数字式激光器驱动器的设计与实现
摘要
随着科学技术的飞速发展,半导体激光器越来越广泛地应用于工业生产、高新技术产业及科学研究的各个领域。而激光器的驱动技术也就变得十分重要。因此对激光器驱动技术的研究有着十分深远的意义。本文就是在这一背景下,为了满足激光器产品对驱动器的需求而设计了一款数字式半导体激光器驱动器。
本文以单片机STN89C51为核心,通过C语言编程,结合半导体激光器的工作特点和要求进行设计,系统具有恒流和恒功率两种工作模式,同时还设计了限流保护、浪涌冲击保护、和延时软启动保护待三种保护电路,保证了激光器的安全工作,提高了激光器的使用寿命。最后经实验测试,最大输出电流达到2.5A,短期稳定度达到30ppm,长期稳定度达到了38ppm,基本实现了论文预期的设计要求。论文结束时总结了当前的设计存在的不足,并提出了进一步有待改进和提高的设想。
With the rapid development of science and technology, the techniques of semiconductor laser diode have been applied widely in many fields including industry, high tech and science research. Semiconductor laser diode has the excellent character of high efficiency, small size, low weight, high reliability and direct modulation. But semiconductor laser diode is a kind of device with high power density and sky-high quantum efficiency. Even very little change of drive current or temperature will cause its great change of output light power and device parameters. These problems put forward higher request to the laser diode driver. However, with low control precision, discommodious operation and low safety, the traditional laser diode drivers in home market can not fit the request. So the research on laser diode driver has practical significance. Based on the original analog laser diode driver, this paper designed a digital laser diode driver, which has overcome most of these shortcomings and made up for the deficiencies of the existing products.
In this design, we use both analog circuit and digital circuit. The digital part includes STN89C51 and its control program, whose function is to control the whole system to work in phase. The microcontroller uses the D/A converter to change the digital code to the analog voltage, which provides the input voltage for the constant current source. It also uses the A/D converter to collect and to send back the current parameters of the system to ensure the system work correctly. At the same time, it sends the system status and the output parameters to the LCD screen to display. And the function of limiting current is also realized by the SCM program. The analog part is mainly composed of the constant current source circuit and two protection circuits. The constant current circuit converts the voltage signal to current to drive the laser diode. In the design of the constant current circuit we use two feedbacks: the current feedback and the power feedback. We used a sampling resistance to convert the current to voltage and magnified it to realize the current feedback. The purpose of this feedback is to raise the stability of the output current. We use a photoelectric diode (PD) to realize the power feedback. The PD samples the light power of the laser diode and converts it to proper voltage signal, which is sent back to the feedback port. The purpose of the power feedback is to raise the stability of the light power of the laser diode. In the analog part, we designed two protection circuits: preventing surge circuit and delayed soft-start circuit. The preventing surge circuit uses a relay and a RC charging circuit. The relay is opened when the possible surge impacting time is over, which prevents the possible damage to laser diode efficiently. The soft-start circuit uses the discharge character of the RC circuit to release the input voltage of the constant current source softly from zero to the normal value, which makes the output current raise from zero to the normal value softly. This protection method can avoid the possible damage to the laser diode due to the sudden change of the current.
The whole paper is divided to five chapters. In chapter one, we explain the significant of the research and the development status of the laser diode driver interiorly and overseas. Chapter two is the theory foundation of this paper. In this chapter, we introduce some basic theories of the laser diode and its driver. Chapter three is the holistic explain of the design project. In this chapter, we firstly bring out the system design project and then expound according to the system blueprint. Afterwards we introduce the character of some component including the microcontroller, D/A converter, amplifier and MOS FET. Chapter four is the core part of the paper. In this chapter, we introduce the design and realization of the system in detail. In the hardware part, we introduce the design project and the working principle of the coder circuit, D/A convert circuit and protection circuit etc. In the software part, we introduce the design idea and the flow of main program and sub programs. In the last part of chapter four, we show the character test of the system. We explain in detail the test measure, the using instruments and the test result. In chapter five we conclude the paper and bring out the next research idea.
本文以单片机STN89C51为核心,通过C语言编程,结合半导体激光器的工作特点和要求进行设计,系统具有恒流和恒功率两种工作模式,同时还设计了限流保护、浪涌冲击保护、和延时软启动保护待三种保护电路,保证了激光器的安全工作,提高了激光器的使用寿命。最后经实验测试,最大输出电流达到2.5A,短期稳定度达到30ppm,长期稳定度达到了38ppm,基本实现了论文预期的设计要求。论文结束时总结了当前的设计存在的不足,并提出了进一步有待改进和提高的设想。
With the rapid development of science and technology, the techniques of semiconductor laser diode have been applied widely in many fields including industry, high tech and science research. Semiconductor laser diode has the excellent character of high efficiency, small size, low weight, high reliability and direct modulation. But semiconductor laser diode is a kind of device with high power density and sky-high quantum efficiency. Even very little change of drive current or temperature will cause its great change of output light power and device parameters. These problems put forward higher request to the laser diode driver. However, with low control precision, discommodious operation and low safety, the traditional laser diode drivers in home market can not fit the request. So the research on laser diode driver has practical significance. Based on the original analog laser diode driver, this paper designed a digital laser diode driver, which has overcome most of these shortcomings and made up for the deficiencies of the existing products.
In this design, we use both analog circuit and digital circuit. The digital part includes STN89C51 and its control program, whose function is to control the whole system to work in phase. The microcontroller uses the D/A converter to change the digital code to the analog voltage, which provides the input voltage for the constant current source. It also uses the A/D converter to collect and to send back the current parameters of the system to ensure the system work correctly. At the same time, it sends the system status and the output parameters to the LCD screen to display. And the function of limiting current is also realized by the SCM program. The analog part is mainly composed of the constant current source circuit and two protection circuits. The constant current circuit converts the voltage signal to current to drive the laser diode. In the design of the constant current circuit we use two feedbacks: the current feedback and the power feedback. We used a sampling resistance to convert the current to voltage and magnified it to realize the current feedback. The purpose of this feedback is to raise the stability of the output current. We use a photoelectric diode (PD) to realize the power feedback. The PD samples the light power of the laser diode and converts it to proper voltage signal, which is sent back to the feedback port. The purpose of the power feedback is to raise the stability of the light power of the laser diode. In the analog part, we designed two protection circuits: preventing surge circuit and delayed soft-start circuit. The preventing surge circuit uses a relay and a RC charging circuit. The relay is opened when the possible surge impacting time is over, which prevents the possible damage to laser diode efficiently. The soft-start circuit uses the discharge character of the RC circuit to release the input voltage of the constant current source softly from zero to the normal value, which makes the output current raise from zero to the normal value softly. This protection method can avoid the possible damage to the laser diode due to the sudden change of the current.
The whole paper is divided to five chapters. In chapter one, we explain the significant of the research and the development status of the laser diode driver interiorly and overseas. Chapter two is the theory foundation of this paper. In this chapter, we introduce some basic theories of the laser diode and its driver. Chapter three is the holistic explain of the design project. In this chapter, we firstly bring out the system design project and then expound according to the system blueprint. Afterwards we introduce the character of some component including the microcontroller, D/A converter, amplifier and MOS FET. Chapter four is the core part of the paper. In this chapter, we introduce the design and realization of the system in detail. In the hardware part, we introduce the design project and the working principle of the coder circuit, D/A convert circuit and protection circuit etc. In the software part, we introduce the design idea and the flow of main program and sub programs. In the last part of chapter four, we show the character test of the system. We explain in detail the test measure, the using instruments and the test result. In chapter five we conclude the paper and bring out the next research idea.
引文
[1] David F. Welch,A Brief History of High-Power Semiconductor Laser,IEEE Journal of Selected Topics in Quantum Electronics,2000,6(6):1470～1477。
[2] 王德,李学千,半导体激光器的最新进展及其应用现状,光学精密工程,2001,9(3):279~283。
[3] 韩立新,半导体激光器件应用浅析,电子光器件应用,2000,(8):29~31。
[4] 栖原敏明,周南生,半导体激光器基础,科学出版社,2002:1~11。
[5] 胡宏伟,甘柏辉,胡企铨,半导体激光器电源中的保护技术,应用激光,1998,18(2):81~82。
[6] 姜晓华,陈瑜,准连续大功率半导体激光器电源,长春光学精密机械学院学报,2001 24(9):1~4。
[7] Choosing the right laser diode mount for your application, www.ilxlightwave.com ,Application Note No.6。
[8] 戴特力,半导体激光二极管泵浦固体激光器,第一版,四川大学出版社,1993:5~7。
[9] 陈家璧,激光原理及应用,电子工业出版社,2004:118~119。
[10] 黄章勇,光纤通信用光电子器件和组件,北京邮电大学出版社,2001:22~46。
[11] 吴淑萍,董天临,半导体激光器 P-I 曲线的测定及特性分析,光通信研究,1999,(93):50~54。
[12] 王海林,黄维铃等,二极管激光器运行特性的研究,激光技术,2002,26(1):23~25
[13] 蔡伯荣,陈铮,刘旭,半导体激光器,电子工业出版社,1995:38~49。
[14] 于复生,艾兴,大功率半导体激光器驱动电源的设计,应用激光,2000,20(6):257~260。
[15] 刘澄,半导体激光器的浪涌损坏及其消除方法,电力环境保护,2003,19(4):49~50。
[16] 胡伟,季晓衡,单片机 C 程序设计及应用实例,人民邮电出版社,2003:187~235。
[17] 郑郁正,单片机原理及应用,四川大学出版社,2003:1~3。
[18] 王晓君,安国臣等,MCS-51 及兼容单片机原理与选型,电子工业出版社,2003:1~52。
[19] 张培仁,基于 C 语言编程 MCS-51 单片机原理与应用,清华大学出版社,2003:19~28。
[20] 康华光,陈大钦,电子技术基础模拟部分(第四版),高等教育出版社,1999:168~175,296~305。
[21] 李瀚荪,电路分析基础(中册),高等教育出版社,1993:49~114。
[22] 邓军,单江东,张娜,田小建。大功率半导体激光器恒流源的研究与设计,半导体光电,2003,24(5):319~321。
[23] 单江东,田小建,汝玉星,许健,基于 GPIB 数字繁用表程序控制的设计及应用,实验技术与管理,2008,25(3):80~83。
[24] 姚东明,程愿应,胡兵,大电流连续二极管激光器阵列电源主电路,激光杂志,2003,24(6):14~15。
[2] 王德,李学千,半导体激光器的最新进展及其应用现状,光学精密工程,2001,9(3):279~283。
[3] 韩立新,半导体激光器件应用浅析,电子光器件应用,2000,(8):29~31。
[4] 栖原敏明,周南生,半导体激光器基础,科学出版社,2002:1~11。
[5] 胡宏伟,甘柏辉,胡企铨,半导体激光器电源中的保护技术,应用激光,1998,18(2):81~82。
[6] 姜晓华,陈瑜,准连续大功率半导体激光器电源,长春光学精密机械学院学报,2001 24(9):1~4。
[7] Choosing the right laser diode mount for your application, www.ilxlightwave.com ,Application Note No.6。
[8] 戴特力,半导体激光二极管泵浦固体激光器,第一版,四川大学出版社,1993:5~7。
[9] 陈家璧,激光原理及应用,电子工业出版社,2004:118~119。
[10] 黄章勇,光纤通信用光电子器件和组件,北京邮电大学出版社,2001:22~46。
[11] 吴淑萍,董天临,半导体激光器 P-I 曲线的测定及特性分析,光通信研究,1999,(93):50~54。
[12] 王海林,黄维铃等,二极管激光器运行特性的研究,激光技术,2002,26(1):23~25
[13] 蔡伯荣,陈铮,刘旭,半导体激光器,电子工业出版社,1995:38~49。
[14] 于复生,艾兴,大功率半导体激光器驱动电源的设计,应用激光,2000,20(6):257~260。
[15] 刘澄,半导体激光器的浪涌损坏及其消除方法,电力环境保护,2003,19(4):49~50。
[16] 胡伟,季晓衡,单片机 C 程序设计及应用实例,人民邮电出版社,2003:187~235。
[17] 郑郁正,单片机原理及应用,四川大学出版社,2003:1~3。
[18] 王晓君,安国臣等,MCS-51 及兼容单片机原理与选型,电子工业出版社,2003:1~52。
[19] 张培仁,基于 C 语言编程 MCS-51 单片机原理与应用,清华大学出版社,2003:19~28。
[20] 康华光,陈大钦,电子技术基础模拟部分(第四版),高等教育出版社,1999:168~175,296~305。
[21] 李瀚荪,电路分析基础(中册),高等教育出版社,1993:49~114。
[22] 邓军,单江东,张娜,田小建。大功率半导体激光器恒流源的研究与设计,半导体光电,2003,24(5):319~321。
[23] 单江东,田小建,汝玉星,许健,基于 GPIB 数字繁用表程序控制的设计及应用,实验技术与管理,2008,25(3):80~83。
[24] 姚东明,程愿应,胡兵,大电流连续二极管激光器阵列电源主电路,激光杂志,2003,24(6):14~15。