中文摘要：

在察觉到的近红外线的 H2O 的领域里，吸收信号的获得通常从一个吵闹的背景，这样采用一个有效信号解调方法是重要的。这研究在踪迹水蒸汽察觉的领域里介绍了研究进步，盖住不同单个煤气的察觉技术。根据常规双横梁，微分吸收，在电压的部门方法和基于二根邻近的吸收线的微分价值的双山峰的方法被学习了。电压分割有优秀稳定性到温度变化，机械挤出，和纤维拐弯损失。双山峰的方法与水蒸汽集中证明了一种线性关系，并且这个方法提供了一个方法在高压力测量集中。而且，所谓的平衡 ratiometer 察觉(BRD ) 被介绍。它一个突出的自动调节的能力，和它能也避免变换电路的 current-to-voltage 引起的过量阶段差别，因此，这个方法有高敏感。另外，用于煤气的察觉的第二种泛音技术被介绍，并且为经由驾驶电流的高周波的调整， 1/f 显然被压制；作为结果，这种技术由一～二个数量级认识到更好敏感的察觉。

英文摘要：

In the field of near infrared H2O sensing, the acquisition of the absorption signal usually is from a noisy background, thus it is important to adopt an effective signal demodulation method. This study introduced the research progress in the field of trace water vapor detection, covering different individual gas detection techniques. On the basis of the conventional double-beam differential absorption, the division method in voltage and the dual-peak method based on the differential value of two adjacent absorption lines have been studied. Voltage division has an excellent stability to temperature variation, mechanical extrusion, and fiber bend loss. The dual-peak method proved a linear relation with the water vapor concentration, and this method provided a way to measure the concentration at high pressure. Furthermore, the so called balanced ratiometer detection （BRD） was introduced. It has an outstanding self-adjusting capability, and it can also avoid an excess phase difference caused by the current-to-voltage converting circuit, thus this method has a high sensitivity. In addition, the second harmonic technique applied to gas detection was introduced, and for the high-frequency modulation via driving current, l/f was suppressed apparently; as a result, this technique realized a better sensitive detection by one to two orders of magnitude.