CN115225156B - Feedback circuit for optical transmitter and optical transmitter - Google Patents
Feedback circuit for optical transmitter and optical transmitter Download PDFInfo
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- CN115225156B CN115225156B CN202210859371.XA CN202210859371A CN115225156B CN 115225156 B CN115225156 B CN 115225156B CN 202210859371 A CN202210859371 A CN 202210859371A CN 115225156 B CN115225156 B CN 115225156B
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/50—Transmitters
- H04B10/501—Structural aspects
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/50—Transmitters
- H04B10/516—Details of coding or modulation
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Abstract
A feedback circuit for an optical transmitter and an optical transmitter are provided. The light emitter includes: a driver for amplifying an input signal based on a gain control signal to generate a driving signal; and a modulator for generating an output optical signal by modulating the drive signal onto an input optical signal, the feedback circuit comprising: the optical splitter is used for splitting a certain proportion of optical signals from the output optical signals to serve as bypass optical signals; and a control circuit for generating the gain control signal based on a first comparison result between a peak value of the drive signal and a first reference value and a second comparison result between a peak value of the bypass optical signal and a second reference value.
Description
Technical Field
The present disclosure relates to a feedback circuit for an optical transmitter and an optical transmitter.
Background
Long-range high quality optical transmission requires that the optical transmitter be capable of providing optical signals of sufficiently high amplitude and Extinction Ratio (ER), and thus requires that the driver be capable of providing a sufficiently large output swing to drive the optical modulator. However, increasing the swing of the driver inevitably consumes higher power consumption. Therefore, to achieve the best performance of the optical interconnection system, the output swing of the driver needs to be adjusted according to the actual application environment and the system requirements.
If the adjustment of the driver output swing is achieved by joint tuning of the optical transmitter and optical receiver, a long feedback adjustment loop is required and a complex system implementation is required. Thus, a more efficient feedback circuit for an optical transmitter is desired.
Disclosure of Invention
According to an aspect of the present disclosure, there is provided a feedback circuit for an optical transmitter, the optical transmitter including: a driver for amplifying an input signal based on a gain control signal to generate a driving signal; and a modulator for generating an output optical signal by modulating the drive signal onto an input optical signal, the feedback circuit comprising: the optical splitter is used for splitting a certain proportion of optical signals from the output optical signals to serve as bypass optical signals; and a control circuit for generating the gain control signal based on a first comparison result between a peak value of the drive signal and a first reference value and a second comparison result between a peak value of the bypass optical signal and a second reference value.
According to another aspect of the present disclosure, there is provided a light emitter including: a driver for amplifying an input signal based on a gain control signal to generate a driving signal; a modulator for generating an output optical signal by modulating the drive signal onto an input optical signal; and a feedback circuit according to an embodiment of the present disclosure.
These and other aspects of the disclosure will be apparent from and elucidated with reference to the embodiments described hereinafter.
Drawings
Further details, features and advantages of the present disclosure are disclosed in the following description of exemplary embodiments, with reference to the following drawings, wherein:
fig. 1 is a schematic circuit diagram of an optical transmitter and an optical receiver in the related art;
fig. 2 is a schematic block diagram illustrating an optical transmitter and feedback circuit according to an exemplary embodiment of the present disclosure;
fig. 3 is a schematic block diagram illustrating a light emitter and feedback circuit according to a variation of an exemplary embodiment of the present disclosure;
fig. 4 is a schematic block diagram illustrating an optical transmitter and feedback circuit according to another variation of an exemplary embodiment of the present disclosure.
Detailed Description
It will be understood that, although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present disclosure.
Spatially relative terms, such as "under …," "under …," "lower," "under …," "over …," "upper," and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that these spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "under" or "beneath" other elements or features would then be oriented "over" the other elements or features. Thus, the exemplary terms "below …" and "below …" may encompass both orientations above … and below …. Terms such as "before …" or "before …" and "after …" or "followed by" may similarly be used, for example, to indicate the order in which light passes through the elements. The device may be oriented in other ways (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. In addition, it will also be understood that when a layer is referred to as being "between" two layers, it can be the only layer between the two layers, or one or more intervening layers may also be present.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items, and the phrase "at least one of a and B" includes a only, B only, and both a and B.
It will be understood that when an element or layer is referred to as being "on," "connected to," "coupled to," or "adjacent to" another element or layer, it can be directly on, connected to, coupled to, or adjacent to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being "directly on," "directly connected to," "directly coupled to," or "directly adjacent to" another element or layer, there are no intervening elements or layers present. However, in no event "on …" or "directly on …" should be construed as requiring one layer to completely cover an underlying layer.
Embodiments of the present disclosure are described herein with reference to schematic illustrations (and intermediate structures) of idealized embodiments of the present disclosure. As such, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. Thus, embodiments of the present disclosure should not be construed as limited to the particular shapes of regions illustrated herein but are to include deviations in shapes that result, for example, from manufacturing. Thus, the regions illustrated in the figures are schematic in nature and their shapes are not intended to illustrate the actual shape of a region of a device and are not intended to limit the scope of the present disclosure.
Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and/or the present specification and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
Long-range high quality optical transmission requires that the optical transmitter be capable of providing optical signals of sufficiently high amplitude and Extinction Ratio (ER), and thus requires that the driver be capable of providing a sufficiently large output swing to drive the optical modulator. However, increasing the swing of the driver inevitably consumes higher power consumption. Therefore, to achieve the best performance of the optical interconnection system, the output swing of the driver needs to be adjusted according to the actual application environment and the system requirements.
According to the related art, the adjustment of the driver output swing is often achieved by joint debugging of the optical transmitter and the optical receiver. Fig. 1 is a schematic circuit diagram of a system 100 composed of an optical transmitter 110 and an optical receiver 120 in the related art. As shown in fig. 1, the optical transmitter 110 may include a driver 111, a modulator 112, and an analog-to-digital converter (DAC) 113. The optical receiver 120 may include an optical-to-electrical converter 121, an analog-to-digital converter (ADC) 122, and a Digital Signal Processor (DSP) 123. The photoelectric converter 121 may include a Photodetector (PD) and a transimpedance amplifier (TIA).
As shown in fig. 1, at the light emitter 110 side, a driver 111 amplifies an input signal D in Generating a drive signal D out To drive modulator 112. The modulator 112 may be a Mach-Zehnder (MZ) modulator. Modulator 112 drives signal D out Modulated to optical input signal OPT in On, then outputting the modulated optical signal OPT out . Optical signal OPT out After being transmitted through the optical fiber 130, the optical fiber reaches the optical receiver 120, and then passes through the photoelectric converter 121, for example, through the photoelectric converterThe detector and transimpedance amplifier convert the optical signal into an electrical signal. The analog electrical signal received at the optical receiver 120 is converted into a digital signal by the ADC 122, and is then calculated by the Digital Signal Processor (DSP) 123 to obtain an optical signal to noise ratio (OSNR). In order to achieve driver output swing adjustment, the calculated OSNR is compared to the system requirements. And if the OSNR of the light receiving end is lower than the target requirement, regulating and controlling the output swing control DAC of the transmitting end to determine to increase the output swing of the driver, so that the optimal OSNR is realized.
However, according to such related art, joint debugging of the transmitter and the receiver is required, a feedback regulation loop is long, and a required system is complex to implement, and it is difficult to achieve an effect of timely response. Furthermore, such a scheme only considers adjusting the output swing of the driver to achieve the performance sweet spot.
Exemplary embodiments of the present disclosure will be described in detail below, which may be used to advantage for a number of reasons, such as to alleviate or mitigate these undesirable side effects.
Fig. 2 is a schematic circuit diagram illustrating a system 200 comprised of an optical transmitter and a feedback circuit according to an exemplary embodiment of the present disclosure.
Referring to fig. 2, the optical transmitter may include a driver 210 and a modulator 220. The driver 210 may be configured to pair the input signal D based on the gain control signal in Amplifying to generate a driving signal D out . Modulator 220 may be used to control the driving signal D by applying the driving signal D out Modulated to an input optical signal OPT in Generating an output optical signal OPT out . In one example, the modulator may be a MZ modulator. The modulator may also be other modulators, modulation circuits, or optical output circuits capable of generating modulated optical signals as would be understood by one skilled in the art, and the disclosure is not limited thereto.
It will be appreciated that the light emitters and feedback circuits shown herein may be referred to collectively as a feedback adjustment system, and that the feedback circuits may be produced, arranged, and separated from the light emitters. In addition, although it is described above that the optical transmitter may include the driver 210 and the modulator 220, the whole formed of the driver, the modulator and the feedback circuit may be integrally referred to as an optical transmitter. It will be appreciated that the present disclosure is not limited in this respect.
With continued reference to fig. 2, the feedback circuit may include a beam splitter 230 and a control circuit 240. The optical splitter 230 may be configured to split a proportion of the optical signal from the output optical signal as a bypass optical signal. The control circuit 240 may be configured to generate the gain control signal based on a first comparison result between the peak value of the drive signal and a first reference value and a second comparison result between the peak value of the bypass optical signal and a second reference value. For example, the gain control signal may be a gain control voltage signal V SW . Alternatively, as will be appreciated by those skilled in the art, the gain control signal may be other signals suitable for controlling the gain of the driver 210, including but not limited to analog signals (e.g., current signals), digital signals, and the like.
Those skilled in the art will appreciate that the control circuit 240 may be implemented in any known or future technology. The control circuit may be implemented in logic circuits, analog circuits, or a combination thereof, and the present disclosure is not limited thereto. Examples of control circuit 240 include, but are not limited to, a general purpose processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof.
In accordance with one or more embodiments of the present disclosure, a feedback circuit, circuitry, and control method integrated at the transmit end that automatically adjusts the driver output swing are provided. Specifically, according to the driver output swing feedback adjusting circuit or method disclosed by the disclosure, the gain of the driver can be feedback controlled by detecting the output swing of the driver and the amplitude of the optical signal output by the MZ modulator, so that the purpose of adjusting the driver output swing is achieved.
The first reference value may be based on a transistor withstand voltage value of the driver. For example, according to some embodiments, the first reference value may be positively correlated to a transistor withstand voltage value of the driver. According to some alternative embodiments, in case the first reference value is a voltage value, the first reference value may be equal to or slightly higher than a transistor withstand voltage value of the driver. According to other embodiments, the first reference value may depend at least in part on the withstand voltage value or other tolerance value of other elements of the drive, and may optionally vary depending on the type of drive or element thereof, the length of operation, the life cycle.
The second reference value may be based on an optical output signal amplitude requirement of an optical link in which the optical transmitter is located. For example, according to some embodiments, the second reference value is positively correlated with a minimum optical output signal amplitude required for an optical link in which the optical transmitter is located. As a specific non-limiting example, where the second reference value is an optical signal amplitude, the second reference value may be approximately equal to the minimum optical output signal amplitude. As another specific non-limiting example, where the second reference value is a voltage value, it may be positively correlated with the minimum optical output signal amplitude. In other embodiments, the second reference value may also be based on an average optical output signal amplitude, a maximum optical output signal amplitude, an optical output signal amplitude range, etc., as required by the optical link, and the disclosure is not limited thereto.
In the scenario where a first reference value is based on the transistor withstand voltage value of the driver and a second reference value is based on the optical output signal amplitude requirement of the optical link in which the optical transmitter is located, according to some embodiments, the control circuit is configured to adjust the gain control signal such that the peak value of the drive signal is lower (or not higher) than the first reference value and the peak value of the bypass optical signal is higher (or higher) than the second reference value. According to such an embodiment, the output swing of the driver can be adjusted on the premise of ensuring the withstand voltage reliability of the driver transistor, thereby making it possible to satisfy both the requirements of long-distance transmission and long-term operation reliability of the light emitter.
According to other embodiments, the control circuit may take different logic. For example, where the second reference value indicates a maximum optical output signal amplitude required by the optical link, the logic of the control circuit may be such that the peak value of the bypass optical signal is below (or below or equal to) the second reference value, and the disclosure is not limited thereto.
A schematic block diagram of a light emitter and feedback circuit of a variation of an exemplary embodiment of the present disclosure is described below with respect to fig. 3. As shown in fig. 3, the feedback regulation system may include a driver, a modulator, and a driver swing feedback circuit. As described above, the driver swing feedback circuit and the optical transmitter may be regarded as separate circuits, respectively, or the whole formed of the driver, the modulator, and the feedback circuit may be integrally referred to as an optical transmitter, and the present disclosure is not limited thereto.
Next, for convenience of description, the light emitter part and the feedback circuit part will be described separately, but it will be understood that this will not constitute a limitation of the present disclosure. In such an example, the feedback circuit may include a driver 310 and a modulator 320, and the feedback circuit portion may include a beam splitter 330 and a control circuit 340. Driver 310 outputs input signal D in Amplifying the output driving signal D out For driving modulator 320. The output swing of driver 310 is defined by signal V SW Control, change V SW The output swing of the driver 310 may be changed. Modulator 320 is for receiving an input optical signal OPT in And will drive signal D out Modulated to an input optical signal OPT in Thereby generating an output optical signal OPT out . The feedback circuit is used for detecting the driving signal D out The amplitude and MZ modulator outputting an optical signal OPT out Amplitude of output driver swing control voltage V SW Thereby adjusting the driving signal D out Is a swing of (c).
The same reference numerals as in fig. 2 denote similar elements, and a repetitive description of the structure or function thereof will be omitted herein.
As shown in fig. 3, according to such an embodiment, the control circuit 340 may include a first detection circuit 341, a second detection circuit 342, a first comparator 343, a second comparator 344, and a feedback controller 345. The first detection circuit 341 may be configured to detect a peak value of the driving signal. Second detectionThe circuit 342 may be configured to detect a peak of the bypass optical signal. The first comparator 343 may be configured to compare a peak value of the driving signal with the first reference value and output a first output voltage indicating the first comparison result. The second comparator 344 may be configured to compare a peak value of the bypass optical signal with the second reference value and output a second output voltage indicative of the second comparison result. The feedback controller 345 may be configured to generate the gain control signal (e.g., gain control voltage signal V) based on the first output voltage and the second output voltage SW )。
According to some embodiments, the first detection circuit 341 may include a peak detector, which may be referred to herein as a first peak detector. The first peak detector may detect the driver output signal D out Output the corresponding peak voltage V PK1 . In such an embodiment, the first comparator 343 may also be referred to as a first reference voltage comparator, and the present disclosure is not limited thereto. In such an embodiment, the first comparator 343 may compare V PK1 With a preset or received reference voltage V REF1 And comparing and outputting a comparison result. Reference voltage V REF1 The (or other form of reference signal) may be preset (e.g., pre-stored) or may be dynamically generated (e.g., by the first comparator) or dynamically received (e.g., by other circuit portions or even by other circuits or devices), e.g., based on trigger conditions or periodically, and the disclosure is not limited in this regard. As an example, the control circuit 340 or the feedback controller 345 may be configured to compare the first reference voltage V of the first comparator 343 according to the voltage protection requirement of the driver output pipe REF1 Set as drive signal D out The magnitude of the restriction.
In other embodiments, the first detection circuit 341 may also include other detection circuits known to those skilled in the art that can detect the magnitude or amplitude of the driving signal, and may take various forms (e.g., an optical signal, a current signal, a digital signal, etc.) to output the peak value of the driving signal, and the present disclosure is not limited thereto.
According to some embodiments, the second detection circuit 342 may include a photoelectric converter (O/E) 3421 and a second peak detector 3422. The photoelectric converter can convert the output optical signal of a modulator into an electric signal V MON . In such an embodiment, the opto-electronic converter 3421 may be used to convert the bypass optical signal to a voltage signal V MON . A second peak detector 3422 may be used to detect the voltage signal V MON Peak value V of (2) PK2 As the peak value of the bypass optical signal, and the peak value V of the voltage signal can be set PK2 Output to the second comparator 344 for comparison.
It will be appreciated that in such an embodiment, the second comparator 344 may also be referred to as a second reference voltage comparator. In such an embodiment, the second comparator 344 may compare V PK2 With a preset or received reference voltage V REF2 And comparing and outputting a comparison result. Reference voltage V REF1 The (or other form of reference signal) may be preset (e.g., pre-stored) or may be dynamically generated (e.g., generated by a second comparator) or dynamically received (e.g., generated by other circuit portions or even by other circuits or devices), e.g., based on trigger conditions, and the disclosure is not limited in this regard. For example, in other embodiments, the second detection circuit may output peaks of the optical signal in other forms (e.g., optical signal, current signal, digital signal, etc.), and the second comparator 344 may compare the peaks so output with corresponding second reference values (which may also take various forms of analog signal or digital signal, etc.). Alternatively, instead of the second detection circuit 342 including the photoelectric converter 3421, the second comparator may include a photoelectric converter or other conversion circuit or the like. It is to be understood that the present disclosure is not so limited.
As one non-limiting example, the control circuit 340 or feedback controller 345 may be configured to output the signal OPT in accordance with the desired light of the optical interconnect link out Amplitude setting the second reference voltage V REF2 。
The feedback controller 345 may also be referred to as a driveThe controller swing feedback controller, and generating the gain control signal may include outputting a driver swing control voltage V based on a comparison output of two comparators (e.g., a first reference voltage comparator and a second reference voltage comparator) SW To adjust the output swing of the driver. As a specific non-limiting example, the step of generating or adjusting the gain control signal may comprise an iterative adjustment step of the gain control signal, for example. For example, the feedback controller 345 may be configured (e.g., pre-stored or the default generation may be in accordance with predetermined settings) with an initial V SW Values. The feedback controller 345 detects the amplitude of the optical signal output from the modulator through a second detection circuit, and compares the detected peak value with a second reference value (e.g., reference voltage V REF2 For example a preset reference voltage V REF2 ) Compare and if the peak is found to be below V REF2 Then increase V SW The value is higher than V REF2 Then decrease V SW Values. The output optical signal amplitude reaches a preset value through multiple iterations of the driver swing feedback controller. In the iterative process, the first detection circuit can detect the output swing of the driver in real time if the peak voltage V is output PK1 Higher than a preset value V REF1 It is stated that the driver output amplitude reaches a maximum value, thereby avoiding a continued increase.
According to some embodiments, the photoelectric converter may comprise a photodetector for converting the bypass optical signal into a current signal; and a transimpedance amplifier for converting the current signal to the voltage signal.
A schematic block diagram 400 of a light emitter and feedback circuit of a variation of an exemplary embodiment of the present disclosure is described below with respect to fig. 4.
As shown in fig. 4, the feedback conditioning system of the optical transmitter and feedback circuit may include a driver 410, a modulator 420, an optical splitter 430, and a control circuit 440.
The driver 410 may be used to input the signal D in Amplifying and outputting a driving signal D out . Drive signal D out Is passed byAdjusting the driver gain implementation. The magnitude of the driver gain may be determined by the voltage signal V SW And (5) controlling. One end of the output of the driver is connected with the input of the modulator, and the other end is connected with the control circuit.
The modulator 420 outputs the driving signal D from the driver 410 out Modulated to an input optical signal OPT in And then outputs the modulated optical signal to the beam splitter 430. The optical splitter 430 may include an input, a first output, and a second output. An input of the optical splitter 430 may be adapted to receive the output optical signal and a first output may be adapted to output the bypass optical signal, e.g. connected to a control circuit 440 for detecting the optical signal amplitude. The second output end can be used for optically coupling to an external optical transmission medium, such as an optical fiber or an optical waveguide, to output an optical signal OPT out . The splitting ratio of the splitter may be adjusted according to actual needs, for example, to distribute 10% of the power of the light to the control circuit, and the present disclosure is not limited thereto.
The control circuit 440 may include a first detection circuit 441, a second detection circuit 442, a first comparator 443, a second comparator 444, and a feedback controller 445.
The second detection circuit 442 may include a Photodetector (PD) 4421, a transimpedance amplifier (TIA) 4422, and a peak detector 4423.
According to such an embodiment, the feedback controller 445 may include a swing controller 4451 and a first digital-to-analog converter DAC1. Swing controller 4451 may be configured to generate a gain control digital signal SW based on the first output voltage and the second output voltage. The first digital-to-analog converter DAC1 may be used to generate the gain control signal based on the gain control digital signal.
As shown in fig. 4, the feedback controller 445 may include a first reference voltage comparator (U1), a second reference voltage comparator (U2), a first analog-to-digital converter (DAC 1), a second analog-to-digital converter (DAC 2), and a swing controller 4451.
The photodetector 4421 and the transimpedance amplifier 4422 may also be one example of the photoelectric converter 3421 in fig. 3. The input of the photoelectric detector 4421 is connected with one end output of the beam splitter, and the output of the photoelectric detector 4421The input of the transimpedance amplifier is connected. One implementation of photodetector 4421 is a photodiode employing a PIN structure. Photodetector 4421 may also take other implementations known to those skilled in the art, and the disclosure is not limited thereto. The photodetector 4421 is configured to convert the detected light signal into a current signal. The output of the transimpedance amplifier is connected to a second reference voltage comparator. The transimpedance amplifier 4422 may be implemented by an amplifier parallel resistor, the gain of which may be adjusted by adjusting the parallel resistor. The transimpedance amplifier 4422 may be used to convert the current signal output by the photodetector 4421 into a voltage signal and amplify it to a suitable amplitude to output a voltage V MON 。
An input of the first detection circuit 441 may be connected to an output of the driver 410 for detecting the driving signal D out Output the corresponding peak voltage V PK1 . The input end of the second detection circuit is connected to the output end of the transimpedance amplifier 4422 for detecting V MON Output peak voltage V PK2 。
As a specific example, the first reference voltage comparator U1 may compare V PK1 With a preset reference voltage V REF1 Comparison results CMP1 are produced. V (V) PK1 Input to the positive terminal, V, of the reference voltage comparator U1 REF1 To the negative terminal of the reference voltage comparator U1. When the output signal CMP1 of the reference voltage comparator U1 is logic high, it represents V PK1 Greater than V REF1 The amplitude of the driving signal is larger than a preset value; conversely, if the output signal CMP1 is logic low, V is represented PK1 Less than V REF1 The drive signal amplitude is less than the preset value. Similarly, the second reference voltage comparator U2 may compare V PK2 With a preset reference voltage V REF2 Comparison results CMP2 are produced. If the output signal CMP2 is logic high, it represents V PK2 Greater than V REF2 The amplitude of the optical signal is larger than a preset value; if the output signal CMP2 is logic low, it represents V PK2 Less than V REF2 The drive signal amplitude is less than the preset value. It is to be understood that the above is merely an example, and that the present disclosure is notOther logic or circuit configurations are also possible, as are the limitations.
The first analog-to-digital converter DAC1 may also be referred to as a reference voltage DAC for generating a reference voltage V based on the digital signal REF output by the swing controller 4451 REF1 And V REF2 . V as previously described REF1 Can indicate the driving signal D out Maximum amplitude of oscillation, V REF2 The minimum value of the optical signal amplitude may be indicated, but the disclosure is not limited thereto.
The second analog-to-digital converter DAC 2 may also be referred to as a swing DAC for generating a swing control voltage V from the digital signal SW output from the swing controller 4451 SW Thereby controlling the output swing of driver 410.
The swing controller 4451 may generate a swing control digital signal SW based on the received logic signals CMP1 and CMP2. If CMP1 = 0, it represents that the drive signal swing is below the preset value, the components (e.g., transistors) of the driver 410 are in the normal operating amplitude and withstand voltage acceptable range. If CMP1 = 1, it represents that the driving signal swing is higher than or equal to the preset value, and the driver 410 transistor exceeds the tolerable voltage range, so that the driving signal swing needs to be reduced. For the CMP2 signal, if CMP 2=0, it represents that the optical signal swing is lower than the preset value, the driver 410 swing needs to be increased, and the optical output signal amplitude needs to be increased. If CMP2 = 1, it represents that the optical signal swing is higher than or equal to the preset value, and the output optical signal amplitude meets the optical link requirement. Thus, the swing controller may adjust the swing control digital signal SW so that the drive signal swing satisfies both CMP1 = 0 and CMP2 = 1. It is to be understood that the above is merely an example, and that the present disclosure is not limited thereto, and other logic configurations or circuit configurations are also possible.
In accordance with one or more embodiments of the present disclosure, a light emitter is also disclosed. The optical transmitter may comprise a driver, a modulator. The driver may be configured to amplify the input signal based on the gain control signal to generate the drive signal. The modulator may be used to generate the output optical signal by modulating the drive signal onto the input optical signal. The optical transmitter may further comprise a feedback circuit according to one or more embodiments of the present disclosure.
According to one or more embodiments of the present disclosure, the amplitude of the driver output drive signal and the amplitude of the modulator output optical signal can be detected at the light emitter end by a control circuit, thereby controlling the output swing of the driver. Therefore, the problem that the output swing of the driver cannot be adjusted on the premise of guaranteeing the voltage withstand reliability of the driver transistor in the related art is solved.
According to one or more embodiments of the present disclosure, the reliability of the long-term operation of the driver can be ensured by the driver transistor withstand voltage protection circuit constituted by the first detection circuit and the first reference voltage comparator.
According to one or more embodiments of the present disclosure, the complexity of transmitter and receiver joint debugging can be reduced by integrating a control circuit at the light emitter end, thereby realizing automatic adjustment of the driver output swing.
According to one or more embodiments of the present disclosure, the output swing of the driver can be adjusted to achieve the best performance on the premise of guaranteeing the voltage withstanding reliability of the driver transistor, the maximum optical signal amplitude output can be achieved, and the requirements of long-distance transmission and long-term working reliability are considered.
While the disclosure has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative and schematic and not restrictive; the present disclosure is not limited to the disclosed embodiments. Variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed subject matter, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps than those listed and the indefinite article "a" or "an" does not exclude a plurality, the term "a" or "an" means two or more, and the term "based on" is to be interpreted as "based at least in part on". The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.
Claims (9)
1. A feedback circuit for an optical transmitter, the optical transmitter comprising: a driver for amplifying an input signal based on a gain control signal to generate a driving signal; and a modulator for generating an output optical signal by modulating the drive signal onto an input optical signal, the feedback circuit comprising:
the optical splitter is used for splitting a certain proportion of optical signals from the output optical signals to serve as bypass optical signals; and
a control circuit for generating the gain control signal based on a first comparison result between a peak value of the drive signal and a first reference value and a second comparison result between a peak value of the bypass optical signal and a second reference value,
wherein the control circuit is configured to adjust the gain control signal such that a peak value of the drive signal is below the first reference value and a peak value of the bypass optical signal is above or equal to the second reference value, wherein the first reference value is positively correlated with a transistor withstand voltage value of the driver, and wherein the second reference value is positively correlated with a minimum optical output signal amplitude required by an optical link in which the optical transmitter is located.
2. The feedback circuit of claim 1, wherein the control circuit comprises:
a first detection circuit for detecting a peak value of the drive signal;
a second detection circuit for detecting a peak value of the bypass optical signal;
a first comparator for comparing a peak value of the driving signal with the first reference value and outputting a first output voltage indicating the first comparison result;
a second comparator for comparing a peak value of the bypass optical signal with the second reference value and outputting a second output voltage indicating the second comparison result; and
and a feedback controller for generating the gain control signal based on the first output voltage and the second output voltage.
3. The feedback circuit of claim 2, wherein the first detection circuit comprises a first peak detector.
4. The feedback circuit of claim 2, wherein the second detection circuit comprises:
an optoelectronic converter for converting the bypass optical signal into a voltage signal; and
and a second peak detector for detecting a peak value of the voltage signal as a peak value of the bypass optical signal.
5. The feedback circuit of claim 4, wherein the photoelectric converter comprises:
a photodetector for converting the bypass optical signal into a current signal; and
and a transimpedance amplifier for converting the current signal to the voltage signal.
6. The feedback circuit of claim 2, wherein the feedback controller comprises:
a swing controller for generating a gain control digital signal based on the first output voltage and the second output voltage; and
a first digital-to-analog converter for generating the gain control signal based on the gain control digital signal.
7. The feedback circuit of claim 6, wherein the swing controller is further configured to generate at least one reference value setting signal, the at least one reference value setting signal configured to set the first reference value and the second reference value; and is also provided with
Wherein the feedback controller further comprises a second digital-to-analog converter for generating the first reference value and the second reference value based on the at least one reference value setting signal.
8. The feedback circuit of any of claims 1-7, wherein the optical splitter comprises:
the input end is used for receiving the output optical signal;
the first output end is used for outputting the bypass optical signal; and
and the second output end is used for being optically coupled to an external optical transmission medium.
9. A light emitter, comprising:
a driver for amplifying an input signal based on a gain control signal to generate a driving signal;
a modulator for generating an output optical signal by modulating the drive signal onto an input optical signal; and
the feedback circuit according to any one of claims 1-8.
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Citations (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS58158986A (en) * | 1982-03-17 | 1983-09-21 | Mitsubishi Electric Corp | Drive circuit for laser diode |
| JPH05224162A (en) * | 1992-02-04 | 1993-09-03 | Nec Corp | Light transmitting circuit |
| JPH05343788A (en) * | 1992-04-06 | 1993-12-24 | Matsushita Electric Ind Co Ltd | Optical fiber amplifier and optical signal transmission system |
| EP1130817A2 (en) * | 2000-02-03 | 2001-09-05 | Agere Systems Optoelectronics Guardian Corporation | Optical modulator including a self optimized RF input driver |
| JP2006060288A (en) * | 2004-08-17 | 2006-03-02 | Totoku Electric Co Ltd | Optical signal transmitter, optical signal receiver, and optical communication device for image transmission |
| CN200950576Y (en) * | 2006-09-12 | 2007-09-19 | 普诚科技股份有限公司 | Automatic gain control circuit |
| CN102035596A (en) * | 2009-09-25 | 2011-04-27 | 中兴通讯股份有限公司 | Method and device for amplifying and dynamically adjusting optical signals |
| CN104137443A (en) * | 2011-12-02 | 2014-11-05 | 塞姆泰克股份有限公司 | Closed loop optical modulation amplitude control |
| CN104300360A (en) * | 2014-10-16 | 2015-01-21 | 浙江大学 | Device and method for improving wavelength stability of superluminescent diode light source |
| CN104426611A (en) * | 2013-08-27 | 2015-03-18 | 塞姆泰克股份有限公司 | Closed loop optical modulation amplitude control |
| CN105027471A (en) * | 2012-12-28 | 2015-11-04 | 协同微波公司 | Self-injection locking phase-locked loop optoelectronic oscillator |
| CN106571787A (en) * | 2016-11-13 | 2017-04-19 | 天津大学 | Digital-analog hybrid automatic gain control amplifier |
| CN110620617A (en) * | 2018-12-27 | 2019-12-27 | 科大国盾量子技术股份有限公司 | Driving device for DFB laser in quantum key distribution |
| CN112913160A (en) * | 2018-10-30 | 2021-06-04 | 日本电气株式会社 | Optical transmitter and optical transmitting method |
| CN113098616A (en) * | 2021-03-30 | 2021-07-09 | 杭州太明科技有限公司 | Control apparatus for light source driver in optical communication transmitter and control method thereof |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3881270B2 (en) * | 2002-03-26 | 2007-02-14 | 富士通株式会社 | Drive control device and drive control method for optical modulator |
| TWM307917U (en) * | 2006-08-22 | 2007-03-11 | Princeton Technology Corp | Auto gain control circuit |
| US8831059B2 (en) * | 2011-02-07 | 2014-09-09 | Mitsubishi Electric Corporation | Laser diode driver circuit |
| JP7024234B2 (en) * | 2017-07-18 | 2022-02-24 | 富士通株式会社 | Optical transmitter and control method of optical transmitter |
-
2022
- 2022-07-20 CN CN202210859371.XA patent/CN115225156B/en active Active
Patent Citations (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS58158986A (en) * | 1982-03-17 | 1983-09-21 | Mitsubishi Electric Corp | Drive circuit for laser diode |
| JPH05224162A (en) * | 1992-02-04 | 1993-09-03 | Nec Corp | Light transmitting circuit |
| JPH05343788A (en) * | 1992-04-06 | 1993-12-24 | Matsushita Electric Ind Co Ltd | Optical fiber amplifier and optical signal transmission system |
| EP1130817A2 (en) * | 2000-02-03 | 2001-09-05 | Agere Systems Optoelectronics Guardian Corporation | Optical modulator including a self optimized RF input driver |
| JP2006060288A (en) * | 2004-08-17 | 2006-03-02 | Totoku Electric Co Ltd | Optical signal transmitter, optical signal receiver, and optical communication device for image transmission |
| CN200950576Y (en) * | 2006-09-12 | 2007-09-19 | 普诚科技股份有限公司 | Automatic gain control circuit |
| CN102035596A (en) * | 2009-09-25 | 2011-04-27 | 中兴通讯股份有限公司 | Method and device for amplifying and dynamically adjusting optical signals |
| CN104137443A (en) * | 2011-12-02 | 2014-11-05 | 塞姆泰克股份有限公司 | Closed loop optical modulation amplitude control |
| CN105027471A (en) * | 2012-12-28 | 2015-11-04 | 协同微波公司 | Self-injection locking phase-locked loop optoelectronic oscillator |
| CN104426611A (en) * | 2013-08-27 | 2015-03-18 | 塞姆泰克股份有限公司 | Closed loop optical modulation amplitude control |
| CN104300360A (en) * | 2014-10-16 | 2015-01-21 | 浙江大学 | Device and method for improving wavelength stability of superluminescent diode light source |
| CN106571787A (en) * | 2016-11-13 | 2017-04-19 | 天津大学 | Digital-analog hybrid automatic gain control amplifier |
| CN112913160A (en) * | 2018-10-30 | 2021-06-04 | 日本电气株式会社 | Optical transmitter and optical transmitting method |
| CN110620617A (en) * | 2018-12-27 | 2019-12-27 | 科大国盾量子技术股份有限公司 | Driving device for DFB laser in quantum key distribution |
| CN113098616A (en) * | 2021-03-30 | 2021-07-09 | 杭州太明科技有限公司 | Control apparatus for light source driver in optical communication transmitter and control method thereof |
Non-Patent Citations (1)
| Title |
|---|
| 基于增益可控运放的脉冲信号自动增益控制;黄勇;汤彬;牛鹏俊;景华;;探测与控制学报(第01期);全文 * |
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