A mixed frequency multi-band DFB laser driving system

Abstract

The application discloses a kind of DFB laser control drive systems in the technical field of semiconductor laser, including drive circuit, radio frequency selection output ware, optical filter module, main control module, current filter module, monitoring module and DFB laser group, drive circuit is connected with DFB laser group and radio frequency selection output ware, DFB laser group is connected with monitoring module, monitoring module is connected with radio frequency selection output ware, radio frequency selection output ware is connected with optical filter module and main control module, main control module is connected with current filter module.The system of the application realizes accurate stable drive control to different wavelength DFB laser, can selectively open the laser signal output channel of a road;First, filter out the interference wavelength and noise in optical signal, remove low-frequency signal in output signal again, ensure the accuracy of output signal;Realize the data communication of circuit system and host computer, can display various data of circuit system in real time, and promptly analyze and process.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor laser technology, specifically relating to a mixing multi-band DFB laser driving system. Background Technology

[0002] The rapid development of fiber optic communication technology in recent years has demanded that laser sources possess high stability and reliability in high-capacity, long-distance fiber optic communication systems. Among these, semiconductor distributed feedback lasers have become one of the most promising optical communication light source devices due to their high integration, high reliability, and high stability, and have been widely used and researched.

[0003] In tunable semiconductor laser absorption spectroscopy, to drive the laser, a superimposed sinusoidal signal is often used to change the driving current and modulate the output wavelength of the semiconductor laser. However, the upper limit of the superimposed sinusoidal frequency is low, which leads to a decrease in system sensitivity. At the same time, the traditional laser driving circuit is limited to a single target, which can only drive a DFB laser with a single wavelength and power. Moreover, the current fluctuation of the driving circuit is large, the temperature drift is serious, the response speed is slow, and the optical signal output by the laser often carries interference optical signals, resulting in high noise floor, which is not conducive to subsequent precision measurement. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the purpose of this invention is to provide a mixed-frequency multi-band DFB laser driving system to solve the problems mentioned in the background art.

[0005] The objective of this invention can be achieved through the following technical solutions:

[0006] A DFB laser control and drive system includes a drive circuit, an RF selector output unit, an optical filter module, a main control module, a current filter module, a monitoring module, and a DFB laser array. The drive circuit is connected to the DFB laser array and the RF selector output unit. The DFB laser array is connected to the monitoring module. The monitoring module is connected to the RF selector output unit. The RF selector output unit is connected to the optical filter module and the main control module. The main control module is connected to the current filter module.

[0007] The main control drive circuit mixes and adds the input low-frequency sawtooth wave signal with a high-frequency sine wave signal output from the RF selector output unit to modulate the wavelength of the DFB laser, generating the drive current required by the DFB laser to drive the DFB laser to output an optical signal. The RF selector output unit outputs two high-frequency sine wave signals, one as the modulation signal for the drive circuit and the other as the synchronization signal for the main control module. At the same time, the RF selector output unit selects the channel of the input laser. The optical filtering module is controlled by a microcontroller and uses the method of adjusting and switching the laser scanning to filter out the input interference band and other noise, outputting only a single band of mixed laser signal at any time. The main control module uses the high-frequency sine wave synchronization signal to synchronize the laser signal, obtaining a complete signal within one cycle. The current filtering module performs high-frequency filtering on the signal processed by the main control module to remove the low-frequency signal components in the input signal. The filtered high-frequency signal is finally output as the output signal.

[0008] Preferably, the driving circuit includes a low-pass filter, a mixer, and a voltage-controlled constant current power supply.

[0009] Preferably, the mixer is a non-inverting input summation circuit composed of integrated amplifiers.

[0010] Preferably, the voltage-controlled constant current source includes an operational amplifier and a field-effect transistor.

[0011] Preferably, the radio frequency selection output unit includes a high-frequency sine wave generator circuit and an analog multiplexer.

[0012] Preferably, the electrical filtering module includes a high-pass filter.

[0013] Preferably, the monitoring module includes an analog-to-digital converter and an OLED screen.

[0014] The beneficial effects of this invention are:

[0015] 1. The present invention realizes the driving control of DFB lasers with different center wavelengths by a driving circuit. By using wavelength modulation, a sine wave signal with a frequency of up to several GHz can be superimposed on a low-frequency sawtooth wave scanning signal to generate a driving current. It can be equipped with multiple DFB lasers with wavelength range of 1350-1850nm, and achieve precise and stable driving control of DFB lasers with different wavelengths. Furthermore, by using an RF selection output device, a laser signal output channel of a certain path can be selectively opened for multiple laser information.

[0016] 2. The system of the present invention addresses optical and electrical noise during operation by employing optical and electrical filtering. First, it filters out interfering wavelengths and noise in the optical signal, outputting only a single-band mixed laser signal at any given time. After processing the optical signal, it performs electrical filtering again to remove low-frequency signals from the output signal, thus ensuring the accuracy of the output signal.

[0017] 3. The system of this invention realizes data communication between the circuit system and the host computer. Through the main control module, the host computer can display various data of the circuit system in real time and perform timely analysis and processing. At the same time, the host computer can flexibly adjust the current type, magnitude and direction of the input laser control driving circuit system according to different application scenarios. The circuit monitoring module realizes real-time monitoring of the circuit system, which is convenient for later maintenance. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the system structure of the present invention;

[0020] Figure 2 This is a schematic diagram of the driving circuit in this invention;

[0021] Figure 3 This is a circuit diagram showing the connection of the mixer circuit in this invention;

[0022] Figure 4 This is the circuit diagram of the constant current voltage-controlled source in this invention;

[0023] Figure 5 This is a diagram showing how multiple lasers in this invention are selected and output via a radio frequency selector.

[0024] Figure 6 This is a diagram showing the gas waveform scanned by a DFB laser driven by the system of this invention, which has six wavelengths. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] Please see Figures 1 to 6As shown, the present invention proposes a DFB laser control and drive system, including a drive circuit, an RF selector output unit, an optical filter module, a main control module, a current filter module, a monitoring module, and a DFB laser array;

[0027] The drive circuit is connected to the DFB laser array and the RF selector output unit. The DFB laser array is connected to the monitoring module. The monitoring module is connected to the RF selector output unit. The RF selector output unit is connected to the optical filter module and the main control module. The main control module is connected to the current filter module.

[0028] The main control drive circuit mixes and adds the input low-frequency sawtooth wave signal with a high-frequency sine wave signal output from the RF selector output unit to modulate the wavelength of the DFB laser, thereby generating the drive current required for the 1350-1850nm band DFB laser and driving multiple lasers to output optical signals. The RF selector outputs two high-frequency sine wave signals: one as the modulation signal for the drive circuit and the other as the synchronization signal for the main control module. Simultaneously, the RF selector outputs channel selection for the input laser. The optical filtering module, controlled by a microcontroller, uses a combination of hardware and software to filter out input interference bands and other noise by adjusting and switching laser scanning, outputting only a single band of mixed laser signal at any given time. The main control module uses the high-frequency sine wave synchronization signal to synchronize the laser signal, obtaining a complete signal within one cycle. The current filtering module performs high-frequency filtering on the signal processed by the main control module, removing low-frequency signal components from the input signal before output. The monitoring module monitors the temperature and current information of the DFB laser array in real time.

[0029] The RF selector output unit includes a high-frequency sine wave generator circuit and an analog multiplexer. The high-frequency sine wave generator circuit produces high-frequency sine waves with frequencies up to several GHz, which are output to the drive circuit and the main control module. The multiple input laser signals pass through the analog multiplexer module. Each of the multiple DFB laser signals is connected to multiple input ports and shares a single output port. According to specific requirements, the corresponding input and output ports can be opened at the control terminal, and the appropriate input channel can be selected, thereby realizing the analog switching and channel selection functions of multiple laser signals.

[0030] The RF selector outputs a high-frequency sine wave signal and a low-frequency sawtooth wave signal, respectively, which are then fed into the drive circuit to perform signal mixing and addition, thereby generating the drive current required by DFB lasers of different bands. This drives multiple DFB lasers to output laser light. At the same time, the monitoring module monitors the temperature and current information of each DFB laser. The laser light output from the DFB laser passes through the RF selector output to select the channel of the multiple input laser signals. The optical filtering module filters out interference wavelengths and optical noise from the laser light output from the RF selector output, outputting only a single band of mixed laser signal at any given time. The processed optical signal is then output to the main control module. Simultaneously, the RF selector outputs a high-frequency sine wave signal as a synchronization signal, which is fed into the main control module. The main control module uses the high-frequency sine wave signal to synchronize the laser signals, obtaining a complete signal within one cycle. Finally, the optical filtering module filters out low-frequency signals from the signal, and the filtered high-frequency signal is output as the final output signal.

[0031] like Figure 2 As shown, the driving circuit includes a low-pass filter, a mixer, and a voltage-controlled constant current power supply. The mixer is a non-inverting input summing operation circuit composed of integrated amplifiers. The high-frequency sine wave and sawtooth wave input from the outside are filtered by the low-pass filter to remove high-frequency noise, and then enter the mixer for mixing. The mixed electrical signal is connected to the voltage-controlled constant current power supply to perform wavelength modulation on the DFB laser, generating the driving current required by the DFB laser in the 1350-1850nm band. The high-frequency sine wave and low-frequency sawtooth wave output from the RF selection output unit are filtered by the low-pass filter, and the filtered signal is mixed by the mixer. The mixed signal is used as the input of the voltage-controlled constant current source to control the voltage-controlled constant current source to output a stable DFB laser driving circuit.

[0032] like Figure 3 As shown, the sine wave signal and the sawtooth wave signal are first filtered by low-pass filters to remove high-frequency noise. The processed signals are then input to the mixer. The mixer circuit consists of a non-inverting input summing circuit composed of integrated amplifiers to achieve the mixing and addition of the two signals.

[0033] like Figure 4 As shown, the mixed signal serves as the control signal, acting as the output of the voltage-controlled constant current source circuit to drive the current in the drive circuits of DFB lasers of different wavelengths. The voltage-controlled constant current source includes an operational amplifier and a field-effect transistor (FET). The voltage-controlled constant current source circuit utilizes the deep negative feedback of the operational amplifier and the switching characteristics of the FET to precisely control the current flowing through the laser, i.e., to precisely control the current flowing through multiple wavelength DFB lasers. Figure 4 The operational amplifier and capacitor are connected in parallel to form an integrating circuit to prevent circuit oscillation. The reverse diode acts as a shunt to prevent surges in the laser and protect the laser.

[0034] like Figure 5 As shown, the driving circuit drives multiple lasers to output lasers with different center wavelengths. The mixed optical signals enter the RF selector output unit. The RF selector output unit selectively opens one or more laser optical signal output channels for different bands and outputs the optical signals to the optical filtering module.

[0035] The optical filtering module combines hardware and software, utilizing laser scanning control and switching. The software controls the hardware circuitry to continuously scan the input optical signal, acquiring information across all wavelength bands. Then, it automatically performs single-segment scanning, filtering out interference wavelengths and noise caused by changes in the drive circuit and temperature. This filters out interfering wavelengths and other noise, outputting only a single-band mixed laser signal at any given time. The optical filtering module receives the laser signal from the RF selector and, using software-controlled microcontrollers, automatically selects the wavelength to remove interference wavelengths and noise, ensuring signal accuracy.

[0036] After optical filtering, the optical signal enters the main control module. The main control module processes the signal and uses a high-frequency sine wave signal to synchronize the laser signal, obtaining a complete signal within one cycle, which is then output to the current filtering module.

[0037] The electrical filtering module includes a high-pass filter. For the signal processed by the main control module, the electrical filtering module removes low-frequency sawtooth wave signals from the signal to obtain a complete high-frequency signal. The current filtering module receives the signal sent by the main control module and uses the high-pass filter and corresponding circuit to filter the signal, remove low-frequency signals, and output a signal that meets the conditions, which can be used for subsequent spectral measurements.

[0038] The monitoring module includes two high-precision analog-to-digital converters (ADCs). One ADC is connected to the TEC temperature control chip, which transmits temperature information read from the DFB thermistor to the ADC. The ADC converts the temperature signal into a digital signal, which is then processed and stored by the main control module. The other ADC is connected to... Figure 4 At the source of the common-source negative feedback amplifier circuit shown, the analog-to-digital converter converts the DFB drive current into a digital signal, which is then processed and stored by the microcontroller. The processed signal is then displayed on the OLED screen.

[0039] like Figure 6As shown, in order to verify that the present invention has a good driving effect on DFB lasers in the specified band, the present invention simultaneously drives DFB lasers with center wavelengths of 1450nm, 1512nm, 1578nm, and 1653nm. Tunable semiconductor laser absorption spectroscopy is used to detect the gas to be tested. When the laser passes through the gas to be tested at a certain concentration, a certain absorption phenomenon can be clearly observed at the detector port near the center wavelength corresponding to the gas laser.

[0040] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0041] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0042] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0043] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0044] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0045] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A DFB laser control driving system, characterized by, The driving circuit is connected with the DFB laser group and the radio frequency selection output device, the DFB laser group is connected with the monitoring module, the monitoring module is connected with the radio frequency selection output device, the radio frequency selection output device is connected with the optical filter module and the main control module, and the main control module is connected with the current filter module. The driving circuit mixes and adds the input low-frequency sawtooth wave signal and a high-frequency sinusoidal wave signal output by the radio frequency selection output device, wavelength modulates the DFB laser, generates a driving current required by the DFB laser, drives the DFB laser to output an optical signal, and outputs two high-frequency sinusoidal wave signals from the radio frequency selection output device, one of which is used as a modulation signal of the driving circuit, and the other is used as a synchronization signal of the main control module.

2. The DFB laser control driving system according to claim 1, wherein, The monitoring module monitors the temperature and current information of the DFB laser group in real time.

3. The DFB laser control driving system according to claim 1, wherein, The driving circuit includes a low-pass filter, a mixer and a voltage-controlled constant current power supply.

4. The DFB laser control driving system according to claim 3, wherein, The mixer is a same-direction input summation operation circuit composed of an integrated amplifier.

5. The DFB laser control driving system according to claim 3, wherein, The voltage-controlled constant current power supply includes an operational amplifier and a field effect transistor.

6. The DFB laser control driving system according to claim 1, wherein, The radio frequency selection output device includes a high-frequency sinusoidal wave generation circuit and an analog multiplexer.

7. The DFB laser control driving system according to claim 1, wherein, The optical filter module controls the hardware circuit to continuously scan the input optical signal at the software end, obtains all the wave band information of the input signal, and then automatically performs single-section scanning to filter out the interference wave band and other noises.

8. The DFB laser control driving system according to claim 1, wherein, The main control module uses the high-frequency sinusoidal wave synchronization signal to accurately synchronize the laser signal and obtain a complete signal in a period.

9. The DFB laser control driving system according to claim 1, wherein, The current filter module includes a high-pass filter and removes the low-frequency sawtooth wave signal in the signal processed by the main control module to obtain a complete high-frequency signal.

10. The DFB laser control driving system according to claim 1, wherein, The monitoring module comprises an analog-digital converter and an OLED screen, the analog-digital converter converts analog signals of the laser into digital signals and delivers the digital signals to a single-chip microcomputer for data processing, and the single-chip microcomputer delivers the processed data to the OLED screen for display.

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