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Due to its small size and light weight, semiconductor lasers (LDs) are widely used in information, communication, medical and other fields, and combined with electronic devices to achieve monolithic optoelectronic integration. However, LD is easily damaged by the impact of overvoltage, current or static charge [1, 2], and the research of its power supply has received more and more attention. If the output voltage or current waveform quality is not high and there is no effective protection, the performance of the laser will be degraded or damaged. Therefore, it is necessary to design a power supply with excellent performance to ensure safe and stable operation of the LD.

This paper takes the digital integrated circuit as the core and designs a semiconductor laser power supply that can realize intelligent control.

Factors affecting the operation of semiconductor laser LD

The core of a semiconductor laser is that once the PN junction is broken down or the cavity surface is partially destroyed, unbalanced carriers and radiation recombination cannot be generated, and the laser output is reduced or disabled depending on the degree of damage.

The main cause of LD damage is cavity surface contamination and surge breakdown. Cavity surface contamination can be solved by purifying the working environment, and more damage is due to surge breakdown. Surge can cause damage or breakdown of PN junction of semiconductor laser. The causes are many, including: 1 instantaneous current of power switch; 2 shutdown of other power equipment in power grid; 3 lightning; 4 strong electrostatic field. Factors such as high voltage, static electricity, and surge impact in the actual working environment will cause damage to the LD or shorten the service life. Therefore, measures must be taken to protect it.

The traditional laser power supply is realized by pure hardware circuit, using analog control method [2, 3]. Although it can drive laser well, it can not achieve precise control. It reduces accuracy and automation in many industrial applications. The application of lasers. The use of a single-chip microcomputer to control the laser power supply can simplify the hardware structure of the laser power supply and effectively solve the problems of accuracy, stability, and reliability of the semiconductor laser. With the rapid development of large-scale integrated circuit technology, the reliability of power supply can be greatly improved by using a chip suitable for LD [4, 5].

system design

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