Study Of Preparation And Phase Measurement Of Layered Photonic Crystals Based On DCG

Photonic crystals are artificial fabricated structures with special characteristics of photonic band gaps,which were put forward in recent years.Due to controlling and manipulating the light wave,it is known as "photonic semiconductor".Photonic crystals materials attract a great deal of attentions from physicists and engineers.Many research groups are committed to producing a variety of excellent photonic crystal devices.However,there are fewer reports based on phase characteristics among many reports about photonic crystals,most of them are based on the amplitude and frequency characteristics.As an important parameter of light wave,it has been found that phase characteristics of photonic crystal are playing crucial role in many physical phenomena and practical applications.So research on the phase characteristics of photonic crystal has important application significance.Based on holographic lithography,layered photonic crystals were prepared by dichromated gelatin(DCG)in this thesis,and the reflection phase of photonic crystals in band gaps were measured by one home-made white light interferometry system.In the first part,the basic concept of photonic crystals,such as the development prospects,research status and fabrication methods were introduced.The phase characteristics of photonic crystals and the potential applications were also analyzed.In the second part,the layered photonic crystals with different periods were fabricated by DCG photosensitive materials based on holographic lithography technology.The band spectrums of the layered structures were measured by the fiber spectrometer.The results show that the layered structure with good band gap can be achieved by DCG materials,and the band gap will shift to longer wavelength with the increase of incident angle of fabrication beam.The layered structures were also characterized by scanning electron microscopy.In the last,based on white light interference,the measuring system of reflection phase was setup,and the phase retrieval method was analyzed with two-beam interference theory.For comparison and analysis,the reflection phase of the uniform glass and the DCG film were measured firstly,then the reflection phase in the band gap of the fabricated layered photonic crystals were measured,the experiment results are consistent with the simulation results.