Experimental Research And Theoretical Simulation Of Photonic Crystal Band Gap Structure

In1987E.Yablonovitch and S.John pointed out the conception ofphotonic crystal for the first time on their own. Photonic crystals are thedielectric structure of refractive index periodic change in the spatial. Photoniccrystal can control the transmission of light. So it have attracted greatattention due to their potential scientific value and wide applications.Different methods have been used to research the fabrication techniques，theories and optical properties of photonic lattices by the research groups overthe world，and great progresses have been obtained. Some new preparationmethods, theoretical analysis methods and new type of photonic crystalphotoelectric devices emerge continually.Conventional methods of making photonic crystal has much, includingnatural growth method、mechanical preparation method、mechanical erosionmethod, thin film growth method and so on. But the application and theresearch of photonic lattices is limited because of the traditional fabricationtechniques of photonic lattices has the disadvantages of complicatedtechniques，long fabrication period and small area. In the experiment theall-optical method is used，the all-optical method has a lot of characteristics，including simple operation、low demand for environment、low productioncost、high success rate and so on. These methods include fourier transformmethod, mask imaging method, cross phase method and so on. Becausemaking photonic crystal refractive index of the mediation degree is low, theBragg diffraction band gap is very narrow, so lead that the energy of crystaltransmission is small, its application to it is very limited. In order to improvethe application of photonic crystals, broadening the Bragg angle width of thephotonic crystal is very significant. The main content of this thesis are asfollows:1. Bragg band gap of one-dimensional photonic crystal lattice of broadening were studied in this article firstly. Predecessors have done somework in this respect, they first measured the transmission power of light, thenused these figures to draw lattice band gap. This paper measured thediffraction of light power numerical of photonic crystal lattice for the firsttime, then draw the diffraction efficiency of band gap, this method the resultsmore accurate and effective. In this article photonic crystal，s diffractionefficiency band gap of systemic were researched. In the lab, by changing theamplitude mask hole number, hole spacing and other experimental conditions,then study the photonic crystal lattice，s the diffraction efficiency of bandwidthproblem. Using numerical simulation software to draw image gave a verygood theoretical explanation.2. Broadening of2-D photonic crystal lattice, using fourier interferenceto make a two-dimensional photonic crystal lattice, then measure thediffraction of light power method, use diffraction optical power value, drawthe photonic crystal lattice of the diffraction efficiency of band gap, found bychanging the amplitude mask, success in the broadening of the photoniccrystal band gap.3. Study square two-dimensional photonic crystal band gap properties inall directions，draw the photonic crystal lattice of the diffraction efficiency ofband gap，found the quartet of two-dimensional photonic crystal band gapbasic is the same in all directions，square lattice of this feature can be used tomake large band gap of two dimensional photonic crystal lattice, have certainapplication value.4. Study of defect mode, used cross phase method to make the defectstates of photonic lattice，measured bragg band gap of photonic crystal latticedefect states. Photonic crystal band gap appeared allowed band after theintroduction of line defects. This feature in the photonic crystal fiber, cavityand photonic crystal waveguide has broad application prospects.