Wave Plate Retardation Of Intelligent Measurement Techniques To Study

In the field of Polarization optics and crystal optics, Phase retarders are important optical components that introduce a phase shift between orthogonal and linearly polarized components of light transmitted through them. Fitted with other polarimetric elements, they can realize modifying of light and controlling of polarization states.In fact, nearly all places that in application of polarization technology couldn't be off the Phase retarder. As a result of its special quality, it's widely applied in domains such as photoelastic mechanics, biomedicine and optics precision measurement and so on. Along with the development of optics precision instrument, the laser and the polarized light technology, the request to the wave plate's precision is increasingly high, the wave plate's detector set to be supposed to have the high survey resolution and high survey reproducibility. Phase retardation is one of the extremely important natures to wave plate, will have the direct or indirect influences on optics precision instrument quality, the laser polarization condition and the optical communication effect. Wave plate's phase retardation with wave plate thickness, stress birefraction, ambient temperature and so on many factors related, thus by survey the wave plate's phase retardation to appraise it's quality will be extremely valuable.Refer to some reference literature, we find many wave plate measurement techniques currently have a general character which is requested the wave plate's optical axis satisfies certain angle, this has brought certain difficulty for the wave plate actual use and the survey. At the same time, in the wave plate survey process, mostly the instrument only is pauses in the laboratory instrument condition, in actual survey mainly by manual operation primarily, operation difficult complex, sometimes the survey also only is restricted in some kind of wave plate and has the longer test cycle and lower reproducibility which does not suit the batch examination. Therefore, it is necessary to study has automatically, convenient, quickly and so on the characteristic wave plate precision measuring systems.In order to change this kind of condition, basing on past research, the paper has studied the wave plate phase retardation precision measuring realization method, and has established the wave plate phase retardation automatic measurement system. The paper divides five chapters:In the first chapter introduction, the development history and present research situation of phase retardation's measurement are introduced. The content, purpose and significance of this paper are also recited.The second chapter mainly introduces basic theory of wave plate surveys. Firstly the polarization and the polarized light knowledge are introduced, and four mathematics expression methods for the polarized light are described. Then the elementary knowledge of wave plate is introduced in detail, chiefly includes some essential properties of the unit and compound wave plate. Finally Malus law and the polarized light interference are introduced.The third chapter mainly introduces several kinds of typical phase retardation measurement plan, including: Advanced polarized light interference method, four-step phase shifting method, 1/4 wave plate method (Senamont Method), pair of 1/4 wave plate method (Tardy Method). All these plan's principle, error source and characteristic are discussed.The fourth chapter mainly introduces a new design of intelligent measurement system to measure the phase retardation of wave plates, which consists of the Optic-mechanical parts, the electrical circuits and the computer software. Firstly the survey principle of the measurement system is introduced and schematic diagram is drew, afterwards the path of rays of the adjustment method and the choice of various parts are described in detail, then each function of the main menu in the designed system software are narrated and the survey procedure flow is explained. In the fifth chapter, the experiment test based on the new system is carried on and the test result and the error analysis are given. By using the new measurement system, 1/4 wave plate and 1/2 wave plate are tested separately, and the test data are listed, after that the corresponding analysis and processing to the data are given. The error sources of the system and the method to reduce erroneous are given. The system erroneous main origin in photosource output drifts, various device azimuth error, the influence of polariser extinction ratio and the stray background light influence and so on, moreover, the temperature fluctuation, the air current undulation, the vibration as well as the human factor and so on will all introduce the error. The measurement result indicates that the measurement error rate below 0.5 percent.The innovation of this paper lies in : a novel method is proposed to measure the phase retardation of wave plates, this method effectively avoid needing to determine the optical axis of the wave plate to be tested, moreover the measuring accuracy to be high and has the generality, it can be used to measure many kinds of wave plates; Next, according to the existing condition of the laboratory, an automatic measurement system is designed and established that consists of the Optic-mechanical parts, the electrical circuits and the computer software.