Negative Refraction Of Photonic Crystals Abnormal Doppler Effect Experiment

The study of negative refraction materials has important scientific significanceand practical application of benefits in line with the development trend of scientificresearch, which is the cutting-edge topic in the physics. Photonic crystals as the basisfor the future integration of optical materials, optical communications, microwavecommunications, optoelectronic devices, optoelectronic integrations, and nationaldefense areas such as stealth materials, have very broad application prospects, theyhave been classified as strategic research projects in many countries. An internationalcompetition of photonic crystals has attracted much focus.The current study on negative refraction materials is focused on two aspects:One is the research of negative refraction materials, how to design their structures toimprove performance, the objective is to broaden the range of frequency of negativerefraction, to minimize the loss and to explore the new methods of synthesis ofnegative refraction materials; The other is the research of the physical effects ofnegative refraction materials. For the moment, the important progress is being madeand received in the negative refraction effect and in the “super lens” effect whichbrought forward by Pendry. Other areas, the research of the reversed Doppler effectand the reversed Cerenkov effect, and other anomalous effects is very little.In view of this, this article dedicated to the experimental verification of thereversed Doppler effect of negative refraction photonic crystal. Based on thepreparation of the photonic crystal sample and the strict set of the whole experiment,combination of optics, electronics and mechanical knowledge to build an opticalsystem to measure the reversed Doppler effect of negative refraction photonic crystal.The main research contents and important results for the paper are given as follows:We designed the photonic crystal structure in theory, prepared the photoniccrystal samples according to the design, and made a usable experimental photoniccrystal component under the universal microscope. Good performance of thephotonic crystal component is the primary condition for the success of theexperiment.From two different aspects: the Doppler effect and the optical path, the designedexperimental program is theoretically analyzed. Theoretical formula of opticalcurrent and beat frequency about the experiment are obtained, and it is illustrated that the designed experimental program can prove the reversed Doppler effect. Inaddition, the laboratory equipments for the experimental optical systems (opticalsignal and reference light path), scanning control systems and data acquisitionsystems are illustrated. Besides, the overall control procedure design of theexperiment is described. Program design and the careful select of the experimentalequipment made a full preparation for the success of the experiment.The first demonstration of the existence of reversed Doppler effect in photoniccrystal is realized. Verified the normal Doppler effect for the wavelength of632.8nmand10600nm, the experimental result is agree with the theory. The negativerefraction phenomenon at the wavelength of10600nm is verified by the experimentusing refractive of the prism. According to the designed optical structure, it isverified the relative error between experimental results of reversed Doppler effect ofphotonic crystal and the theoretical values can be controlled within10%.