Measurement And Study On Parameters Of Microstructure Fiber

The characteristic of photonic bandgap in Microstructure Fiber (MSF) isstudied in this dissertation. The method of transmission spectrum is utilized tomeasure the parameters of Photonic Bandgap MSF (PBG-MSF) and RefractiveIndex Guiding MSF (RG-MSF) in different regions. With endless exploration,the measurement equipment is set up, and the photonic bandgaps of PBG -MSFare calculated and analysised by numerical simulation.In theory, The Plane Wave Method (PWM) is researched. The one-dimensional (1D) and two-dimensional (2D) Photonic Crystal (PC) model isdeveloped and used to calculate the energy band structure of 1D and 2D PCbased on PWM method. Especially, the transmission spectra of 2D PC in thetwo cases of in-plane and off-plane are calculated. It is a clear and simple styleby using the energy band structures.In experiments, the measurement equipment of the near-infrared regionbased on the fitting system of the visible light region is set up. So thecharacteristic of the MSF could be analysised from 300 nm to 3 000 nm. Duringthe whole establishing, the intensity of optical source is controlled by theelectrical current of the power supply. To keep the light collimating with thecore of the fibers, the tapered fibers, the transmitting-energy fibers, group oflens and five-dimensional adjusting frame are also utilized. During the datacollection of the light signal, the stability of the photoelectric detector is highlyimproved in the measurement system.During the measurement, two kinds of MSF including hollow-core MSFand single-core, dual-cores and integrated MSF with different parameters aresurveyed. The experimental results indicate that there are several strongtransmission bands in the near-infrared and mid-infrared regions, but hardlyany bandgaps in the visible region, which is consistent with the result oftheoretical computation. The method of measuring the transmission spectrum isproved feasible.