the capacitor C1 is connected to the base of the transistor Q2, the first end of the capacitor C2 is connected to the base of the transistor Q1, and the second end of the capacitor C2 is connected to the transistor Collector connection of Q2.

The first end of the third current sink 310 is the first end of the DC bias module 300 , the first end of the DC bias module is connected to the cathode of the laser diode D1 through the second anti-interference module 700 , and the first end of the third current sink 310 is connected to the cathode of the laser diode D1 through the second anti-interference module 700 . The two terminals are the second terminal of the DC bias module 300 , the second terminal of the DC bias module 300 is grounded, and the DC bias module 300 is used to provide a DC bias current to the laser diode D1 .

Referring to FIG. 11 , FIG. 11 shows the result obtained after the circuit of this embodiment is modeled after the simulation system. It can be seen that the bandwidth of the system is significantly improved.

In the direct modulation laser drive circuit in this embodiment, different parameters are set for the capacitors in the neutralization module by adopting separate optimization methods to eliminate the asymmetrical bias caused by the laser diode load and the drive circuit, thereby improving the The bandwidth of the system is improved, the quality of the eye diagram obtained by the system test is improved, the jitter of the system is suppressed, and the problems of insufficient bandwidth, poor eye diagram quality and low jitter performance in the traditional technical solution are solved.

Please refer to FIG. 1 and FIG. 2 , in a further embodiment, the neutralization module 100 further includes a first adjustment unit 101 and a second adjustment unit 102 for adjusting and neutralizing the peak value, and the first adjustment unit 101 is connected in series with the capacitor C1 , the second adjustment unit 102 is connected in series with the capacitor C2. Capacitors C1 and C2 were added in series tuning devices to finer-tune and neutralize peak behavior, thereby improving the performance of eye diagrams and jitter in system testing.

In one embodiment, the first adjustment unit 101 includes a resistor R2, the second adjustment unit 102 includes a resistor R3, the resistor R2 is connected in series with the capacitor C1, and the resistor R3 is connected in series with the capacitor C2. In this embodiment, series resistors are added to the capacitors C1 and C2 respectively; in other embodiments, the first adjustment unit 101 and the second adjustment unit 102 may be other devices, such as inductors, capacitors, diodes, transistors, and the like.

Referring to FIG. 1 and FIG. 3 , in a further embodiment, the current modulation module 200 further includes a first alleviation unit 201 and a second alleviation unit 202 for alleviating transient spikes caused by parasitic inductance. The first terminal is connected to the first input signal Input singal-1, the second terminal of the first slowing unit 201 is connected to the base of the transistor Q1, the first terminal of the second slowing unit is connected to the second input signal Input singal-2, The second terminal is connected to the base of the transistor Q2.

It should be understood that parasitic inductance is likely to occur during wiring and vias on the printed circuit board. In this embodiment, the presence of the parasitic inductance in the direct-modulation laser driving circuit will affect the direct-modulation laser driving circuit and the devices connected to the direct-modulating laser driving circuit. Causes great harm, such as: weakening the effect of capacitors in the circuit, weakening the filtering function of the system, etc. For ease of understanding, please refer to Figure 4. Figure 4 illustrates one of the locations where parasitic inductance exists, including parasitic inductance. For the inductance BW1 and the parasitic inductance BW2, the position of the parasitic inductance in other embodiments of the present application may also refer to this figure.

In one embodiment, the first mitigation unit 201 includes an inductor L1, the second mitigation unit 202 includes an inductor L2, the first terminal of the inductor L1 is connected to the first input signal Input singal-1, and the second terminal of the inductor L1 is connected to the transistor The base of Q1, the first terminal of the inductor L2 is connected to the second input signal Input singal-2, and the second terminal of the inductor L2 is connected to the base of the transistor Q2. In other embodiments, the first alleviation unit 201 and the second alleviation unit 202 may be other devices, such as inductive devices such as magnetic beads.

By adding the mitigation units 201 and 202, the current modulation module 200 uses the blocking characteristic (Lenz's law or Faraday's law) of the inductive device itself to the current change to slow down the excessively severe instantaneous peak value caused by the parasitic inductance of the direct-modulated laser driving circuit, Thereby, the quality of the eye diagram is improved and the system jitter is suppressed.

Referring to FIG. 1 and FIG. 5 , in a further embodiment, the current modulation module 200 further includes a third mitigation unit 203 for mitigating transient spikes caused by parasitic inductance, the third mitigating unit 203 is connected in series with the resistor R1 .

In one embodiment, the third alleviation unit 203 may be composed of a device with a blocking characteristic to current changes, such as an inductor or a magnetic bead.

In this embodiment, by adding an inductance, the excessively severe instantaneous peak value caused by the parasitic inductance existing in the direct modulation laser driving circuit is slowed down by using the blocking characteristic of the inductive device itself to the current change (Lenz's law or Faraday's law), thereby improving the The quality of the eye diagram and the suppression of system jitter. This embodiment and the previous embodiment can be carried out simultaneously or independently.

Please refer to FIG. 1 and FIG. 6. In one embodiment, the direct modulation laser driving circuit further includes a servo loop module 400 for improving and fixing the voltage margin of the transistors. The first input terminal of the servo loop module 400 is connected to a preset The voltage value is connected, the second input terminal of the servo loop module 400 is connected to the center point of the resistor R1, the third input terminal of the servo loop module 400 is connected to the first input signal Input singal-1, and the fourth input terminal of the servo loop module 400 is connected to the first input signal Input singal-1. The input terminal is connected to the second input signal Inputsingal-2, the first output terminal of the servo loop module 400 is connected to the base of the transistor Q1, and the second output terminal of the servo loop module 400 is connected to the base of the transistor Q2.

In a specific application, the servo loop module 400 can use an analog negative feedback control circuit, such as a negative feedback control circuit composed of a comparator U1 and an operational amplifier U2, and the non-inverting input terminal of the comparator U1 is the servo loop module 400 The first input terminal of , the negative input terminal is the second input terminal of the servo loop module 400, the output terminal of the comparator U1 is connected to the control terminal of the operational amplifier U2, and the first input terminal of the operational amplifier U2 is the servo loop module 400. The third input end of the operational amplifier U2 is the fourth input end of the servo loop module 400, the first output end of the operational amplifier U2 is the first output end of the servo loop module 400, the The second output terminal is the second output terminal of the servo loop module 400 .

In this embodiment, a servo loop module is added to change the supply voltage of the operational amplifier of the pre-driver stage through negative feedback, so as to adjust the common-mode voltage at the output of the operational amplifier, and then control the DC bias of the base node of Q1 and Q2. The voltage value at the center of the resistor R1 is compared with a preset reference voltage REF, and the obtained voltage difference drives the operational amplifier. The output of the driver stage of the operational amplifier controls the DC bias of the base node of Q1 and Q2. For example, if the common mode voltage needs to be increased by 0.2V, the output terminal of the feedback op amp is connected to the gate of the PMOS switch connected in series with the voltage of the previous stage, and the feedback circuit will automatically adjust the drain voltage of the PMOS to increase by 0.2V. The servo loop module added in the embodiment makes the base common mode voltage of Q1 and Q2 fixed at a preset value (close to the input reference voltage of the op amp), so as to avoid the voltage margin under certain voltage, temperature, or manufacturing deviation conditions degree issue.

Referring to FIG. 1 , FIG. 7 and FIG. 12 , in one embodiment, the current modulation module 200 further includes a first compensation unit 204 for compensating for bandwidth variation, and the first compensation unit 204 is connected in series with the first current sink 210 and the first current sink 210 Bias input of two current sinks 220 .

In a specific application, the first compensation unit 204 may use a device that can cancel the DC bias, such as a bias resistor.

Figure 12 shows the eye diagram obtained by the system test using this embodiment. It can be seen that the "eye" in the eye diagram is wide open, the eye diagram is correct, and the inter-symbol crosstalk is small.

When the bias current of the current sink is adjusted up or down, it will cause the position of the pole and zero of the intermediate frequency to change, thus affecting the frequency response of the direct modulation laser drive circuit. Placing resistor R5 in series with the bias input of the current sink can compensate for the above bandwidth variation, thereby improving the quality of the eye diagram for system testing.

Referring to FIG. 1 and FIG. 8 , in one embodiment, the direct modulation laser driving circuit further includes a second compensation unit 500 for compensating for bandwidth variation, the first end of the second compensation unit 500 and the first output of the current modulation module The second end of the second compensation unit 500 is connected to the second output end of the current modulation module.

In a specific application, the second compensation unit 500 may be composed of adjustable capacitors, such as a variable capacitor array.

In this embodiment, a second compensation unit with adjustable capacitance is added between the output ends of the current modulation module, and its parameters are adjusted according to the high-frequency response of the circuit, so as to compensate for changes in the system bandwidth.

Referring to FIG. 9 , a second aspect of the present application provides a direct modulation laser system, the direct modulation laser system includes the above-mentioned direct modulation laser driving circuit, a laser diode D1, a power supply Vcc, a first anti-interference module 600, a second anti-interference module The interference module 700 and the third anti-interference module 800 .

In specific applications, the anti-jamming module can use devices that can filter out high-frequency noise and keep the current constant, such as magnetic beads and capacitors.

The power supply is connected to the direct modulation laser drive circuit through the first anti-jamming module 600, the first end of the second anti-jamming module 700 is connected to the cathode of the laser diode D1, and the second end of the second anti-jamming module 700 is connected to the DC bias module The first end of 300.

Referring to FIG. 10, in one embodiment, the first anti-jamming module 600 includes a first magnetic bead, the second anti-jamming module 700 includes a second magnetic bead 701, the third anti-jamming module 800 includes a capacitor C3, and the first magnetic bead The first end of 601 is connected to the power supply, the second end of the first magnetic bead 601 is connected to the emitter of the first transistor, the first end of the second magnetic bead 701 is connected to the cathode of the laser diode D1, and the second end of the second magnetic bead 701 is connected to the cathode of the laser diode D1. The second end is connected to the first end of the DC bias module 300 , the first end of the capacitor C3 is connected to the first end of the DC bias module, and the second end of the capacitor C3 is connected to the second end of the DC bias module.

Various embodiments are described herein for various devices, circuits, apparatus, systems, and/or methods. Numerous specific details are set forth to provide a thorough understanding of the general structure, function, manufacture, and use of the embodiments as described in the specification and illustrated in the accompanying drawings. It will be understood by those skilled in the art, however, that embodiments may be practiced without such specific details. In other instances, well-known operations, components and elements have been described in detail so as not to obscure the implementations in the specification. It will be understood by those skilled in the art that the embodiments herein and shown are non-limiting examples, and therefore, it may be appreciated that the specific structural and functional details disclosed herein may be representative and do not necessarily limit the embodiments range.

Reference throughout this specification to "various embodiments," "in an embodiment," "one embodiment," or "an embodiment," etc., means that a particular feature, structure, or characteristic described in relation to an embodiment is included in at least one in one embodiment. Thus, appearances of the phrases "in various embodiments," "in some embodiments," "in one embodiment," or "in an embodiment" in appropriate places throughout the specification are not necessarily all referring to the same implementation. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner in one or more embodiments. Thus, a particular feature, structure or characteristic illustrated or described with respect to one embodiment may be combined in whole or in part with the features, structures or characteristics of one or more other embodiments without presuming that such a combination is not illogical or No functional restrictions.

Those skilled in the art can clearly understand that, for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example. Module completion, that is, dividing the internal structure of the device into different functional units or modules to complete all or part of the functions described above. Each functional unit and module in the embodiment may be integrated in one processing unit, or each unit may exist physically alone, or two or more units may be integrated in one unit, and the above-mentioned integrated units may adopt hardware. It can also be realized in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing from each other, and are not used to limit the protection scope of the present application. For the specific working processes of the units and modules in the above-mentioned system, reference may be made to the corresponding processes in the foregoing method embodiments, which will not be repeated here.

In the foregoing embodiments, the description of each embodiment has its own emphasis. For parts that are not described or described in detail in a certain embodiment, reference may be made to the relevant descriptions of other embodiments.

In the embodiments provided in this application, it should be understood that the disclosed apparatus/terminal device and method may be implemented in other manners. For example, the apparatus/terminal device embodiments described above are only 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, such as multiple units. Or components may be combined or may be integrated into another system, or some features may be omitted, or not implemented. On the other hand, the shown or discussed mutual coupling or direct coupling or communication connection may be through some interfaces, indirect coupling or communication connection of devices or units, and may be in electrical, mechanical or other forms.

The above descriptions are only preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application shall be included in the protection of the present application. within the range.

Claims (10)

1. The utility model provides a directly transfer laser drive circuit which characterized in that, external first input signal and second input signal, directly transfer laser drive circuit is connected with the power through first anti-jamming module, directly transfer laser drive circuit is connected with laser diode, laser diode's positive pole through first anti-jamming module with the power is connected, directly transfer laser drive circuit includes:

a current modulation module including a first transistor, a second transistor, a first resistor, a first current sink, and a second current sink, wherein a base of the first transistor is connected to the first input signal, a collector of the first transistor is connected to an anode of the laser diode, a collector of the first transistor is a first output terminal of the current modulation module, a base of the second transistor is connected to the second input signal, a collector of the second transistor is connected to a cathode of the laser diode, a collector of the second transistor is a second output terminal of the current modulation module, a first end of the first resistor is connected to an emitter of the first transistor and a first end of the first current sink, and a second end of the first resistor is connected to an emitter of the second transistor and a first end of the second current sink, a second terminal of the first current sink and a second terminal of the second current sink are commonly grounded;

the first end of the first capacitor is connected with the collector of the first transistor, the second end of the first capacitor is connected with the base of the second transistor, the first end of the second capacitor is connected with the base of the first transistor, the second end of the second capacitor is connected with the collector of the second transistor, and the first capacitor and the second capacitor are adjusted by setting different parameters in a respectively independent optimization mode so as to eliminate asymmetric bias; and

the direct current bias module comprises a third current trap, the first end of the third current trap is the first end of the direct current bias module, the first end of the direct current bias module is connected to the cathode of the laser diode through the second anti-interference module, the second end of the third current trap is the second end of the direct current bias module, the second end of the direct current bias module is grounded, and the direct current bias module is used for providing direct current bias current for the laser diode.

2. The direct mode laser driver circuit of claim 1, wherein the neutralization module comprises a first adjustment unit and a second adjustment unit for adjusting the neutralization peak behavior, the first adjustment unit being in series with the first capacitor, the second adjustment unit being in series with the second capacitor.

3. The directly tuned laser driving circuit of claim 2, the first adjusting unit comprising a second resistor, the second adjusting unit comprising a third resistor, the second resistor being in series with the first capacitor, the third resistor being in series with the second capacitor.

4. The direct-tuned laser driver circuit of claim 1, wherein said current modulation module further comprises a first mitigation unit and a second mitigation unit for mitigating transient spikes caused by parasitic inductance, a first terminal of said first mitigation unit being coupled to said first input signal, a second terminal of said first mitigation unit being coupled to a base of said first transistor; the first end of the second retarding unit is connected to the second input signal, and the second end of the second retarding unit is connected to the base of the second transistor.

5. The direct mode laser driver circuit of claim 1, wherein the current modulation module further comprises a third mitigation unit to mitigate transient spikes caused by parasitic inductance, the third mitigation unit being in series with the first resistor.

6. The direct mode laser driver circuit of claim 1, further comprising a servo loop module for boosting and fixing a voltage margin of the transistor, wherein a first input of the servo loop module is connected to a predetermined voltage value, a second input of the servo loop module is connected to the first resistor center point, a third input of the servo loop module is connected to the first input signal, a fourth input of the servo loop module is connected to the second input signal, a first output of the servo loop module is connected to the base of the first transistor, and a second output of the servo loop module is connected to the base of the second transistor.

7. The direct mode laser driver circuit of claim 6, wherein the servo loop module includes a first comparator and a first operational amplifier, the positive phase input end of the first comparator is the first input end of the servo loop module, the negative phase input end of the first comparator is the second input end of the servo loop module, the output end of the first comparator is connected with the control end of the first operational amplifier, the first input end of the first operational amplifier is the third input end of the servo loop module, the second input terminal of the first operational amplifier is a fourth input terminal of the servo loop module, the first output terminal of the first operational amplifier is a first output terminal of the servo loop module, the second output end of the first operational amplifier is the second output end of the servo loop module.

8. The direct mode laser driver circuit of claim 1, wherein the current modulation module further comprises a first compensation unit to compensate for bandwidth variations, the first compensation unit being connected in series to bias inputs of the first and second current wells.

9. The direct mode laser driver circuit of claim 1, further comprising a second compensation unit to compensate for bandwidth variations, a first terminal of the second compensation unit being connected to the first output terminal of the current modulation module, and a second terminal of the second compensation unit being connected to the second output terminal of the current modulation module.

10. A directly modulated laser system, characterized in that, the directly modulated laser driving device includes the directly modulated laser driving circuit of any one of claims 1-9, a power supply, a first anti-interference module, a second anti-interference module, a third anti-interference module and a laser diode, the power supply is connected to the directly modulated laser driving circuit through the first anti-interference module, a first end of the second anti-interference module is connected to the laser diode cathode, a second end of the second anti-interference module is connected to a first end of the dc bias module.

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