摘 要

大功率半导体具有内部结构简单、体积小、高效率和寿命长等诸多长处，广泛地应用于科研、通信、国防、工业等众多领域。半导体激光器可以根据激励方式的不一样，分为电注入式、高能电子束激励式和光泵式。半导体激光器的输出光功率的大小和稳定性受到了电流、电压、频率和占空比的影响。电路中的浪涌电流和电网冲击等因素都会很容易损坏半导体激光器的性能，从而影响半导体激光器的使用寿命。

根据不同的应用要求，所需要的输出功率大小也是不一样的。在需要的半导体激光器的输出功率较小的场合，所需的驱动电源的脉冲信号宽度较小，重复频率较低，当要求大功率的输出时，则反之。国外在大功率半导体激光器方面研究时间早，在封装，材料，技术等方面积累了大量的经验，而国内在大功率半导体驱动电源方面的研究要落后不少，难以兼顾到功率、频率和占空比等方面。

现阶段，有以下的设计方案：模拟电路控制方案采用分离元器件设计出半导体激光器驱动电源，其结构简单,非常容易实现，但不容易精准地去控制驱动电源的输出频率、幅度大小、脉冲宽度而且抗干扰的能力不行；基于FPGA的控制数字化方案，具有电路调节方便简单、调节步长小的优点，而且可以准确地调节激光器驱动电源的脉宽和重复频率，但成本高，控制操作复杂。基于单片机控制的设计方案中，提高了半导体激光器驱动电源的抗干扰性能，可以很方便地利用单片机的IO口进行功能扩展。

对目前大功率脉冲光源控制方案的优缺点研究之后，本文设计了基于单片机和ICL8038芯片的脉冲光源的控制电路。通过单片机去控制ICL8038芯片产生脉冲方波的重复频率、脉冲宽度、幅值等参数，经过脉冲调理电路后，去驱动半导体激光器，从而改变其输出光功率的大小。本设计方案实现了脉冲方波的脉宽和重复频率都是可以调节，脉冲方波的幅值是0-12V可调，重复频率是0.001HZ~1MHZ可调，产生占空比为2%~98%的可调波形。一定程度上解决了窄脉冲，高频率，可调节的技术难点。输出功率在30mW到80mW左右。

关键词：大功率半导体 单片机 ICL8038 驱动电路

Abstract

High-power semiconductors have many advantages such as simple internal structure, small size, high efficiency and long life, and are widely used in many fields such as scientific research, communications, national defense, industry and so on. Semiconductor lasers can be divided into electric injection type, high energy electron beam excitation type and optical pump type according to the different excitation methods. The size and stability of the output power of the semiconductor laser are affected by current, voltage, frequency, and duty cycle. The surge current in the circuit and the impact of the power grid will easily damage the performance of the semiconductor laser, thereby affecting the service life of the semiconductor laser.

According to different application requirements, the required output power is also different. When the required output power of the semiconductor laser is small, the pulse signal width of the required driving power source is small, and the repetition frequency is low. When a high-power output is required, the reverse is true. Foreign countries have long research time in high-power semiconductor lasers, and have accumulated a lot of experience in packaging, materials, technology, etc., and domestic research in high-power semiconductor drive power sources is far behind, and it is difficult to take into account power, frequency and duty cycle than other aspects.

At this stage, there are the following design schemes: the analog circuit control scheme uses discrete components to design a semiconductor laser drive power supply, which has a simple structure and is very easy to implement, but it is not easy to accurately control the output frequency, amplitude, and pulse width of the drive power supply Moreover, the anti-interference ability is not feasible; the digital control scheme based on FPGA has the advantages of simple and convenient circuit adjustment and small adjustment step, and can accurately adjust the pulse width and repetition frequency of the laser drive power supply, but the cost is high and the control operation is complicated. In the design scheme based on the single-chip microcomputer control, the anti-interference performance of the driving power of the semiconductor laser is improved, and the function expansion of the IO port of the single-chip microcomputer can be conveniently used.

After studying the advantages and disadvantages of the current high-power pulsed light source control scheme, this paper designs a pulsed light source control circuit based on the single chip microcomputer and ICL8038 chip. Through the single chip microcomputer to control the repetition frequency, pulse width, amplitude and other parameters of the pulse square wave generated by the ICL8038 chip, after the pulse conditioning circuit, the semiconductor laser is driven to change the size of its output optical power. The pulse width and repetition frequency of the generated pulse square wave can be adjusted as needed. The amplitude of the pulse square wave is adjustable from 0-12V, the repetition frequency is adjustable from 0.001HZ to 1MHZ, and the duty cycle is 2% ~ 98% adjustable waveform. To a certain extent, it solves the technical difficulties of narrow pulse, high frequency and adjustable. The output power is about 30mW to 80mW.

Key words: high power semiconductor Single chip microcomputer ICL8038 drive circuit

目录

摘要 I

Abstract II

1绪论 1

1.1本课题研究背景及意义 1

1.2半导体激光器的国内外研究现状 1

1.3本课题的主要研究内容及结构安排 3

2半导体激光器的工作条件及特性 4

2.1半导体激光器工作条件 4

2.2半导体激光器基本特性 5

2.3驱动电路的主要要求 7

3方案选择 8

4大功率脉冲光源的硬件设计 9

4.1系统总体设计 9

4.2电源系统的设计 10

4.3 ICL8038脉冲产生电路 11

4.4脉冲信号调理电路 14

4.5大功率脉冲光源的系统构成 15

4.6大功率脉冲光源控制电路 16

5大功率半导体光源驱动电路的仿真结果与验证 20

6总结与展望 23

参考文献 24

致谢 25

附录 26

1绪论

1.1本课题研究背景及意义

美国科学家Chaeles Townes和Artuur Schawlow发现这样的一种现象，当某种固体分子被氖光击中时，它会发出激光^[1]。随后，各国的激光研究学者开始基于这一现象开始对激光器做各种研究，很多年后，才有科学家设计出能够发射激光的电路方案，他们采用的固体介质是红宝石，在成功开发和生产了这种激光器之后，因为其出色的方向性和光谱的单一性，它越来越多地用于通信、医药、军事、工业生产和加工中。

按照所采用的工作介质来区分，激光器包括固体、液体、气体以及半导体激光器^[2]。其中，半导体激光器的工作介质是半导体材料，具有制造简单，成本低廉，转换效率高和重量轻的优点。大功率半导体激光器的一个共同缺点是价格昂贵，而且发射的激光性能在很大程度上受到其驱动电源的影响，因此，设计一个大功率脉冲光源需要一个稳定的驱动电源。半导体激光器的驱动方式主要有以下三种:恒功率控制型、恒压控制型、恒流控制型^[3]。多个国家和地区的科学研究人员一直在研究如何使用半导体激光器来产生脉冲宽度和频率可以调节的光脉冲信号。本文所研究的驱动电源工作在脉冲方式下，要求驱动电源输出脉冲方波信号，经过脉冲调理电路后去驱动激光器，这种设计方案不仅输出的信号稳定，而且频率和脉冲的幅度可调。

1.2半导体激光器的国内外研究现状

通过在激光器内部结构PN结的两端上加上合适的偏置电压，半导体激光器可以正常工作发射光信号，把电信号转变为了光信号。在恒电流驱动方案中，电流幅值影响输出的功率。但在脉冲驱动的设计方案中，脉冲信号的幅度，频率以及占空比都会决定输出光信号的功率大小。