32通道光纤阵列式高灵敏飞秒激光光谱分析仪

发布时间：2018-01-12 10:03

本文关键词：32通道光纤阵列式高灵敏飞秒激光光谱分析仪　出处：《光电子·激光》2015年01期 　论文类型：期刊论文

【摘要】：针对飞秒激光光谱学研究中对微弱光信号的多通道光谱分析的需求,提出了一种32通道光纤阵列-锁相放大光谱分析仪(OSA)设计方案。32通道光纤阵列用于传输线型分布光谱信号,经光电探测器(PD)转换的电信号由32通道同步数字锁相放大器进行处理。基于现场可编程门阵列(FPGA)设计的32通道同步数字锁相放大器,实现了各路独立的微弱光谱信号同时检测功能。针对飞秒激光光谱测量中重复频率为1kHz的强干扰,设计1kHz陷波器,提高信号测量的动态范围。设计的OSA的测量光谱范围为400~1100nm,通道光谱间隔为4nm。实验结果表明:32通道光纤阵列OSA的通道隔离度大于80dB,输入光噪声密度为37.9fW/i酘z,各通道极限检测灵敏度可达18.9fW,动态储备达到120dB。应用于飞秒时间分辨荧光光谱测量,对超荧光干扰抑制效果明显,同时极大地提高了测量灵敏度并缩短动力学测量时间至6 min。本文实现的OSA具有灵敏度高、体积小和性价比高等优点,适用于对微弱光谱信号的高灵敏与快速检测分析。
[Abstract]:The multichannel spectral analysis of weak light signals is required in femtosecond laser spectroscopy. This paper presents a design scheme of 32-channel fiber array-phase-locked amplified spectrometer (OSA). The 32-channel fiber array is used for transmission line distributed spectral signal. The electrical signal converted by the photodetector is processed by the 32 channel synchronous digital phase-locked amplifier, and the 32 channel synchronous digital phase-locked amplifier is designed based on FPGA (Field Programmable Gate Array). All independent weak spectral signals can be detected simultaneously. A 1kHz notch filter is designed for the strong interference of 1kHz repetition rate in femtosecond laser spectral measurement. The dynamic range of signal measurement is improved. The measured spectral range of the designed OSA is 400 ~ 1100nm. The spectral interval of the channel is 4 nm. The experimental results show that the channel isolation of the OSA is greater than 80 dB, and the input optical noise density is 37.9 fW / Iz. The limit detection sensitivity of each channel can reach 18.9 fW and the dynamic reserve reaches 120 dB. It has been applied to femtosecond time-resolved fluorescence spectrum measurement and has obvious effect on suppressing superfluorescence interference. At the same time, the measurement sensitivity is greatly improved and the kinetic measurement time is shortened to 6 mins. The OSA realized in this paper has the advantages of high sensitivity, small volume and high performance-to-price ratio. It is suitable for high sensitive and fast detection and analysis of weak spectral signals.
【作者单位】：大连理工大学物理与光电工程学院;
【基金】：国家自然科学基金(51277021,61137005);国家自然科学青年科学基金(61307105)资助项目
【分类号】：TH744.5
【正文快照】： 1引言在飞秒激光光谱、拉曼光谱和荧光光谱测量等领域的研究中,需要利用光学多通道同步测量技术得到光谱分布信息[1,2]。在信号光极其微弱的情况下,信号往往被淹没在背景噪声中,采用CCD光谱分析仪(OSA)进行长时间积分测量[3,4],不仅响应速度慢,也难以获得令人满意的信噪比。在

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