CN110854654A - Semi-closed loop control laser - Google Patents

Abstract

The embodiment of the invention provides a semi-closed loop control laser, which comprises: if the beam combining module receives the calibration signal, the beam combining module is used for calculating a target calibration voltage according to a preset calibration power point and sending the target calibration voltage corresponding to the preset calibration power point to the slave control module; the driver is used for generating a target calibration current according to the target calibration voltage, and the pumping source is used for emitting sub laser according to the target calibration current; the beam combining module is used for combining the sub lasers to obtain a total beam; the photodiode is used for detecting the light intensity at the bare fiber and generating actual detection voltage; and the beam combining module is also used for comparing the standard detection voltage with the actual detection voltage and adjusting the target calibration voltage until the optimal calibration voltage is obtained. According to the embodiment of the invention, the laser is calibrated in a semi-closed loop mode, and an anti-reflection optical device is not used, so that the cost of the laser is reduced, and the pressure of a user is reduced.

Description

Semi-closed loop control laser

Technical Field

The invention relates to the technical field of lasers, in particular to a semi-closed loop control laser.

Background

An open-loop control scheme is generally adopted in a traditional laser, generally, a laser power value required by a user is received by a controller such as an MCU (microprogrammed control Unit), a DSP (digital signal processor) or an FPGA (field programmable gate array), and a voltage value corresponding to the laser power value is output from the controller or an external digital-to-analog converter, so that the ACDC power supply is driven by the voltage or the current converted from the voltage to emit corresponding current, a pumping source is driven, and laser with power required by the user is obtained.

However, in such conventional applications, if the user makes the laser head perpendicular to the light-receiving object during use, the light-receiving object may be reflective. Therefore, by adding the optical device for reflection prevention, the optical power received by the photodiode can be enabled to be not much different from the requirement of a user, and the closed loop can be normally closed. However, the cost of the optical device is expensive, which leads to a significant increase in the cost of the laser.

Therefore, a need exists for a low cost laser.

Disclosure of Invention

In order to solve the above problems, embodiments of the present invention provide a semi-closed loop control laser.

The embodiment of the invention provides a semi-closed loop control laser, which comprises: the system comprises a plurality of slave control modules, a beam combining module and a photodiode, wherein any slave control module comprises a plurality of drivers and a plurality of pump sources, each driver is connected with each pump source, and each pump source is connected with the beam combining module through an optical fiber;

if the beam combining module receives the calibration signal, the beam combining module is used for calculating a plurality of target calibration voltages according to a plurality of preset calibration power points, and for any preset calibration power point, the target calibration voltage corresponding to any preset calibration power point is sent to each slave control module;

each driver in any slave control module is used for generating a target calibration current according to the target calibration voltage, and each pumping source is used for emitting sub-lasers with corresponding power according to the target calibration current;

the beam combining module is used for combining the sub-lasers emitted by each pumping source in each slave control module to obtain a total beam, and the total beam is emitted from the beam combining module after passing through a bare fiber;

the photodiode covers the bare fiber, two ends of the photodiode are connected with the beam combining module, and the photodiode is used for detecting the light intensity of the bare fiber and generating actual detection voltage;

the beam combination module is further configured to compare the standard detection voltage corresponding to any one of the preset calibration power points with the actual detection voltage, and adjust the magnitude of the target calibration voltage until an optimal calibration voltage is obtained if an error between the standard detection voltage and the actual detection voltage is outside a preset range, where a difference between the actual detection voltage corresponding to the optimal calibration voltage and the standard detection voltage corresponding to any one of the preset calibration power points is within the preset range.

Preferably, the standard detection voltage corresponding to any one preset calibration power point is obtained by the following method:

before the semi-closed loop control laser leaves a factory, the beam combining module measures a target standard voltage corresponding to any preset calibration power point according to any preset calibration power point;

each driver in any slave control module is used for generating a target standard current according to the target standard voltage, and each pumping source is used for emitting sub-lasers with corresponding power according to the target standard current;

the beam combining module is used for combining the sub-lasers emitted by each pumping source in each slave control module to obtain a total beam;

the photodiode is used for detecting the light intensity of the total light beam at the bare fiber and generating a standard detection voltage corresponding to any one preset calibration power point.

Preferably, the optical system further comprises a beam output head connected with the beam combining module, wherein:

if the beam combining module does not receive the calibration signal, the beam combining module is used for calculating a target output voltage according to a target output power;

each driver in any slave control module is used for generating a target output current according to the target output voltage, and each pumping source is used for emitting sub-lasers with corresponding power according to the target output current;

the beam combining module is used for combining the sub-lasers emitted by each pumping source in each slave control module to obtain a total beam;

the total light beam is emitted from the beam combining module after passing through the bare fiber;

and the total light beam output from the beam combining module passes through the light beam output head and is output.

Preferably, the optical system further comprises a beam output head connected with the beam combining module, wherein:

if the beam combining module does not receive the calibration signal, the beam combining module is used for calculating a target output voltage according to a target output power;

each driver in any slave control module is used for generating a target output current according to the target output voltage, and each pumping source is used for emitting sub-lasers with corresponding power according to the target output current;

the beam combining module is used for combining the sub-lasers emitted by each pumping source in each slave control module to obtain a total beam;

the total light beam is emitted from the beam combining module after passing through the bare fiber;

and the total light beam output from the beam combining module passes through the light beam output head and is output.

Preferably, the beam combining module is configured to calculate a target output voltage according to the target output power, and specifically includes:

the beam combination module is further used for acquiring a calibration relation according to the optimal calibration voltage corresponding to each preset calibration power point and the target calibration voltage corresponding to each preset calibration power point;

and calculating the target output voltage according to the target output power and the calibration relation.

Preferably, each preset calibration power point at least comprises the maximum power and the minimum power of the semi-closed loop control laser.

According to the semi-closed loop control laser provided by the embodiment of the invention, the laser is calibrated in a semi-closed loop mode, and an anti-reflection optical device is not used, so that the cost of the laser is reduced, and the pressure of a user is reduced; and the voltage is compensated, so that compared with the mode of compensating light, the cost is further reduced.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and those skilled in the art can also obtain other drawings according to the drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a semi-closed loop control laser according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of detecting the total light beam by a photodiode according to an embodiment of the present invention;

fig. 3 is a schematic view illustrating the mounting of a photodiode according to an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The conventional laser generally does not adopt a closed-loop control scheme, because the power at the photodiode is equal to the actual light output power plus the reflected power after the light reflection causes the closed-loop failure, which causes the closed-loop failure, the conventional laser generally adopts open-loop control.

Light reflectance is higher than the value detected at the photodiode without reflectance, and user use does not determine whether there is reflectance or no reflectance, so closed loop is not possible. If a closed loop is required, an antireflection optical device must be added, and the cost of the laser increases after the reflection optical device is added.

The embodiment of the invention also adopts open loop, but the light attenuation can be compensated by secondary calibration.

Fig. 1 is a schematic structural diagram of a semi-closed loop control laser according to an embodiment of the present invention, as shown in fig. 1, a thick black line represents an optical fiber, and a thin line represents a conducting wire. The laser includes: the system comprises a plurality ofslave control modules 101, a beam combiningmodule 102 and a photodiode, wherein any slave control module comprises a plurality of drivers and a plurality of pump sources, each driver is connected with each pump source, and each pump source is connected with the beam combining module through an optical fiber;

if the beam combining module receives the calibration signal, the beam combining module is used for calculating a plurality of target calibration voltages according to a plurality of preset calibration power points, and for any preset calibration power point, the target calibration voltage corresponding to any preset calibration power point is sent to each slave control module;

each driver in any slave control module is used for generating a target calibration current according to the target calibration voltage, and each pumping source is used for emitting sub-lasers with corresponding power according to the target calibration current;

the beam combining module is used for combining the sub-lasers emitted by each pumping source in each slave control module to obtain a total beam, and the total beam is emitted from the beam combining module after passing through a bare fiber;

the photodiode covers the bare fiber, two ends of the photodiode are connected with the beam combining module, and the photodiode is used for detecting the light intensity of the bare fiber and generating actual detection voltage;

the beam combination module is further configured to compare the standard detection voltage corresponding to any one of the preset calibration power points with the actual detection voltage, and adjust the magnitude of the target calibration voltage until an optimal calibration voltage is obtained if an error between the standard detection voltage and the actual detection voltage is outside a preset range, where a difference between the actual detection voltage corresponding to the optimal calibration voltage and the standard detection voltage corresponding to any one of the preset calibration power points is within the preset range.

It should be noted that, in the embodiment of the present invention, the standard detection voltage refers to setting the laser to a preset calibration power point when the laser is not attenuated, and detecting the voltage of the total light beam at this time, and taking the voltage as the standard detection voltage.

After a period of use of a conventional laser, because of the attenuation problem that is difficult to avoid by the optical device, the actual optical power of the laser is lower than the user-set power, and therefore, the output power of the laser needs to be calibrated.

The semi-closed loop control laser provided by the invention comprises a plurality of slave control modules and a beam combining module, wherein each slave control module has the same structure, one of the slave control modules is taken as an example for explanation, the slave control module comprises a plurality of drivers and a plurality of pump sources, the number of the drivers is equal to that of the pump sources, each driver is connected with each pump source, and each pump source in the slave control module is respectively connected with the beam combining module through an optical fiber.

When the semi-closed loop control laser is used for a period of time, due to the attenuation of the performance of devices inside the laser, the laser power actually output by the laser is reduced, at this time, the laser needs to be calibrated, a calibration signal is sent to a beam combining module in the laser, after the beam combining module receives the calibration signal, the laser output under a plurality of preset calibration power points is calibrated, by taking any one preset calibration power point as an example, when the preset calibration power point needs to be calibrated, the beam combining module generates corresponding target calibration voltage according to the preset calibration power point, and sends the target calibration voltage to each slave control module through a lead.

In the embodiment of the present invention, after receiving the target calibration voltage, the slave control circuit in the slave control module sends the target calibration voltage to each driver in the slave control module, each driver generates a target calibration current according to the target calibration voltage, and the corresponding pump source generates sub-lasers with corresponding magnitudes according to the target calibration current, and sends the sub-lasers to the beam combining module through the optical fiber.

And a beam combiner in the beam combining module receives all the sub-lasers sent from all the pump sources in the control module, and after the sub-lasers are combined, a total light beam is obtained, and the total light beam passes through a section of bare fiber.

Since the performance of the internal module of the laser is reduced after the laser is used for a period of time, if the laser power output by the laser needs to be checked, the photodiode is used to check the total beam in the embodiment of the present invention.

Specifically, fig. 2 is a schematic diagram of detecting a total light beam by a photodiode in an embodiment of the present invention, as shown in fig. 2, a thick line in the diagram represents an optical fiber, a dashed line represents a bare fiber, and fig. 3 is a schematic diagram of mounting the photodiode in the embodiment of the present invention, as can be seen from fig. 2 and fig. 3:

since the light emitted by the laser has strong power and the laser has strong polymerization, if the light is directly irradiated on the photodiode, the photodiode may be damaged, and therefore, in the embodiment of the invention, the total light beam is detected in a bare fiber manner.

When the total light beam is transmitted in a common optical fiber, the total light beam cannot be emitted from the total optical fiber, therefore, a small section of the optical fiber is stripped to obtain a bare fiber, the total light beam can be emitted from the portion of the bare fiber, a mechanical seat frame is arranged above the bare fiber, the middle of the mechanical seat frame is hollow, a photodiode is arranged at the center of the mechanical seat frame, the photodiode converts the light intensity into a voltage value according to the detected light intensity of the total light beam and transmits the voltage value to a beam combining module, and the beam combining module receives the actual detection voltage.

And after receiving the actual detection voltage, the beam combining module compares the actual detection voltage with the standard detection voltage corresponding to the preset calibration power point, and if the difference value between the actual detection voltage and the standard detection voltage is within a preset range, the actual output power of the semi-closed loop control laser and the power set by a user meet the requirements, and the voltage does not need to be adjusted.

If the difference between the actual detection voltage and the standard detection voltage is outside the preset range, it indicates that the actual detection voltage and the standard detection voltage need to be adjusted, the target calibration voltage output by the beam combination module is continuously adjusted, the corresponding actual detection voltage is obtained by adopting the same method as the method, until the adjusted actual detection voltage is equal to the standard detection voltage, the adjusted target calibration voltage is obtained, and the adjusted target calibration voltage is used as the optimal calibration voltage.

And acquiring the optimal calibration voltage corresponding to each preset calibration power point according to the method, and storing the target calibration voltage corresponding to each preset calibration power point.

When the beam combining module does not receive the calibration signal, but is in a laser output state, if the target output laser power acquired by the beam combining module at the moment is equal to a preset calibration power point, the corresponding optimal calibration voltage is directly acquired without recalculation.

On the basis of the foregoing embodiment, preferably, the beam combining module is further configured to obtain a calibration relationship according to the optimal calibration voltage corresponding to each preset calibration power point and the target calibration voltage corresponding to each preset calibration power point;

and calculating the target output voltage according to the target output power and the calibration relation.

It should be further noted that, the beam combining module further obtains a calibration relationship curve according to the optimal calibration voltage corresponding to each preset calibration power point and the target calibration voltage corresponding to each preset calibration power point, in the embodiment of the present invention, the calibration relationship curve may be:

and the target output voltage is k target output power + b, the target output voltage is the voltage output by the beam combining module, and the target output power is the power set by the user. And calculating the target output voltage according to the relation curve.

According to the semi-closed loop control laser provided by the embodiment of the invention, the laser is calibrated in a semi-closed loop mode, and an anti-reflection optical device is not used, so that the cost of the laser is reduced, and the pressure of a user is reduced; and the voltage is compensated, so that the cost is further reduced compared with the scheme of adding the optical anti-reflection device.

On the basis of the foregoing embodiment, preferably, the standard detection voltage corresponding to any one preset calibration power point is obtained specifically by:

before the semi-closed loop control laser leaves a factory, the beam combining module measures a target standard voltage corresponding to any preset calibration power point according to any preset calibration power point;

each driver in any slave control module is used for generating a target standard current according to the target standard voltage, and each pumping source is used for emitting sub-lasers with corresponding power according to the target standard current;

the beam combining module is used for combining the sub-lasers emitted by each pumping source in each slave control module to obtain a total beam;

the photodiode is used for detecting the light intensity of the total light beam at the bare fiber and generating a standard detection voltage corresponding to any one preset calibration power point.

Specifically, in order to detect the standard detection voltage of the laser when there is no attenuation, the standard detection voltage is generally measured before the laser is shipped, and since all components before the laser is shipped are completely new and there is no attenuation, in the embodiment of the present invention, the standard detection voltage is measured under such a condition, and a standard detection voltage corresponding to one preset calibration power point is taken as an example for description:

before the laser leaves the factory, a calibration signal is not sent to the beam combining module, the power of the beam combining module is set to the preset calibration power point, and the beam combining module calculates the target standard voltage according to the preset calibration power point.

Each driver in all the slave control modules is used for generating a target standard current according to the target standard voltage, each pumping source is used for emitting sub-lasers with corresponding power according to the target standard current, the beam combining module is used for combining the sub-lasers emitted by each pumping source in each slave control module to obtain a total light beam, the photodiode detects the light intensity of the total light beam at the bare fiber, a corresponding voltage is generated according to the light intensity, and the voltage is used as a standard detection voltage corresponding to the preset calibration power point.

On the basis of the above embodiment, preferably, the optical system further includes a beam output head, the beam output head is connected to the beam combining module, wherein:

if the beam combining module does not receive the calibration signal, the beam combining module is used for calculating a target output voltage according to a target output power;

each driver in any slave control module is used for generating a target output current according to the target output voltage, and each pumping source is used for emitting sub-lasers with corresponding power according to the target output current;

the beam combining module is used for combining the sub-lasers emitted by each pumping source in each slave control module to obtain a total beam;

the total light beam is emitted from the beam combining module after passing through the bare fiber;

and the total light beam output from the beam combining module passes through the light beam output head and is output.

Specifically, when the laser is in a normal use state, a calibration signal is not sent to the beam combining module, the beam combining module receives a target output power set by a user, if the laser is not calibrated at this time, a target output voltage is calculated by directly combining internal structure parameters of the laser according to a laser power calculation formula, then a corresponding total light beam is output according to the same method, and the total light beam is output from the beam combining module and then is output from a light beam output head connected with the beam combining module, so that the required laser can be obtained.

On the basis of the foregoing embodiment, preferably, the beam combining module is configured to calculate a target output voltage according to the target output power, and specifically, the target output voltage is calculated by:

the beam combination module is also used for storing each preset calibration power point and the optimal calibration voltage corresponding to each preset calibration power point;

and if the target output power is equal to any preset calibration power point, the beam combining module directly acquires the corresponding optimal calibration voltage from a storage unit, and the optimal calibration voltage is used as the target output voltage.

Specifically, if the laser is calibrated, since the beam combining module in the laser stores the optimal calibration voltage corresponding to each preset calibration power point, when the target output voltage is calculated, if the target output power is equal to any one of the preset calibration power points, the corresponding optimal calibration voltage can be directly selected from the stored data, and the optimal calibration voltage is taken as the target output voltage without recalculation.

On the basis of the above embodiment, preferably, each preset calibration power point includes at least the maximum power and the minimum power of the semi-closed loop control laser.

Specifically, the greater the number of preset calibration power points, the better the accuracy of the final output, but at least two calibration points including the maximum power and the minimum power should be given.

The above-described embodiments of the apparatus are merely illustrative, and the units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the present embodiment. One of ordinary skill in the art can understand and implement it without inventive effort.

Through the above description of the embodiments, those skilled in the art will clearly understand that each embodiment can be implemented by software plus a necessary general hardware platform, and certainly can also be implemented by hardware. With this understanding in mind, the above-described technical solutions may be embodied in the form of a software product, which can be stored in a computer-readable storage medium such as ROM/RAM, magnetic disk, optical disk, etc., and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute the methods described in the embodiments or some parts of the embodiments.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.

Claims (6)

1. A semi-closed loop controlled laser, comprising: the system comprises a plurality of slave control modules, a beam combining module and a photodiode, wherein any slave control module comprises a plurality of drivers and a plurality of pump sources, each driver is connected with each pump source, and each pump source is connected with the beam combining module through an optical fiber;

if the beam combining module receives the calibration signal, the beam combining module is used for calculating a plurality of target calibration voltages according to a plurality of preset calibration power points, and for any preset calibration power point, the target calibration voltage corresponding to any preset calibration power point is sent to each slave control module;

each driver in any slave control module is used for generating a target calibration current according to the target calibration voltage, and each pumping source is used for emitting sub-lasers with corresponding power according to the target calibration current;

the beam combining module is used for combining the sub-lasers emitted by each pumping source in each slave control module to obtain a total beam, and the total beam is emitted from the beam combining module after passing through a bare fiber;

the photodiode covers the bare fiber, two ends of the photodiode are connected with the beam combining module, and the photodiode is used for detecting the light intensity of the bare fiber and generating actual detection voltage;

the beam combination module is further configured to compare the standard detection voltage corresponding to any one of the preset calibration power points with the actual detection voltage, and adjust the magnitude of the target calibration voltage until an optimal calibration voltage is obtained if an error between the standard detection voltage and the actual detection voltage is outside a preset range, where a difference between the actual detection voltage corresponding to the optimal calibration voltage and the standard detection voltage corresponding to any one of the preset calibration power points is within the preset range.

2. The semi-closed loop control laser device according to claim 1, wherein the standard detection voltage corresponding to any one of the preset calibration power points is obtained by:

before the semi-closed loop control laser leaves a factory, the beam combining module measures a target standard voltage corresponding to any preset calibration power point according to any preset calibration power point;

each driver in any slave control module is used for generating a target standard current according to the target standard voltage, and each pumping source is used for emitting sub-lasers with corresponding power according to the target standard current;

the beam combining module is used for combining the sub-lasers emitted by each pumping source in each slave control module to obtain a total beam;

the photodiode is used for detecting the light intensity of the total light beam at the bare fiber and generating a standard detection voltage corresponding to any one preset calibration power point.

3. The semi-closed loop control laser of claim 1, further comprising a beam output head coupled to the beam combining module, wherein:

if the beam combining module does not receive the calibration signal, the beam combining module is used for calculating a target output voltage according to a target output power;

each driver in any slave control module is used for generating a target output current according to the target output voltage, and each pumping source is used for emitting sub-lasers with corresponding power according to the target output current;

the beam combining module is used for combining the sub-lasers emitted by each pumping source in each slave control module to obtain a total beam;

the total light beam is emitted from the beam combining module after passing through the bare fiber;

and the total light beam output from the beam combining module passes through the light beam output head and is output.

4. The semi-closed loop control laser as claimed in claim 3, wherein the beam combining module is configured to calculate a target output voltage according to the target output power, specifically:

the beam combination module is also used for storing each preset calibration power point and the optimal calibration voltage corresponding to each preset calibration power point;

and if the target output power is equal to any preset calibration power point, the beam combining module directly acquires the corresponding optimal calibration voltage from a storage unit, and the optimal calibration voltage is used as the target output voltage.

5. The semi-closed loop control laser as claimed in claim 3, wherein the beam combining module is configured to calculate a target output voltage according to the target output power, specifically:

the beam combination module is further used for acquiring a calibration relation according to the optimal calibration voltage corresponding to each preset calibration power point and the target calibration voltage corresponding to each preset calibration power point;

and calculating the target output voltage according to the target output power and the calibration relation.

6. The semi-closed loop control laser of claim 1, wherein each predetermined calibration power point comprises at least a maximum power point and a minimum power point of the semi-closed loop control laser.

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