WO2022016817A1

WO2022016817A1 - Pump source drive control device and method, and fiber laser

Info

Publication number: WO2022016817A1
Application number: PCT/CN2020/141150
Authority: WO
Inventors: 王琳化; 杨德权; 蒋峰
Original assignee: 苏州创鑫激光科技有限公司; 深圳市创鑫激光股份有限公司
Priority date: 2020-06-15
Filing date: 2020-12-30
Publication date: 2022-01-27
Also published as: CN113809624A

Abstract

A pump source drive control device and method, and a fiber laser. The device comprises a controller (21), a pulse-width modulation module (22), a drive circuit (23), and at least one pump source (24) which are electrically connected in sequence. The pulse-width modulation module (22) is used for generating a modulated wave and a carrier according to an analog current signal of a preset value output by the controller (21), modulating the analog current signal of the preset value into a discontinuous waveform signal by means of pulse-width modulation to be used as a drive current signal, and inputting same to the drive circuit (23). Therefore, the advantage of high efficiency of the drive at full load can be sufficiently exerted. At the same time, the pump source (24) always works at the maximum current; therefore, there is no problem of linewidth caused by a continuous current. In addition, the pump source (24) can be enabled to always work in a rated current or no current state, and thus the influence of the current on output light of the pump source (24) is eliminated, the linewidth of the output light is smaller, the design of an optical path of the fiber laser is facilitated, and the wavelength having a high absorption rate is matched better to achieve the high efficiency operation of the fiber laser.

Description

A pump source drive control device, method and fiber laser

technical field

The application belongs to the field of fiber lasers, and in particular relates to a pump source drive control device, method and fiber laser.

Background technique

With the continuous promotion and application of fiber lasers in the fields of industrial processing, experimental equipment and national defense construction, the requirements for optical output power are getting higher and higher, and the electrical power consumption is also getting higher and higher. Improving the efficiency of fiber lasers can effectively improve the energy efficiency ratio. It is of great significance to improve economic efficiency. At present, the pump source of fiber laser mainly adopts linear drive circuit or switch-type drive circuit. Linear drive circuit has advantages in signal response speed and cost, and has high full-load efficiency. It is usually used as a high-power laser drive solution. Switch-type drive circuit It has advantages in adaptability and high overall efficiency, and is usually used in low-power products. Both drives can achieve constant current output of the pump source.

Referring to FIG. 1 , the prior art fiber laser pump source drive control device includes a controller 11 , a drive circuit 12 and a pump source 13 that are electrically connected in sequence, and the drive circuit may be a linear drive circuit or a switch-type drive circuit. That is, in the prior art fiber laser pump source drive control device, the pump source is directly driven by a linear drive circuit or a switch-type drive circuit. Directly using the switching drive circuit to drive the pump source has low full-load efficiency, and due to the continuous change of the pump source current, the current change will cause the output light width of the pump source to become larger, that is, the frequency band of the pump source light is wider, which affects the use of the laser. ; Directly use the linear drive circuit to drive the pump source, the full load efficiency is high, but due to the characteristics of the linear drive itself, the light load efficiency is low, and there is also the problem of wide output light caused by continuous current changes.

Application content

The purpose of this application is to provide a pump source drive control device, method and fiber laser, aiming to solve the problem of low full-load efficiency when directly using a switch-type drive circuit to drive the pump source, and a wider frequency band of the pump source light; To drive the pump source, the full load efficiency is high, the light load efficiency is low, and the frequency band of the pump source light is wider.

In a first aspect, the present application provides a pump source drive control device, which includes a controller, a pulse width modulation module, a drive circuit and at least one pump source that are electrically connected in sequence, and the pulse width modulation module is used to output a preset according to the controller. A modulated wave and a carrier wave are generated from the analog current signal of the predetermined value, and the analog current signal of the preset value is modulated into a discontinuous waveform signal by pulse width modulation, which is input to the driving circuit as a driving current signal, so that the driving circuit controls the pump source.

Further, when the pump source drive control device includes multiple pump sources, the effective value or average output power value of the multiple path discontinuous waveform signals modulated by the pulse width modulation module is the same as the preset value, as the drive of each pump source. The multi-channel discontinuous waveform signals of the current signal have a phase difference.

In a second aspect, the present application provides a fiber laser, including the pump source drive control device.

In a third aspect, the present application provides a pump source drive control method, the method comprising:

The pulse width modulation module generates a modulating wave and a carrier wave according to the analog current signal of the preset value output by the controller, and modulates the analog current signal of the preset value into a discontinuous waveform signal through the pulse width modulation, which is input to the driving circuit as the driving current signal , to control the pump source by the drive circuit.

In the present application, since the pump source drive control device includes a pulse width modulation module that is electrically connected to the drive circuit, a modulated wave and a carrier wave are generated according to the analog current signal of the preset value output by the controller, and the preset value is modulated by pulse width modulation. The value of the analog current signal is modulated into a discontinuous waveform signal as the driving current signal and input to the driving circuit, so that the amplitude of the driving current signal is 0 or the maximum value, and the current output by the pump source is correspondingly 0 or the maximum value. Therefore, the advantage of high drive efficiency at full load can be fully utilized. At the same time, since the pump source always works at the maximum current, there is no line width problem caused by continuous current; The continuous waveform signal has a phase difference, so it can effectively reduce the output pulsation of the optical power and expand the application field of the laser; in addition, the pump source can always work at the rated current or no current state, thereby eliminating the current on the wavelength of the output light of the pump source. For fiber lasers, it is beneficial to the design of the optical path and better match the wavelength of high absorption rate, so as to realize the high-efficiency operation of fiber lasers.

Description of drawings

FIG. 1 is a structural block diagram of a pump source drive control device in the prior art.

FIG. 2 is a structural block diagram of a pump source drive control device provided by an embodiment of the present application.

FIG. 3 is a schematic diagram of waveforms of driving current signals for generating four pump sources.

Figure 4 is a schematic diagram of the 0-25% power drive duty cycle and output waveform.

Figure 5 is a schematic diagram of a 25% power drive duty cycle and an output waveform.

Figure 6 is a schematic diagram of a 25%-50% power drive duty cycle and an output waveform.

FIG. 7 is a schematic diagram of a 50% power drive duty cycle and an output waveform.

FIG. 8 is a schematic diagram of a 50%-75% power drive duty cycle and an output waveform.

FIG. 9 is a schematic diagram of a 75% power drive duty cycle and an output waveform.

Figure 10 is a schematic diagram of the 75%-100% power drive duty cycle and output waveform.

Figure 11 is a schematic diagram of the 100% power drive duty cycle and output waveform.

Figure 12 is a comparison diagram of wavelength variation in modulation and normal continuous mode using the PWM module.

detailed description

In order to make the objectives, technical solutions and beneficial effects of the present application clearer, 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.

In order to illustrate the technical solutions described in the present application, the following specific embodiments are used for description.

Referring to FIG. 2, the pump source drive control device provided by the embodiment of the present application includes a controller 21, a PWM (Pulse Width Modulation, pulse width modulation) module 22, a drive circuit 23 and at least one pump source 24, which are electrically connected in sequence, and the PWM module 22 is used to generate a modulated wave and a carrier wave according to the analog current signal of the preset value output by the controller 21, and through pulse width modulation, the analog current signal of the preset value is modulated into a discontinuous waveform signal as a drive current signal and input to the drive circuit 23. The pump source 24 is controlled by the drive circuit 23 so that the amplitude of the drive current signal is 0 or the maximum value, so that the current output by the pump source is correspondingly 0 or the maximum value. The driving circuit may be a linear driving circuit or a switching type driving circuit.

The discontinuous waveform signal may be a square wave signal, a trapezoidal wave signal, a triangular wave signal or a sawtooth wave signal.

The PWM module 22 can be implemented by an analog circuit or by a digital circuit. Its characteristic is that the PWM module 22 outputs only two states of zero or high level, and the output power is determined by the ratio of the high level.

Since the output power of the pulse signal modulated by the PWM module 22 has a relatively large fluctuation in the driving occasion of a single-channel pump source, the embodiment of the present application is especially suitable for the driving occasion of a multi-channel pump source. The phase shift is added between the signals, thereby reducing the pulsation of the output power, so that the laser can meet more practical application scenarios. When the pump source drive control device provided by the embodiment of the present application is applied to the driving occasion of multiple pump sources, that is, when the pump source drive control device includes multiple pump sources, the effective value or average output of the discontinuous waveform signal modulated by the PWM module 22 The power value is the same as the preset value, and there is a phase difference between the multi-channel discontinuous waveform signals used as the driving current signals of the various pump sources. If the drive circuit is a linear drive circuit, the advantages of high full-load efficiency of the linear drive can be fully utilized, and the amplitude control of the drive current signal can be realized through pulse width modulation.

If it is applied to the driving occasion of N-channel pump sources, the phase difference between the driving current signals of each pump source is 2π/N; The operating time of each pump source in the N-channel pump source in operation is the same or similar, which can effectively improve the service life of the pump source; Allocating the working time of each pump source can not only average the working time of each pump source, but also intelligently reduce the working time of potential high-risk pump sources to maximize the working life/reliability of the system; among them, N≥M ≥1, M and N are both natural numbers.

Please refer to Figure 3, the following is an example of the driving of the 4-channel pump source, where C1, C2, C3, and C4 represent the driving current signals of the 4-channel pump source respectively, Cp is the modulation wave of the PWM module, M1, M2, M3 and M4 It is the carrier corresponding to C1, C2, C3, and C4. The phases of the carriers are shifted by π/2 in turn. The modulating wave Cp is compared with the carrier M1. The modulating wave Cp is higher than the carrier M1. If it is flat, the output waveform C1 is obtained, and in this way, C2, C3 and C4 can be obtained in sequence. The output light waveform of the pump source has the same trend as C1, C2, C3, and C4. After the multi-channel pump source is combined by the beam combiner inside the fiber laser, the waveform is as shown in Co, which realizes the expected waveform.

Please refer to Figure 4 to Figure 11. The following takes the driving of 4-channel pump sources as an example, in which C1, C2, C3, and C4 represent the driving current signals of the 4-channel pump sources respectively, and the driving current signals of each pump source are out of phase by π/ 2. The duty cycle of the driving current signal of each pump source is adjusted in real time according to the preset current to achieve constant current output.

The embodiment of the present application further provides a fiber laser including the pump source driving control device provided by the embodiment of the present application.

The embodiment of the present application also provides a pump source drive control method, the method comprising:

The discontinuous waveform signal is a square wave signal, a trapezoidal wave signal, a triangular wave signal or a sawtooth wave signal.

When the pump source driving control method is applied to multiple pump sources, the effective value or average output power value of the multiple discontinuous waveform signals modulated by the pulse width modulation module is the same as the preset value, which is used as the driving current of each pump source. There is a phase difference between the multiple discontinuous waveform signals of the signal.

When the pump source driving control method is applied to the driving occasion of N-channel pump source, the pulse width modulation module shifts the phase of the carrier wave, so that the phase difference between the driving current signals of each channel of pump source is 2π/N; The controller actively controls the M-channel pump source in the N-channel pump source to operate in a round-robin manner, so that the running time of each pump source in the N-channel pump source in operation is the same or similar, which can effectively improve the service life of the pump source ; Or, set up a working time counter for each pump source, and assign the working time of each pump source by the controller, which can not only average the working time of each pump source, but also intelligently reduce the working time of potentially high-risk pump sources. To maximize the working life/reliability of the system; where N≥M≥1, M and N are both natural numbers.

The duty ratio of the driving current signal of each pump source is adjusted in real time according to the analog current signal of the preset value, so as to realize constant current output.

In the present application, since the pump source drive control device includes a pulse width modulation module that is electrically connected to the drive circuit, a modulated wave and a carrier wave are generated according to the analog current signal of the preset value output by the controller, and the preset value is modulated by pulse width modulation. The value of the analog current signal is modulated into a discontinuous waveform signal as the driving current signal and input to the driving circuit, so that the amplitude of the driving current signal is 0 or the maximum value, and the current output by the pump source is correspondingly 0 or the maximum value. Therefore, it can give full play to the advantages of high efficiency at full load. At the same time, because the pump source always works at the maximum current, there is no line width problem caused by continuous current. In contrast, as shown in Figure 12, compared with the ordinary continuous mode, the PWM module is used for modulation, and the output wavelength variation range is small; Reduce the output pulsation of the optical power and expand the application field of the laser; in addition, the pump source can always work at the rated current or no current state, thereby eliminating the influence of the current on the wavelength of the output light of the pump source, making the line width smaller, and for Fiber lasers are beneficial to the design of optical paths and better match wavelengths with high absorption rates to achieve high-efficiency operation of fiber lasers.

Those of ordinary skill in the art can understand that all or part of the steps in the various methods of the above embodiments can be completed by instructing relevant hardware through a program, and the program can be stored in a computer-readable storage medium, and the storage medium can include: Read only memory (ROM, Read Only Memory), random access memory (RAM, Random Access Memory), magnetic disk or optical disk, etc.

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

A pump source drive control device, characterized in that it includes a controller, a pulse width modulation module, a drive circuit and at least one pump source that are electrically connected in sequence, and the pulse width modulation module is used for an analog current according to a preset value output by the controller The signal generates a modulating wave and a carrier wave, and modulates an analog current signal with a preset value into a discontinuous waveform signal through pulse width modulation, which is input to the driving circuit as a driving current signal, so that the driving circuit controls the pump source.
The pump source drive control device according to claim 1, wherein the discontinuous waveform signal is a square wave signal, a trapezoidal wave signal, a triangular wave signal or a sawtooth wave signal.
The pump source drive control device according to claim 1, wherein when the pump source drive control device includes multiple pump sources, the effective value or average output power of the multiple channels of discontinuous waveform signals modulated by the pulse width modulation module The value is the same as the preset value, and there is a phase difference between the multi-channel discontinuous waveform signals used as the driving current signals of each pump source.
The pump source drive control device according to claim 3, wherein when the pump source drive control device is applied to the driving occasion of N pump sources, the phase difference between the drive current signals of each pump source is 2π /N; where, N≥1, and N is a natural number.
The pump source drive control device according to claim 4, wherein when the pump source drive control device is applied to a driving occasion of four pump sources, the drive current signals of each pump source are out of phase by π/2.
The pump source drive control device according to claim 3, wherein the pump source drive control device actively controls the M pump sources in the N pump sources to operate in a round-robin manner through the controller, so that the running The running time of each pump source in the N pump sources is the same or similar; among them, N≥M≥1, and M and N are both natural numbers.
The pump drive control device according to claim 3, wherein the pump source drive control device respectively sets up a working time counter for each pump source, and the controller allocates the working time of each pump source.
The pump source drive control device according to claim 1, wherein the pulse width modulation module is realized by an analog circuit or a digital circuit.
The pump source drive control device according to claim 8, wherein the pulse width modulation module outputs only two states of 0 or high level, and the level of the output power is determined by the ratio of the high level.
The pump source drive control device according to claim 1, wherein the drive circuit is a linear drive circuit or a switch-type drive circuit.
The pump source drive control device according to claim 1, wherein the amplitude of the drive current signal is 0 or a maximum value, so that the current output by the pump source is 0 or a maximum value.
A fiber laser, characterized by comprising the pump source drive control device according to any one of claims 1 to 11.
A pump source drive control method, characterized in that the method comprises:

The pulse width modulation module generates a modulating wave and a carrier wave according to the analog current signal of the preset value output by the controller, and modulates the analog current signal of the preset value into a discontinuous waveform signal through the pulse width modulation, which is input to the driving circuit as the driving current signal , to control the pump source by the drive circuit.
The pump source drive control method according to claim 13, wherein when the pump source drive control method is applied to multiple pump sources, the effective value or average value of the multiple discontinuous waveform signals modulated by the pulse width modulation module The output power value is the same as the preset value, and there is a phase difference between the multi-channel discontinuous waveform signals used as the driving current signals of the various pump sources.
The pump source drive control method according to claim 14, wherein when the pump source drive control method is applied to the driving occasion of N pump sources, the pulse width modulation module shifts the phase of the carrier wave, so that each pump source The phase difference between the driving current signals is 2π/N; among them, N≥1, and N is a natural number.
The pump source drive control method according to claim 14, wherein the pump source drive control method uses the controller to actively control the M pump sources in the N pump sources to operate in a round-robin manner, so that the running The running time of each pump source in the N pump sources is the same or similar; among them, N≥M≥1, and M and N are both natural numbers.
The pump source drive control method according to claim 14, wherein the pump source drive control method respectively sets up a working time counter for each pump source, and the controller allocates the working time of each pump source.
15. The pump source driving control method according to claim 14, wherein the duty ratio of the driving current signal of each pump source is adjusted in real time according to the preset analog current signal to realize constant current output.
The pump source driving control method according to claim 13, wherein the output of the pulse width modulation module is only 0 or high level, and the level of the output power is determined by the ratio of the high level.
A non-volatile computer-readable storage medium, characterized in that the non-transitory computer-readable storage medium stores program instructions, and when the pump source drive control device executes the program instructions, any one of claims 13 to 19 is executed. The one described pump source drive control method.