Dual-channel Fiber Loop Ring Down Spectroscopy Microend Pressure Sensor

Fiber loop ring down spectroscopy (FLRDS) is a novel and sensitive absorptionspectroscopy. This method has been inspired by the popular cavity ring downspectroscopy (CRDS), but with a loop of optical fiber forming the high-finesse cavityrather than two highly reflective mirrors. FLRDS has many advantages. Losses of lessthan 0.1% can be measured quantitatively with FLRDS and it is now used in applicationsthat range from analyses of trace concentration and single cell to sensing of strain,pressure and temperature. This new technique should find widespread use in thecharacterization of environment as well as in novel bio-chemical detection schemes. Asfar as know, FLRDS can only measure single sample or physical parameter. In this thesis,we present dual-channels FLRDS sensors, taking full advantage of the principle of thetime division multiplexing. The sensor is successfully applied to acquire both positionspressure at the same time. The experimental results indicate that the sensor has a fastresponse to the pressure changes as well as a good stability. The results also demonstratethat the sensor displays not only a linear response to applied forces but also a goodrepeatability. What is more, owing to its characteristic of synchronous, a variety ofpotential application can be expected.