Study On The System Of Optical Fiber Temperature Measurement Based On Fluorescence Lifetime

The fluorescence optical fiber temperature sensor is one of the interested problems that are researched in the field of modern optical fiber sensor technology. The situations of measurement temperature are specially, it is difficult to measure temperature for them, and so the other temperature sensor is searched in all research. The virtues of the fluorescence optical fiber temperature sensor are electromagnetic interference resisting, little bulk, low transmission loss, corrosion resisting. More and more attention is put on the fluorescence optical fiber temperature sensor.Based on thoroughly analyzing research present situation in home and abroad, the double-channels optical fiber temperature sensor based on fluorescence lifetime is purposed. It is the aim that the fluorescence optical fiber temperature sensor realizes real time measurement temperature in special environment.The basic principle and characteristic of fluorescence measurement method are discussed, and the total scheme of fluorescence optical fiber measurement temperature system is designed.Based on the fluorescence specific properties of ruby crystal are analyzed, excitation light source, optical filter and optical detector are used reasonably. The system uses the yellow green exceeded shine luminescence diode as the excited light source. The transmission channel of light signal is the low loss silicon optical fiber bundle. The coupling between optical fiber with light source and optical detector are simply analyzed in order to provide foundation for the reasonable selection of excitation and receiving optical fiber.A novel method for the detection of fluorescence lifetime that uses the technology of the phase-locked loop is proposed. With phase-sensitive detection technique and modulation technique in this scheme, the measured fluorescence lifetime is converted to a repetitive signal whose period is directly proportional to it.The system of fluorescence measurement uses the silicon photosensitive three-electrode tube as the detection of fluorescence signal. The 8031singlechip is used to measure fluorescence lifetime.The method of phase-locked measurement temperature based on fluorescence lifetime has been proposed as the main innovation work of this research. The system uses the scheme of double sources that relative to fluorescence signal modulated and phase-locked to measure temperature. The real time measurement of fluorescence lifetime is realized under no exciting light and no interference. This system has higher temperature resolution and response.