Multi-wavelength tunable lasers for gas spectroscopy

在过程工业、环境和医疗应用中，同时快速测量多种气体的浓度，以提供实时信息是很重要的。例子包括;-测量燃烧原料和排放气体，这对减少碳排放很重要。-检测天然气工业和沼气生产工业中的碳氢化合物和硫化氢-检测工业中的有毒物质，如氨和氟化氢-呼吸气体诊断，诊断和管理哮喘、糖尿病、肾病、囊性纤维化等疾病。-测量短寿命气体种类，以改善城市空气质量，了解影响气候变化的重要大气过程。这些活动给工业用户带来了重大的测量问题。工业气体检测主要由复杂和昂贵的实验室设备进行采样，这妨碍了实时测量，甚至可以通过样品管道中的冷凝和/或反应影响样品的组成。小型的超低成本设备也可用，但是这些设备不能提供工业应用所需的稳定性和气体种类特异性。许多感兴趣的气体吸收光谱中近红外区域（1.3 - 2.5微米）特定和特征波长的光。使用一个合适的激光源，其发射波长是已知和可控的，这种特性构成了检测气体和测量其浓度的强大方法的基础。我们的光学气体检测新方法，基于一种新型光源的开发，将实现多物种检测以及不稳定物种的检测，这两种检测都是现有技术难以实现的。这些来源的演示将首先包括碳氢化合物，二氧化碳和一氧化碳的检测，然后导致不稳定的物种，如硫化氢和氨的测量。

In process industry, environmental and medical applications, it can be important to measure the concentration of many gas species simultaneously and rapidly, to give real-time information. Examples include; - Measurement of combustion feedstocks and effluent gases, important in the drive for reduced carbon emissions. - Detection of hydrocarbons and hydrogen sulfide in the natural gas industry and biogas generation industries - Detection of toxic species in industry, such as ammonia and hydrogen fluoride - Breath gas diagnostics, to diagnose and anage diseases such as asthma, diabetes, renal disease, cystic fibrosis and others. - Measuring short-lived gas species, to improve urban air quality and understand important atmospheric processes affecting climate change. These activities present a significant measurement problem to industrial users. Industrial gas detection is dominated by complex and expensive laboratory equipment with sampling that precludes real-time measurement and can even affect the composition of the sample through condensation and / or reaction in the sample pipework. Small ultra-low-cost devices are also available, however these do not offer the stability nor the gas species specificity needed for industrial applications. Many gases of interest absorb light at specific and characteristic wavelengths in the near infrared region of the spectrum (1.3 - 2.5 microns). Using a suitable laser source whose emission is at known and controlled wavelengths, this property forms the basis of a powerful method to detect gases and measure their concentrations.Our new approach to optical gas detection, based on development of a new class of optical sources, will enable both multi-species detection as well as detection of unstable species, both of which are difficult to impossible with existing technology. Demonstration of these sources will initially include detection of hydrocarbons, carbon dioxide and carbon monoxide, then lead on to measurement of unstable species such as hydrogen sulfide and ammonia..