Design Of Automatic Grating Diffraction Efficiency Testing Instrument

Diffraction grating as a unit optical component, in its200years of history, hasplayed the role of play a decisive role. Its application can say covering variousagricultural, industrial, life etc., as professor George.R.Harrison said.” It is difficult tofind another like a diffraction grating that too many scientific fields to create a simpledevice are more important information. Physicists, astronomers, chemists, biologists,metallurgist and use it as a precision tool very excellent daily, as atomic species todetermine air detector characteristics and planetary bodies in existence, study ofatomic and molecular structure, and get all sorts of information contributes to thedevelopment of modern science”[1]. And the diffraction efficiency is one of the mostimportant performance index gratings. Before the development of instrument, thediffraction efficiency of the gratings is usually line spectrum method and manualequipment detection. The test data is not enough to reflect the performance ofdiffraction grating. In this paper, the design of a fully automatic continuous spectraldiffraction efficiency testing instrument, the success of this instrument, to improve thespeed and accuracy of grating test, Reduce the working intensity of operators and thedifficulty of operation.In this paper, we first introduce the basic principle of diffraction gratings anddiffraction efficiency, by comparing the three kinds of basic methods of diffractionefficiency test, designed an automatic grating diffraction efficiency tester based on theconcept of continuous spectrum method.Design of automatic test instrument of diffraction efficiency of grating covers:optical design and optimization design, precision machinery, motor control system,weak signal amplifier, analog-to-digital conversion, software development and so ontechnical means. In this paper, firstly introduces the optical design and mechanicaldesign of the part of the process.Then, electronics design part discusses in detail:1) the overall design ofelectronics, draw out the whole block diagram of electric control system of motorcontrol system;2) lists the motor type, main parameters of motor drive;3) acquisitioncard system includes, sensor selection and the main parameters, the main parametersof tlc2543chip;4) design method of high voltage automatic switching aphotomultiplier.In the software design part:1) select software development platform;2) hasdeveloped a set of communication protocol;3) grating automatic position adjustmentstrategy;4) drawing the main flow chart of software system;5) lists several key code. Including: automatic adjustment of the position of the grating, photomultiplier tubeautomatic transmission;6) show the user interface of software.Finally, the instrument was tested, including five parts: the diffraction efficiencymeasurement of continuous spectrum, wavelength pass band width, stability ofinstrument accuracy, repeatability of measurement accuracy, measurement speed,given all the test methods and test data. The test results show that, the instrumentconforms to the design requirement satisfies the user the use of standard.This instrument is successful, improve the diffraction efficiency of grating testinglevel of domestic, in favor of grating quality control, and enhance the internationalcompetitiveness of Chinese grating.This instrument is successful, because the test level of grating diffractionefficiency increased, additional, enhance the international competitiveness of Chinesegrating.