METHOD OF EXPANDING MEASUREMENT RANGE IN DISTRIBUTION TEMPERATURE SENSOR USING LIGHT WAVELENGTH DETECTION METHOD

摘要

PPROBLEM TO BE SOLVED: To achieve a distribution type temperature sensing system having performance in which dynamic range is 5,000 or more, light amount variation is 0.5 nW or more by a light reception element with variation of 0.1 pm of wavelength from the sensor, and the number of sensors connectable to the system is 100 or more at 50 nm of bandwidth of C band, the performance extremely surpassing those of conventional distribution type temperature sensing systems. PSOLUTION: The sensor is constituted by connecting a Bragg grating to a drop port of a double ring resonator. Incident/emitting ports of the sensor are used as resonator incident/emitting ports. Light from a wide band light source is incident on a sensor group in which the plurality of sensors are connected. The reflected light is detected by a wavelength detector using an interferometer such as a Fabry-Perot interferometer in which a resonant wavelength is variable by an electric signal. Accordingly, it extremely surpasses the performance of the conventional distribution type sensing systems in both aspects of the dynamic range and the number of multiplicity (number of sensors connectable to the system). PCOPYRIGHT: (C)2009,JPO&INPIT