CN111600197B

CN111600197B - Light-emitting power monitoring and APC control circuit and method based on EA photocurrent

Info

Publication number: CN111600197B
Application number: CN202010439815.5A
Authority: CN
Inventors: 杨洪
Original assignee: Source Photonics Chengdu Co Ltd
Current assignee: Source Photonics Chengdu Co Ltd
Priority date: 2020-05-22
Filing date: 2020-05-22
Publication date: 2023-03-31
Anticipated expiration: 2040-05-22
Also published as: CN111600197A

Abstract

The invention relates to a light-emitting power monitoring and APC control circuit and a method based on EA photocurrent, which are used for monitoring the light-emitting power of a laser and comprise a sampling acquisition circuit, a monitoring module and a PID controller, wherein the sampling acquisition circuit acquires the light-emitting power of the laser and sends the light-emitting power to the PID controller and the monitoring module, the monitoring module judges whether the current light-emitting power of the laser is under the set light-emitting power or not, a detection result is obtained and then fed back to the PID controller, and the PID controller adjusts the Bias current of the laser according to the detection result, so that the laser works under the required light-emitting power. The sampling and collecting circuit is used for replacing the problem that the cost is high when the existing PD light receiver is used for collecting the luminous power of the laser, when the sampling and collecting circuit sends the collected luminous power to the PID controller, the monitoring on the luminous power of the laser is realized, and when the PID controller adjusts the Bias current output by the laser according to the detection result, the APC control on the laser is realized.

Description

Light-emitting power monitoring and APC control circuit and method based on EA photocurrent

Technical Field

The invention relates to the technical field of laser power control, in particular to a circuit and a method for monitoring luminous power and controlling APC (automatic Power control) based on EA (emitter) photocurrent.

Background

In the field of photoelectric technology, when a laser works in a locked state, the working power condition of the laser needs to be detected in real time, the traditional detection mode is that a PD light receiver is matched with the laser, the PD light receiver senses laser emitted by the laser, converts the laser into an electric signal and feeds the electric signal back to a controller, and the controller calculates according to the electric signal fed back by the PD light receiver, so that the power of the laser is obtained, and whether the voltage output by the laser needs to be adjusted or not is judged.

In practical use, the number of lasers is large, the price of the PD light receiver is expensive, which is up to $ 5 and one, and even the unit price is higher, so that the cost of the whole device is greatly increased, and the concept of saving resources is not met.

Disclosure of Invention

The invention aims to solve the problem that a PD monitoring device in the prior art is expensive, and provides a luminous power monitoring and APC control circuit and method based on EA photocurrent, which can monitor the luminous power and APC of a laser by adding a cheap sampling acquisition circuit and a monitoring module, thereby saving the cost.

In order to achieve the above object, the embodiments of the present invention provide the following technical solutions:

the utility model provides a luminous power monitoring and APC control circuit based on EA photocurrent, monitors the luminous power of laser instrument, includes sample acquisition circuit, monitoring module, PID controller, wherein:

the sampling acquisition circuit is used for acquiring a photocurrent signal of the laser, converting the acquired photocurrent signal of the laser into a voltage signal and then transmitting the voltage signal to the PID controller and the monitoring module, or directly transmitting the acquired photocurrent signal of the laser to the PID controller;

the monitoring module is used for detecting the voltage signal sent by the sampling acquisition circuit and feeding back a detection result to the PID controller;

and the PID controller is used for receiving the photocurrent signal or the voltage signal sent by the sampling acquisition circuit, monitoring the luminous power of the laser, and adjusting the Bias current of the laser according to the detection result fed back by the monitoring module, so that the luminous power of the laser is stabilized to the set luminous power, and the APC control of the laser is realized.

The scheme is that the sampling acquisition circuit is added, and the monitoring module is connected with the sampling acquisition circuit, the sampling acquisition circuit acquires the luminous power output by the laser, and transmits the luminous power of the laser to the monitoring module and the PID controller, the monitoring module detects the luminous power of the laser, the luminous power is fed back to the PID controller after a detection result is obtained, and the PID controller adjusts the Bias current of the laser according to the detection result, so that the laser works under the required luminous power. The sampling acquisition circuit is used for replacing the problem of high cost caused by the fact that the existing PD light receptor is used for acquiring the light emitting power of the laser, the sampling acquisition circuit realizes monitoring of the light emitting power of the laser when transmitting the acquired photocurrent signal to the PID controller, and the APC control of the laser is realized when the PID controller adjusts the Bias current of the optical module to the laser according to the detection result fed back by the monitoring module.

Furthermore, in order to better realize the invention, the sampling acquisition circuit comprises an EA electric absorption modulator, a sampling resistor Rs1, a resistor R3 and an operational amplifier U1; the EA electric absorption modulator collects an optical signal output by the laser and converts the optical signal into a photocurrent signal; after the photocurrent signal passes through a sampling resistor Rs1, a resistor R1 and a resistor R3 acquire voltages at two ends of the sampling resistor Rs1, the photocurrent signal output by the EA electro-absorption modulator is converted into a voltage signal after being amplified by an operational amplifier U1, and then the voltage signal is respectively sent to a monitoring module and a PID controller; or directly sending the photocurrent signal output by the EA electro-absorption modulator to the PID controller.

In the scheme, an EA electric absorption modulator, a resistor and an operational amplifier used by a sampling and collecting circuit are extremely low-price devices, can directly collect optical signals output by a laser, and then convert the optical signals into light current signals, and further amplify and convert the light current signals into voltage signals; the converted photocurrent signal or the converted voltage signal is sent to a PID controller, so that the light-emitting power of the laser is monitored; meanwhile, each laser does not need to be provided with one PD light receiver, and the problem of extremely high cost caused by the use of the PD light receiver is solved.

Furthermore, in order to better implement the present invention, the monitoring module is a single chip microcomputer with an ADC conversion module, the operational amplifier U1 converts the photocurrent signal output by the EA electro-absorption modulator into a voltage signal after amplification, and sends the voltage signal to the ADC conversion module, and the ADC conversion module converts the voltage signal into a digital signal recognizable by the single chip microcomputer and then sends the digital signal to the single chip microcomputer for detection.

In the scheme, the sampling acquisition circuit converts an optical signal output by the laser into a voltage signal, the voltage signal is converted into a data signal which can be identified by the singlechip through the ADC (analog to digital converter) conversion module and then is sent to the singlechip for detection, and the singlechip can compare the received signal with the set luminous power, judge whether the current luminous power of the laser is equal to the set required luminous power or not, obtain a detection result and send the detection result to the PID controller; and the PID controller adjusts the Bias current of the laser according to the detection result, so that the laser can work under the set required light-emitting power, and the APC control of the laser is realized.

A light emitting power monitoring and APC control method based on EA photocurrent includes the following steps:

the sampling acquisition circuit acquires a photocurrent signal of the laser, sends the photocurrent signal to the monitoring module for detection, and sends the photocurrent signal to the PID controller to realize monitoring of the luminous power of the laser;

the monitoring module feeds back the detection result to the PID controller, and the PID controller adjusts the Bias current of the laser according to the detection result, so that the light-emitting power output by the laser is stabilized to the set light-emitting power, and the APC control of the laser is realized.

Furthermore, in order to better implement the present invention, the sampling and collecting circuit collects the photocurrent signal of the laser, and sends the photocurrent signal to the monitoring module for detection, and sends the photocurrent signal to the PID controller, so as to implement the step of monitoring the luminous power of the laser, including:

the EA electric absorption modulator of the sampling acquisition circuit acquires an optical signal output by the laser and converts the optical signal into a photocurrent signal; the photocurrent signal flows through a sampling resistor Rs1, a resistor R1 and a resistor R3 in the sampling acquisition circuit acquire voltages at two ends of the sampling resistor Rs1, the voltages are sent to an operational amplifier U1 to be amplified, the amplified voltages are converted into voltage signals through the operational amplifier U1, and the voltage signals serve as the light-emitting power of the laser and are sent to a monitoring module to be detected; and meanwhile, the voltage signal is used as the luminous power of the laser to be sent to a PID controller, or the photocurrent signal is directly sent to the PID controller, so that the luminous power of the laser is monitored.

Further, in order to better implement the present invention, the step of sending the voltage signal as the light emitting power of the laser to the monitoring module for detection includes:

an ADC conversion module in the monitoring module converts a voltage signal sent by the operational amplifier U1 into a digital signal which can be identified by the single chip microcomputer and then sends the digital signal to the single chip microcomputer for detection, and the single chip microcomputer judges whether the luminous power of the laser is the set luminous power or not and obtains a detection result.

Furthermore, in order to better implement the present invention, the detection result obtained by the single chip microcomputer includes:

if the luminous power of the laser is equal to the set luminous power, obtaining a detection result without adjusting the current;

if the luminous power of the laser is larger than the set luminous power, obtaining a detection result of reducing the current;

and if the luminous power of the laser is smaller than the set luminous power, obtaining a detection result of the increased current.

Furthermore, in order to better implement the present invention, the monitoring module feeds back the detection result to the PID controller, and the PID controller adjusts the Bias current of the laser according to the detection result, so that the light emitting power output by the laser is stabilized to the set light emitting power, thereby implementing the APC control of the laser, including:

if the PID controller receives a detection result that the current is not adjusted and is sent by the singlechip, the Bias current of the laser is not adjusted;

if the PID controller receives a detection result sent by the singlechip to reduce the current, the PID controller outputs a control signal to reduce the base voltage of the triode T1, so that the Bias current output to the laser is reduced, and the luminous power of the laser can be reduced to the set luminous power;

if the PID controller receives a detection result sent by the singlechip to increase the current, the PID controller outputs a control signal to increase the base voltage of the triode T1, so that the Bias current output to the laser is increased, the luminous power of the laser can be increased to the set luminous power, and the APC control of the laser is realized.

Compared with the prior art, the invention has the following beneficial effects:

this scheme adds the sampling circuit, and the monitoring module who is connected with the sampling circuit, use the sampling circuit to acquire the current work luminous power of laser instrument, and send it to the PID controller and monitor, and send work luminous power to monitoring module, monitoring module detects it, judge whether the current luminous power of laser instrument is under the luminous power of settlement, and then feed back to the PID controller after reacing the testing result, the Bias electric current of laser instrument is adjusted according to the testing result to the PID controller, make laser instrument work under required luminous power. The sampling acquisition circuit is used for replacing the problem that the existing PD light receptor is high in cost when used for acquiring the light emitting power of the laser, the sampling acquisition circuit realizes the monitoring of the light emitting power of the laser when transmitting the acquired photocurrent signal or the converted voltage signal to the PID controller, and the APC control of the laser is realized when the PID controller adjusts the Bias current output by the laser according to the detection result fed back by the monitoring module.

And EA electric absorption modulator, resistance and fortune that use in the sample collection circuit put the ware and all are low price's device, have solved the problem that the original is with high costs that gathers the luminous power of laser instrument through setting up expensive PD photic ware, accord with the theory of resources are saved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and those skilled in the art can also obtain other related drawings based on the drawings without inventive efforts.

FIG. 1 is a schematic diagram of the circuit principle of the sampling acquisition circuit, the PID controller and the laser of the invention.

Detailed Description

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 only a part of the embodiments of the present invention, and not all of the embodiments. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.

Example 1:

the invention is realized by the following technical scheme that the EA photocurrent-based luminous power monitoring and APC control circuit monitors the luminous power of a laser, and comprises a sampling acquisition circuit, a monitoring module and a PID controller, wherein an EA photocurrent signal is output to the laser by an optical module, the sampling acquisition circuit acquires the luminous power of the laser and respectively transmits the luminous power to the monitoring module and the PID controller after acquisition, the monitoring module detects the luminous power of the laser and transmits a detection result to the PID controller, and the PID controller adjusts the Bias current of the laser according to the detection result, so that the laser can work under the luminous power set by the optical module.

According to the scheme, a sampling acquisition circuit, a monitoring module and a PID controller are added to a feedback path, the sampling acquisition circuit acquires an optical signal of the laser, converts the optical signal into an optical current signal, converts the optical current signal into a voltage signal, and sends the converted optical current signal or the converted voltage signal to the PID controller, so that the light-emitting power of the laser can be monitored; and the sampling acquisition circuit sends the converted voltage signal to the monitoring module for detection, judges whether the current luminous power of the laser is the luminous power corresponding to the EA photocurrent signal output by the optical module, and feeds back the detection result to the PID controller after obtaining the detection result, and the PID controller adjusts the Bias current of the laser according to the detection result fed back by the singlechip, so that the laser works at the set luminous power, and the APC control of the laser is realized.

In detail, the sampling and collecting circuit comprises an EA electro-absorption modulator, a sampling resistor Rs1, a resistor R3 and an operational amplifier U1; the EA electric absorption modulator collects an optical signal output by the laser and converts the optical signal into a photocurrent signal; after the photocurrent signal passes through a sampling resistor Rs1, a resistor R1 and a resistor R3 acquire voltages at two ends of the sampling resistor Rs1, the photocurrent signal output by the EA electro-absorption modulator is converted into a voltage signal after being amplified by an operational amplifier U1, and then the voltage signal is respectively sent to a monitoring module and a PID controller; or directly sending the photocurrent signal output by the EA electro-absorption modulator to a PID controller.

EA electric absorption modulator response laser instrument's light signal, convert light signal to the photocurrent signal, this photocurrent signal is behind sampling resistor Rs1, and resistance R1, resistance R3 acquire the voltage at sampling resistor Rs1 both ends, convert voltage signal after enlarging by fortune amplifier U1, send this voltage signal to monitor module and PID controller respectively again.

According to the scheme, the current light signal of the laser is obtained, then the light signal is converted into the photocurrent signal and then is converted into the voltage signal, so that the current luminous power of the laser is obtained, the photocurrent signal or the voltage signal is sent to the PID controller, the PID controller can obtain the luminous power of the laser according to the photocurrent signal or the voltage signal, and therefore the luminous power of the laser is monitored.

It should be noted that, when the PID controller is composed of a hardware circuit, the operational amplifier U1 is required to convert the photocurrent signal into a voltage signal, and then feed back the voltage signal to the PID controller; when the PID controller is built for software, the operational amplifier U1 can directly send an optical current signal to the PID controller.

And the singlechip judges whether the luminous power of the laser is the luminous power corresponding to the EA photocurrent output by the optical module to the laser, if not, the singlechip makes a detection result that the Bias current of the laser needs to be adjusted, and feeds the detection result back to the PID controller.

The PID controller adjusts the Bias current of the laser according to the detection result fed back by the singlechip, so that the laser can work under the required luminous power, and the APC control of the laser is realized. The detection result comprises that the Bias current of the laser is not adjusted, and the Bias current of the laser is increased or decreased.

Based on the circuit, the invention also provides a light-emitting power monitoring and APC control method based on EA photocurrent, which comprises the following steps:

the method comprises the following steps of S1: the sampling acquisition circuit acquires a photocurrent signal of the laser, sends the photocurrent signal to the monitoring module for detection, and sends the photocurrent signal to the PID controller, so that the luminous power of the laser is monitored.

The EA electric absorption modulator of the sampling acquisition circuit acquires an optical signal output by the laser and converts the optical signal into a photocurrent signal; the photocurrent signal flows through sampling resistor Rs1, and resistance R1, resistance R3 among the sampling acquisition circuit acquire the voltage at sampling resistor Rs1 both ends to send and amplify to fortune putting ware U1, convert voltage signal into after fortune putting ware U1 enlargies, this voltage signal sends as the luminous power of laser and detects to monitoring module.

The detection result obtained by the single chip microcomputer comprises: if the luminous power of the laser is equal to the set luminous power, obtaining a detection result of current unadjusted; if the luminous power of the laser is larger than the set luminous power, obtaining a detection result of reducing the current; and if the luminous power of the laser is smaller than the set luminous power, obtaining the detection result of the increased current.

And meanwhile, the voltage signal is used as the luminous power of the laser and sent to a PID controller, or the photocurrent signal is directly sent to the PID controller, so that the luminous power of the laser is monitored.

Step S2: the monitoring module feeds back the detection result to the PID controller, and the PID controller adjusts the Bias current of the laser according to the detection result, so that the light-emitting power output by the laser is stabilized to the set light-emitting power, and the APC control of the laser is realized.

The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present invention, and all the changes or substitutions should be covered within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A light emitting power monitoring and APC control circuit based on EA photocurrent, which monitors the light emitting power of a laser, is characterized in that: including sample acquisition circuit, monitor module, PID controller, wherein:

the sampling acquisition circuit is used for acquiring photocurrent signals of the laser, converting the acquired photocurrent signals of the laser into voltage signals and then transmitting the voltage signals to the PID controller and the monitoring module, or directly transmitting the acquired photocurrent signals of the laser to the PID controller;

the sampling and collecting circuit comprises an EA electro-absorption modulator, a sampling resistor Rs1, a resistor R3 and an operational amplifier U1; the EA electric absorption modulator collects an optical signal output by the laser and converts the optical signal into a photocurrent signal; after the photocurrent signal passes through a sampling resistor Rs1, a resistor R1 and a resistor R3 acquire voltages at two ends of the sampling resistor Rs1, the voltages are amplified by an operational amplifier U1, the photocurrent signal output by the EA electro-absorption modulator is converted into voltage signals, and the voltage signals are respectively sent to a monitoring module and a PID controller; or directly sending the photocurrent signal output by the EA electro-absorption modulator to a PID controller;

2. The EA photocurrent based luminous power monitoring and APC control circuit of claim 1, wherein: the monitoring module is a single chip microcomputer with an ADC (analog to digital converter) conversion module, the operational amplifier U1 converts a photocurrent signal output by the EA electric absorption modulator into a voltage signal after amplification, and sends the voltage signal to the ADC conversion module, and the voltage signal is converted into a digital signal which can be recognized by the single chip microcomputer by the ADC conversion module and then enters the single chip microcomputer for detection.

3. A light emitting power monitoring and APC control method based on EA photocurrent is characterized in that: the method comprises the following steps:

the sampling acquisition circuit acquires a photocurrent signal of the laser, and sends the photocurrent signal to the monitoring module for detection and the PID controller to realize monitoring of the luminous power of the laser;

the sample acquisition circuit gathers the photocurrent signal of laser instrument to send and detect to monitoring module, and send to the PID controller, realize carrying out the step monitored to the luminous power of laser instrument, include:

the EA electric absorption modulator of the sampling acquisition circuit acquires an optical signal output by the laser and converts the optical signal into a photocurrent signal;

the photocurrent signal flows through a sampling resistor Rs1, a resistor R1 and a resistor R3 in the sampling acquisition circuit acquire voltages at two ends of the sampling resistor Rs1, the voltages are sent to an operational amplifier U1 for amplification, the voltages are converted into voltage signals after being amplified by the operational amplifier U1, and the voltage signals serve as the luminous power of a laser and are sent to a monitoring module for detection;

meanwhile, the voltage signal is used as the luminous power of the laser and sent to a PID controller, or the photocurrent signal is directly sent to the PID controller, so that the luminous power of the laser is monitored;

the monitoring module feeds back the detection result to the PID controller, and the PID controller adjusts the Bias current of the laser according to the detection result, so that the luminous power output by the laser is stabilized to the set luminous power, and the APC control of the laser is realized.

4. The method as claimed in claim 3, wherein the method comprises the steps of: the voltage signal is sent to the step that the monitoring module detects as the luminous power of laser instrument, includes:

5. The method as claimed in claim 4, wherein the method comprises the steps of: the detection result obtained by the single chip microcomputer comprises:

6. The method as claimed in claim 5, wherein the method comprises the steps of: the monitoring module feeds back the detection result to the PID controller, the PID controller adjusts the Bias current of the laser according to the detection result, so that the luminous power output by the laser is stabilized to the set luminous power, and the APC control of the laser is realized, and the method comprises the following steps: