Research On The Photonic Crystal Fiber-based Sensors Filled With Metal Nanomaterials

Photonic crystal fiber has become the research focus in the field of sensors with theunique advantages of that it can be designed flexibly and exhibits a high sensitivityfor the change of the filled gas, liquid, metal nanometerials, and liquid crystal and soon. The surface plasmon resonance sensors based on PCF have great potential forapplications in the field of medical detection, biological material detection, foodsafety inspection. This paper has done some work in simulation and experiment. Wehave analyzed the sensor characteristics by changing the structure parameters and thefactors related to the surrounding environment. With the analysis results, the sensorstructures are gradually optimized and related experiments and analysis are alsocarried out.The main contents and innovation points of this diploma work are summarized asfollows:1. This part mainly introduces the fiber sensor and its development. And we focuson the characteristics, applications and the development of the photonic crystal fiber,especially the PCF-based SPR sensor, as well as the related properties of metalmaterials causing the SPR phenomenon.2. The principle of the SPR sensor based on PCF is introduced in this part. Severalnumerical methods of PCF, the principle and calculated methods are outlined firstly.Then the sensing principle of PCF-SPR sensor is described. All of these provide therelevant theoretical basis for the simulation and experiment of PCF-SPR sensor.3. We designed and analyzed several PCF-based sensors. We have investigated thatthe factors of pitch, amount and the irregularity filling influnced the grapefruit fibersensor. The simulation results showed that the sensitivity and loss are stable when thepitch is larger than2μm. The result about the polymer PCF sensor showed that thechange of the structures of PCF had no effect on sensitivity, which makes themanufacturing simply.4. We designed a novel intra-cavity index SPR sensor based on active PCF. Therefractive index of background material fused silica is1.45. The refractive index (RI)of the Yb3+-doped fiber core is nc=1.58, which can broaden the measurable range ofanalyte. The nanowires and analyte are filled into the channels to achieve activesensing. The numerical analyses show that the different air-filling ratios have different effects on the output power and confinement loss. Furthermore, it will presentdifferent trends with different analyte RI of na>1.45or na<1.45. The intra-cavityphotonic crystal fiber sensing system has great practical value and significance fortheir advantages of compact structure and high sensitivity.5. From the point of view of practical utility, we have done some relatedexperiments with the produced PCF. The simulation analysis has been studied firstly,and we got the loss spectra and some sensing properties by changing the ratios ofliquid and the temperature. Then we implemented some experiments with the sametype of PCF. The results showed that the changed trend is the same as the simulationwith the change of ratios of liquid and temperature.