CN210957267U

CN210957267U - High-speed low-noise laser driving circuit for scanning laser light source

Info

Publication number: CN210957267U
Application number: CN201921985973.XU
Authority: CN
Inventors: 李苗; 高阳; 段亮宏; 江剑军; 刘刚; 万生鹏
Original assignee: Jiangxi Xufeng Photoelectric Technology Co ltd
Current assignee: Jiangxi Xufeng Photoelectric Technology Co ltd
Priority date: 2019-11-18
Filing date: 2019-11-18
Publication date: 2020-07-07
Anticipated expiration: 2029-11-18

Abstract

The utility model provides a high-speed low noise laser instrument drive circuit for scanning laser light source, it is including FPGA module, DA converter, the semiconductor laser who connects gradually to and the temperature controller who is connected with the semiconductor laser. The FPGA module is a control core and outputs data in a form of binary digital quantity; the D/A converter is connected with the FPGA module, converts the binary digits into analog current signals and drives the semiconductor laser; the temperature controller is connected with the semiconductor laser, compares the difference value between the working temperature and the actual temperature of the semiconductor laser, enables the actual temperature to be equivalent to the working temperature through a semiconductor refrigeration technology, and keeps stable output of the semiconductor laser.

Description

High-speed low-noise laser driving circuit for scanning laser light source

Technical Field

The utility model relates to a laser instrument control technical field, concretely relates to a drive circuit for laser instrument.

Background

With the increasing maturity of semiconductor technology, semiconductor Lasers (LDs) have increasingly been widely used in the fields of scientific research, industry, military, medical treatment, etc. due to their characteristics of high conversion rate, small size, light weight, high reliability, and direct modulation. The stability of a semiconductor laser depends on the driving power supply, and the fluctuation of current causes the change of optical power, thereby affecting the performance of the laser.

The existing design schemes of the LD driving power supply mainly comprise an analog circuit control scheme, a digital scheme controlled by a single chip microcomputer and the like, wherein the analog circuit control scheme is simple and easy to realize, but has poor anti-jamming capability; the scheme using the single chip microcomputer as a control core improves the anti-interference capability of the LD driving power supply, and can conveniently expand functions, which is the most extensive mature scheme at present. However, the working mode of the single chip determines that the single chip has the problems of crash, possible program flight and the like, and also has the problems of complex design, low control speed and the like, thereby having adverse effects on the service life of the LD.

Disclosure of Invention

In order to solve the problem that the traditional laser drive circuit system is with high costs, the system is complicated, speed is slow, the utility model provides a high-speed low noise laser drive circuit for scanning laser light source.

A high speed, low noise laser driver circuit for a scanning laser light source, comprising:

an FPGA module;

the D/A converter (DAC for short) is connected with the FPGA module and used for converting a digital signal into an analog signal;

a semiconductor laser connected to the D/A converter for generating laser light;

and the temperature controller is connected with the semiconductor laser and used for controlling the temperature of the semiconductor laser.

Further, the FPGA module is an Artix-7 series device XC7A100T from xilinx corporation.

Furthermore, the semiconductor laser adopts a butterfly-shaped packaged laser, and a thermistor and a refrigerator are integrated inside the semiconductor laser.

Further, the temperature controller employs a monolithic temperature controller for a Peltier thermoelectric cooler (TEC) module.

The utility model has the advantages that: the FPGA and DAC structure is adopted, the FPGA is used as a control core, the FPGA is used for outputting required digital quantity, the digital quantity is converted into current through the DAC, and the current is directly driven to the semiconductor laser, so that full digitalization of a control system can be realized, the anti-interference capability of the system is improved, and the working adaptability under high and low temperature environments and more complex electromagnetic environments is enhanced; the high-speed conversion is realized, the conversion precision is high, the crash is avoided, the control speed is high, and the efficiency is high; simple structure and low cost.

Drawings

Fig. 1 is a schematic structural diagram of a high-speed low-noise laser driving circuit for scanning a laser light source according to the present invention.

The reference signs explain: 100, FPGA module, 200, D/A converter, 300, semiconductor laser, 400, temperature controller.

Detailed Description

The present invention will be further described with reference to the accompanying drawings and specific embodiments.

As shown in fig. 1, the present invention relates to a high-speed low-noise laser driving circuit for scanning laser light source, which comprises an FPGA module 100, a D/a converter 200, a semiconductor laser 300, and a temperature controller 400 connected to the semiconductor laser 300.

The FPGA module 100 is used for driving the D/A converter 200. In the embodiment, the FPGA module 100 adopts an Artix-7 series device XC7A100T of xilinx company, adopts miniaturized packaging, and can meet the performance requirements of low-cost mass markets.

The FPGA device is a hardware reconfigurable system structure, is a programmable logic array, contains rich logic units inside, and has a basic structure comprising a programmable input/output unit, a configurable logic block, a digital clock management module, an embedded block RAM, a wiring resource, an embedded special hard core and a bottom embedded functional unit. The FPGA has the characteristics of abundant wiring resources, high repeatability and integration level and low investment, and is widely applied to the field of digital circuit design. Meanwhile, the function of each logic unit of the FPGA is determined when the FPGA is reprogrammed, and no instruction is needed, so that the running speed of the FPGA is higher than that of a CPU (central processing unit).

The D/a converter 200 is connected to the FPGA module 100 for converting the digital signal into the analog signal. The digital-to-analog converter has two conversion modes: parallel digital-to-analog conversion and serial digital-to-analog conversion. Serial digital-to-analog conversion is the conversion of a digital quantity into a number of pulse sequences, one pulse being equivalent to one unit of the digital quantity, and has the advantages of fewer pins and low speed. One pulse of the parallel digital-to-analog conversion is equivalent to the whole digital quantity, and the advantages are that the number of pins is large, and the speed is high. In this embodiment, the D/a converter 200 is a current-mode, parallel, 16-bit digital-to-analog converter, and the update rate is 100MSPS, which meets the requirements for speed and accuracy.

D/a converters, also known as digital-to-analog converters, DACs for short, are devices that convert digital quantities into analog. The DAC mainly comprises a digital register, an analog electronic switch, a bit weight network, a summing operational amplifier and a reference voltage source (or constant current source). Common DACs mainly include full-resistor network DACs, T-type resistor network DACs, inverted-T-type resistor network DACs, weight-current DACs, and the like. The weight resistance network DAC is characterized by simple structure and less used resistance elements; but the resistor has many types, the resistance value difference of the resistor is large, and the precision is not easy to guarantee. The characteristic of the T-type resistance network DAC is that the output is only related to the resistance ratio, but each branch of the resistance network has transmission time difference, which is easy to cause dynamic error and has great influence on the conversion precision and speed. The weight current type DAC is characterized in that a constant current source is introduced, the nonlinear error caused by the conduction resistance and the conduction voltage drop of an analog switch is reduced, the current directly flows into the input end of the operational amplifier, the transmission time is short, and the conversion speed is high.

The semiconductor laser is a power consumption type active device, and the output characteristics of the semiconductor laser are obviously affected by temperature change in the working process, so that the temperature needs to be controlled.

The temperature controller 400 is connected to the semiconductor laser 300 and controls the temperature of the semiconductor laser 300. In this embodiment, the temperature controller 400 is a semiconductor cooling plate, which has the advantages of no sliding parts, and can be applied to the occasions with limited space, high reliability requirement and no refrigerant pollution. By utilizing the Peltier effect of semiconductor materials, when direct current passes through a galvanic couple formed by connecting two different semiconductor materials in series, heat can be absorbed and released at two ends of the galvanic couple respectively, so that the aim of refrigeration can be fulfilled; and the external elements are reduced as much as possible while high efficiency is provided, so that the whole system is simpler and lower in cost.

The FPGA module 100 is a control core, and outputs data in the form of binary digital quantity; the D/a converter 200 is connected to the FPGA module 100, converts binary digits into an analog current signal, and drives the semiconductor laser 300; the temperature controller 400 is connected to the semiconductor laser 300, compares a difference between an operating temperature of the semiconductor laser 300 and an actual temperature, matches the actual temperature to the operating temperature by a semiconductor refrigeration technology, and maintains a stable output of the semiconductor laser 300.

One of the most important means of the current digital system is FPGA, and an FPGA device belongs to a semi-custom circuit in an application-specific integrated circuit, is a programmable logic array, and can effectively solve the problem of less circuits of the original case gate. After the FPGA device is programmed, a corresponding hardware circuit is generated, the system can work after being electrified, the control speed is high, and the efficiency is high; the anti-interference capability of the system is improved through full digitalization.

Claims

1. A high speed, low noise laser driver circuit for a scanning laser light source, comprising:

an FPGA module;

the D/A converter is connected with the FPGA module and is used for converting a digital signal into an analog signal;

2. A high speed low noise laser driver circuit for scanning laser light sources as claimed in claim 1 wherein the FPGA module is an Artix-7 series device XC7a100T from xilinx corporation.

3. A high speed low noise laser driver circuit for a scanning laser light source as claimed in claim 2, wherein said temperature controller employs a monolithic temperature controller for a Peltier thermoelectric cooler module.