微弱光信号检测电路的实现  

Implementation of weak optical signal detection circuit

作　　者：李常青[1] 梅欣丽[1,2] 明奇[1] 

机构地区：[1]郑州大学信息工程学院,河南郑州450001 [2]新乡学院物理系,河南新乡453000

出　　处：《应用光学》2010年第5期724-727,共4页Journal of Applied Optics

基　　金：国家自然科学基金资助项目(60678045)

摘　　要：为将微弱光信号有效地转换为电信号以方便后级电路处理,设计了微弱光信号检测电路。电路由光电转换和前置放大两部分组成。光电转换电路采用低输入偏置电流运算放大器AD 549实现;前置放大电路使用对称三极管组成的对数比率放大电路实现,并在同等条件下与集成电路LOG 100组成的前置放大电路相比较。实际测量表明,该放大电路设计可有效放大低于1 nW的微弱输入信号,同时对噪声也有很强的抑制作用,而由LOG 100组成的电路对噪声的抑制能力明显衰减。In order to convert weak optical signals into electrical signals effectively for post-processing,a weak optical signal detection circuit is designed.The circuit consists of a photoelectric conversion circuit and a preamplifier circuit.The photoelectric conversion circuit was implemented with a low input bias current operational amplifier AD549.The preamplifier circuit was implemented with a logarithmic ratio circuit using symmetric transistors,and was compared with the preamplifier composed of IC LOG100 under the same conditions.Measurement results show that the amplifier circuit can amplify weak input signals lower than 1 nW and noise can also be suppressed efficiently,while the circuit composed of LOG100 has a relatively poor performance in noise suppression.

关 键 词：微弱光信号 光电检测 前置放大 对数电路 

分 类 号：TN247[电子电信—物理电子学]