Optical Fibre Sensors for high Sensitivity Gas Detection

用于高灵敏度气体检测的光纤传感器

• 批准号: EP/D054591/1
• 负责人: Brian Culshaw
• 金额: $ 59.2万
• 依托单位: University of Strathclyde
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2006
• 资助国家: 英国
• 起止时间: 2006 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FD054591%2F1
• 关键词: Optical; Fibre; Sensors; Sensitivity; Gas

Near infra-red (IR) tuneable diode laser spectroscopy (TDLS) has become a powerful technique in many areas of gas sensing. In particular, interest in TDLS over optical fibre is growing for remote (sometimes multi-point) applications in difficult or hazardous environments / locations. The overall aim of this project is to enhance the sensitivity of TDLS over optical fibre by three to four orders of magnitude to enable its application to the detection of trace gases such as toxins, nerve gases or other species that may represent a security threat and vapour by products of the decomposition of explosives or other hazardous chemicals. A dual approach will be adopted. The first is a relatively low risk approach to gaining two to three orders of magnitude enhancements in the near IR system through careful optical design and enhanced optical and electronic signal processing to eliminate etalon fringes and improve the signal to noise ratios. In the second, more radical, approach we will investigate the use of guided wave, non-linear CW parametric difference frequency generation (DFG) devices at the remote gas cell to generate mid IR idler wavelengths from near IR pump and signal waves transmitted over optical fibre. This will enable, for the first time, the much stronger (by 2 / 3 orders of magnitude) mid IR fundamental absorption lines to be addressed using TDLS over optical fibre. A variation of the basic DFG technique / the singly resonant optical parametric oscillator - will enjoy all the benefits of signal modulation (TDLS techniques), optical fibre transmission, recovery and detection in the near IR, whilst exploiting the sensitivity gains associated with the much stronger fundamental absorption lines of the mid IR. Sensitivities well below the part per billion level are anticipated.

近红外 (IR) 可调谐二极管激光光谱 (TDLS) 已成为气体传感许多领域的一项强大技术。特别是，对于困难或危险环境/地点中的远程（有时是多点）应用，人们对光纤 TDLS 的兴趣与日俱增。该项目的总体目标是将光纤上的 TDLS 灵敏度提高三到四个数量级，使其能够应用于检测微量气体，例如毒素、神经毒气或其他可能构成安全威胁的物质，以及爆炸物或其他危险化学品分解的蒸气副产物。将采用双重方法。第一种是风险相对较低的方法，通过仔细的光学设计和增强的光学和电子信号处理来消除标准具条纹并提高信噪比，从而在近红外系统中获得两到三个数量级的增强。在第二种更激进的方法中，我们将研究在远程气室中使用导波、非线性 CW 参数差频发生 (DFG) 设备，从近红外泵浦产生中红外闲频波长，并通过光纤传输信号波。这将首次能够使用光纤上的 TDLS 来解决更强（2 / 3 个数量级）的中红外基本吸收线。基本 DFG 技术/单谐振光学参量振荡器的变体 - 将享受近红外信号调制（TDLS 技术）、光纤传输、恢复和检测的所有优势，同时利用与中红外更强的基本吸收线相关的灵敏度增益。预计敏感性远低于十亿分之一的水平。

项目成果

Influence of the wavelength-dependence of fiber couplers on the background signal in wavelength modulation spectroscopy with RAM-nulling.

• DOI: 10.1364/oe.18.000267
• 发表时间: 2010-01
• 期刊: Optics express
• 影响因子: 3.8
• 作者: A. Chakraborty;K. Ruxton;W. Johnstone

Chemical Sensor Networks for Gas Detection and Environmental Monitoring

用于气体检测和环境监测的化学传感器网络

• DOI: 10.2174/157341108785914853
• 发表时间: 2008
• 期刊: Current Analytical Chemistry
• 影响因子: 1.8
• 作者: Duffin K