CN111969410A - Laser diode driving device capable of being remotely controlled in wide temperature change environment - Google Patents

Abstract

The invention discloses a laser diode driving device capable of being remotely controlled in a wide temperature change environment, which provides stable and reliable laser for the field calibration of a ray detector, and comprises: the aluminum material supporting structure selects a laser diode with photosensitive feedback output as a laser source, samples a photosensitive feedback signal PD to monitor the luminous intensity of the laser diode in real time, the photosensitive feedback signal PD is a current signal flowing through the laser diode, is amplified and converted into a voltage signal through an I/V conversion circuit from current to voltage, is acquired by an ADC (analog to digital converter) to convert an analog voltage signal into a digital signal, is transmitted to an FPGA (field programmable gate array), is calculated through FPGA power compensation, sends a corresponding digital signal, converts the digital signal into the analog voltage signal through the DAC, and drives a constant current source circuit to provide driving current for the laser diode.

Description

A Remotely Controlled Laser Diode Driving Device in Wide Temperature Variation Environment

technical field

The invention relates to the field of ray detector on-site calibration and laser diode drive control, in particular to a drive device that can be used in a wide temperature change environment and can remotely control the luminous intensity of a laser diode in real time.

Background technique

The International Thermonuclear Experimental Reactor (ITER) project uses a soft X-ray camera to collect the soft X-ray radiation signal in its device. The ray camera is mounted on the horizontal window of the vacuum chamber of the ITER unit. Since some functions of the soft X-ray camera in the ITER device need to be self-checked and calibrated, a laser diode (LD) is used as the light source to realize the self-check and calibration function of the electronic system of the soft X-ray camera. Because the working environment temperature range of soft X-ray camera detectors and laser diodes is up to (20℃-45℃), the luminous intensity of ordinary laser diodes and laser diode driving devices is unstable under the conditions of temperature changes, and it is impossible to realize the detection of detectors. Therefore, it is necessary to design a device that can remotely control the luminous intensity of the LD and stabilize its own luminous intensity under ambient temperature changes.

SUMMARY OF THE INVENTION

The purpose of the present invention is to enable the laser diode to be remotely controlled in a wide temperature change environment and to stabilize the luminous intensity of the laser diode.

The invention is realized through the following technical solutions: a laser diode driving device that can be remotely controlled in a wide temperature change environment, providing a stable and reliable laser for on-site calibration of ray detectors, and the wide temperature range refers to: 20°C- 45°C; the drive device includes:

The laser diode with photosensitive feedback output is selected as the laser source, and the photosensitive feedback signal PD is sampled to monitor the luminous intensity of the laser diode in real time. The photosensitive feedback signal PD is the current signal flowing through the laser diode. The conversion circuit amplifies and converts it into a voltage signal. The ADC collects and converts the analog voltage signal into a digital signal and transmits it to the FPGA. Through the FPGA power compensation calculation, the corresponding digital signal is sent, and the digital signal is converted into an analog voltage signal by the DAC to drive the constant current source. The circuit provides the drive current for the laser diode.

Further, it includes a constant current source circuit with control of luminous intensity, a PD signal conditioning module with laser diode photosensitive feedback signal, ADC sampling module, FPGA-based power compensation algorithm module, DAC voltage output module, and RS232 communication with the host computer. Serial port module.

Further, the FPGA is used to control the constant current source to send out a narrow pulse current signal, the narrowest pulse is within 100ns, the narrow pulse laser signal is used for the measurement of the response rate of the detector, and the noise floor and baseline offset of the detector are measured at the same time. ;The FPGA can realize fast self-calibration function, convert analog signal from ADC to digital signal after FGPA processing, and then convert it into analog signal by DAC, the processing time of the whole process is at the μs level, and the transmission time of the rest of the circuit signals is at the ns level .

Further, the drive current, working mode, limiting current, and limiting voltage parameter settings of the laser diode can be remotely configured through the host computer, and the PD current of the photosensitive feedback signal can be monitored and displayed in real time. Damage caused by overcurrent or overvoltage;

There are two operating modes for controlling the laser diode, one is the constant optical power mode, and the other is the constant driving current mode.

Further, use FPGA to realize information exchange with the host computer through 232 communication, change the current supplied to the laser diode LD in real time and the data accuracy is at the thousandth level, and real-time check the operating status of the laser diode LD, including the input current provided to the laser diode LD. , The feedback current of the photosensitive feedback signal PD is collected and displayed in real time, and the data accuracy is at the thousandth level.

Further, the device is connected to the laser diode using the Remo connector, which increases the maintenance efficiency. At the same time, the device is small in size: 104mm × 76mm × 46mm. It can work normally when powered by the mini USB 5V interface, which is convenient for the on-site calibration of the ray detector. Work.

Further, it has an aluminum material support structure. The input and output signals and power interfaces of the electronic board card that control the luminous intensity of the laser diodes are designed on the side of the aluminum shell. Plug in, the power interface is a USB port.

Further, the electronic board card for controlling the luminous intensity of the laser diode communicates with the host computer through the RS232 interface, selects the mode and sets the current size and limit value through the host computer to control the board card, and sees the FPGA transmission through the host computer interface. logical bytes.

Further, under different temperature conditions, the feedback current of the PD pin of the laser diode will change. The drive current is adjusted to compensate the luminous intensity of the laser diode.

The advantages of the present invention are:

The present invention has two ways of driving the laser diode, one is to adjust the current signal by the PD feedback, and the other is that the operator actively controls the driving current on the host computer; the present invention can adjust the luminous power of the laser diode in a wide temperature change environment. In the environment of temperature change, the PD feedback current will change, and the adjustment of the driving current of the laser diode is realized through the change of the feedback current, so as to realize the adjustment of the luminous power. The invention has the function of remotely controlling the luminous power of the laser diode, and the setting parameters and the actual numerical precision are at the thousandth level. The present invention has real-time responsiveness, and the response time is at the μs level. The invention can control the laser diode to emit narrow pulse laser through FPGA, which can be used for the measurement of parameters such as the response rate of the detector, the noise floor and the baseline shift; the invention can prevent the laser diode from Damage caused by overcurrent or overvoltage; the present invention has low power consumption and low cost.

Description of drawings

Fig. 1 is the structure diagram of the present invention;

Fig. 2 is the FPGA internal module structure diagram of the present invention;

Fig. 3 is the data reading diagram of the host computer interface of the present invention;

Fig. 4 is the host computer interface data setting diagram of the present invention;

FIG. 5 is a physical diagram of an electronic board card of the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

According to an embodiment of the present invention, a driving device suitable for remote control of the luminous intensity of laser diodes in environments with large temperature changes is proposed, which can be applied to the research field of luminous intensity control of laser diodes. The device can control the luminous intensity of the laser diode, communicate with the host computer and other functions. Specific requirements such as device scalability and maintenance convenience.

According to an embodiment of the present invention, a laser diode driving device that can be remotely controlled in a wide temperature change environment includes an external support structure made of aluminum material, an RS232 interface for communication with a host computer, a USB interface for power supply, and a Raymo connector to connect the laser The module connecting the diode and the board has I/V conversion circuit, ADC, FPGA, DAC circuit and constant current source circuit output board, as shown in Figure 5, which is the physical picture of the electronics board.

The input and output signals and power interface of the electronic board for controlling the luminous intensity of the laser diode are designed on the side of the aluminum shell.

In the electronic board for controlling the luminous intensity of the laser diode, the laser diode PD sends out a monitoring current, converts the current signal into a voltage signal and amplifies it through the I/V conversion circuit, collects and outputs it to the FPGA through the ADC, and passes the FPGA power compensation module. Select different modes to control the luminous intensity of the laser diode, and output the voltage through the DAC to the constant current source circuit to make the output current a constant value to supply power to the laser diode.

The electronic board for controlling the luminous intensity of the laser diode can choose to use the FPGA power compensation module to adjust the luminous intensity of the laser diode through the PD current feedback signal, or the operator can actively control the laser diode through the host computer to adjust the driving current of the laser diode to control the laser. The luminous intensity of the diode. As shown in FIG. 2 , it is a structural diagram of the internal modules of the FPGA of the present invention.

The electronic board for controlling the luminous intensity of the laser diode communicates with the host computer through the RS232 interface. The electronic board can be controlled by selecting the mode and setting the current size and limit value through the host computer, and the FPGA can be seen through the host computer interface. The transmitted logical bytes, as shown in Figure 3-4, are the control interface of the host computer of the present invention.

Under different temperature conditions, the feedback current of the PD pin of the laser diode will change. The electronic board that controls the luminous intensity of the laser diode achieves the driving current of the laser diode by collecting the feedback current change of the PD pin. adjustment, so as to realize the compensation of the luminous intensity of the laser diode.

As shown in FIG. 1 , the working principle of the device of the present invention is as follows: sending out a monitoring current for the laser diode PD, converting the current signal into a voltage signal and amplifying it through an I/V conversion circuit, collecting and outputting it through the ADC, and selecting it through the FPGA. Control the luminous intensity of the laser diode, collect the output signal of the FPGA through the DAC, and output the voltage to the constant current source circuit to make the output current a constant value to supply power to the laser diode. Communication with the host computer through the RS232 interface, you can select the constant current source mode and set the current size and limit value to control the board through the host computer, and you can see the logic bytes transmitted by the FPGA through the host computer interface.

The FPGA power compensation module includes two selection modes, one is constant current source mode and the other is constant power mode. In the constant current source mode, the signal output by the FPGA changes according to the PD feedback current signal; in the constant power mode, the signal output by the FPGA is written by the operator through the host computer. In a temperature-changing environment, the PD feedback current signal will change with the temperature change, and on this basis, the driving current can be adjusted to adjust the luminous intensity.

Although illustrative specific embodiments of the present invention have been described above to facilitate understanding of the present invention by those skilled in the art, it should be clear that the present invention is not limited in scope to the specific embodiments, to those skilled in the art, As long as various changes are within the spirit and scope of the present invention as defined and determined by the appended claims, these changes are obvious, and all inventions and creations utilizing the inventive concept are included in the protection list.

Claims (9)

1. A laser diode drive device that can be remotely controlled in a wide temperature change environment, providing a stable and reliable laser for on-site calibration of ray detectors, the wide temperature range refers to: 20 ℃-45 ℃; The drive device described includes: Aluminum material support structure, choose a laser diode with photosensitive feedback output as the laser source, sample the photosensitive feedback signal PD to monitor the luminous intensity of the laser diode in real time, and the photosensitive feedback signal PD is the current signal flowing through the laser diode. The I/V conversion circuit of the voltage amplifies and converts it into a voltage signal. The ADC collects and converts the analog voltage signal into a digital signal and transmits it to the FPGA. Through the FPGA power compensation calculation, the corresponding digital signal is sent, and the digital signal is converted into an analog voltage signal by the DAC. , the driving constant current source circuit provides the driving current for the laser diode. 2. The laser diode drive device that can be remotely controlled in a wide temperature change environment according to claim 1, wherein: It includes a constant current source circuit that controls the luminous intensity, a PD signal conditioning module with a laser diode photosensitive feedback signal, an ADC sampling module, an FPGA-based power compensation algorithm module, a DAC voltage output module, and an RS232 serial port module that communicates with the host computer. 3. The laser diode drive device that can be remotely controlled in a wide temperature change environment according to claim 1, wherein: The FPGA is used to control the constant current source to send out a narrow pulse current signal, the narrowest pulse is less than 100ns, and the narrow pulse laser signal is used for the measurement of the response rate of the detector, and the noise floor and baseline offset of the detector are measured at the same time; FPGA can realize fast self-calibration function, convert analog signal from ADC to digital signal after processing by FPGA, and then convert it into analog signal by DAC. 4. The laser diode driving device that can be remotely controlled in a wide temperature change environment according to claim 1, wherein: Remotely configure the drive current, working mode, limit current, and limit voltage parameter settings of the laser diode through the host computer, monitor and display the PD current of the photosensitive feedback signal in real time, and set the working limit protection parameters to avoid the laser diode during use due to overcurrent or damage caused by overvoltage; There are two operating modes for controlling the laser diode, one is the constant optical power mode, and the other is the constant driving current mode. 5. The laser diode driving device that can be remotely controlled in a wide temperature change environment according to claim 1, wherein: Use FPGA to exchange information with the host computer through 232 communication, change the current supplied to the laser diode LD in real time and the data accuracy is at the thousandth level, real-time check the operating status of the laser diode LD, including the input current provided to the laser diode LD, photosensitive feedback The feedback current of the signal PD is collected and displayed in real time, and the data accuracy is at the thousandth level. The operation mode of the laser diode can be switched online, and the current limiting protection peak value of the laser diode can be changed online. 6. The laser diode driving device that can be remotely controlled in a wide temperature change environment according to claim 1, wherein: The device is connected to the laser diode using the Remo connector, which increases the maintenance efficiency. At the same time, the device is small in size: 104mm×76mm×46mm. It can work normally by supplying power through the miniUSB 5V interface, which is convenient for the on-site calibration of the ray detector. 7. The laser diode driving device that can be remotely controlled in a wide temperature change environment according to claim 1, wherein: The input and output signals and power interface of the electronic board for controlling the luminous intensity of the laser diode are designed on the side of the aluminum shell. 8. The laser diode driving device that can be remotely controlled in a wide temperature change environment according to claim 1, wherein: The electronic board that controls the luminous intensity of the laser diode communicates with the host computer through the RS232 interface, selects the mode and sets the current size and limit value to control the board through the host computer, and sees the logic word transmitted by the FPGA through the host computer interface Festival. 9. The laser diode drive device that can be remotely controlled in a wide temperature change environment according to claim 1, wherein: Under different temperature conditions, the feedback current of the PD pin of the laser diode will change. The electronic board that controls the luminous intensity of the laser diode controls the driving current of the laser diode by collecting the feedback current change of the PD pin. Adjustment to achieve compensation for the luminous intensity of the laser diode.

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