【作者】 张旭；

【导师】 李常青；

【作者基本信息】 郑州大学 ， 电子科学与技术， 2018， 硕士

【摘要】 微弱光信号检测作为光电检测技术的一个分支,以其独特的优势被应用在越来越多的领域。而伴随新技术的发展,性能更好的新器件也层出不穷,进而带动微弱光检测技术的发展。微弱光信号检测中的噪声处理一直是检测技术的关键,常用的检测方法都很复杂,本文将利用微弱光信号的特点,设计一种比较简单的检测系统。首先,本文介绍了微弱光信号检测的背景意义和当前的研究状况。其次,简单分析检测中的噪声成分,给出微弱光检测系统的整体结构,对硬件部分的电路做详细介绍,具体包括光电转换电路、对数放大电路、积分放大电路、以及有单片机控制的AD转换电路、串口通信电路等。并研究对数放大电路的频率特性和放大特性等,实验结果表明,该对数放大电路能很好的实现低频信号的放大,提高信噪比以及压缩信号的动态范围。然后,用C#语言编写上位机软件,实现数据显示、数据处理、数据保存等功能。针对无光照时存在一定的噪声信号,利用信号在硬件电路中的放大关系,编写算法,消除误差。另外,为减小温度对光电转换电路的影响,通过实验利用最小二乘法,建立光电转换电路的温度补偿模型,从而进一步减小微弱光信号检测系统中的误差。最后通过调试使整个系统稳定工作,对实验结果进行分析,针对现阶段的研究状况对未来的研究做一展望。实验结果表明,微弱光检测系统能准确的对微弱光信号进行检测,同时整个系统结构简单、易实现、成本低,检测效果较好,可用于多种场合下的微弱信号检测更多还原

【Abstract】 Weak optical signal detection as a branch of photoelectric detection technology has been applied in more and more fields for its unique advantages.As the development of new technique,the new devices with better performance are emergence,which leads to the development of weak optical signal detection.Noise processing of weak optical signal detection is the key to the detect technology,but the traditional methods of detection are very complex.In this paper,the characteristics of weak optical signal were used to design a simple detection system.Firstly,this paper introduced the background significance and the current research situation of weak optical signal detection.Secondly,the noise component is simply analyzed,and the overall structure of weak optical signal detection system is given.And the hardware part of circuit is described in detail,including photoelectric conversion circuit,logarithmic amplifying circuit and integral amplifying circuit,analog-to-digital conversion circuit and serial communication circuit that are controlled by microprocessor.In addition,the frequency characteristics and amplification characteristics of logarithmic amplification circuit are also studied.The results show that logarithmic amplifying circuit can realize the amplification of low frequency signal,improve signal to noise ratio and compress the dynamic range of signal.Finally,C# language is used to write upper-computer software that could realize data display,data processing and data storage.For the noise signal of darkness,algorithm is written to eliminate error.Otherwise,by using the principle of least square method,the temperature compensation model of photoelectric conversion circuit can be established to reduce the influence of temperature,thus reducing the error in the weak optical signal detecting system.Finally,the whole system is stabled by debugging,and results are analyzed and the future research is prospected.The results show that the weak optical signal detection system can accurate to detect the weak optical signal.At the same time,the whole system structure is simple,easy to implement,low cost,and more effectively detecting,which can be used in a variety of occasions to detect weak signals.更多还原