The Study On The Dispersion Theory, Design, Manufacture, And Efficiency Test Of Diffraction Gratings

In this paper the study on the dispersion theory, design, manufacture techniques, and efficiency test methods of diffraction gratings were made in a deep way. Firstly, concerning the study of basic theory of diffraction gratings, the general equation to the one-dimensional and two-dimensional plane gratings, the complete expression of the angular dispersion, as well as the concept of the first and second kind of angular dispersion were presented, and the inner relation between the two different kinds of angular dispersion of the diffraction gratings was discussed systematically based on the vector diffraction theory. All these theoretical work above mentioned is a complement to the overall theories of diffraction gratings. Secondly, the more accurate expressions that can be used to explain the distortion of the spectral lines or bands and two kinds of dispersion expressions for the plane gratings were described, the result obtained from these expressions shows that the previous formula was approximate and not accurate enough and needed to be given a more general form. Thirdly, in the aspect of design and manufacture of gratings, the general expression of the diffraction efficiency of rectangle gratings were deduced, the analysis to the phenomenon of order-missing of the spectra of the rectangle gratings was made, the complementarity between the longitudinal mismachining tolerance and the transverse mismachining tolerance was firstly found by numerical analysis, moreover, the gratings in the read-and-write head of VCD was obtained based on the design result. Fourthly, concerning the study of the ruled technics to metal gratings, the physical model of the actual ruled gratings was established, the technics of ruled laser gratings and metrological gratings was discussed in detail. The shape of gratings grooves wasobtained by using advanced test methods, which is valuable as a reference to improve the precision of ruled gratings. Fifthly, deep study to the properties, the accurate method of controlling the grating constant, common problems during the process of exposure and development, and special problems of the ion-beam etching technics were made on the holographic gratings. Moreover, the holographic and ion-beam gratings were manufactured. Sixthly, the continuous scanning test principle of diffraction efficiency of plane gratings was expounded, design scheme of auto testing instrument and its merits and demerits were analyzed. A new design scheme of auto testing instrument for gratings efficiency was proposed, which had compact structure, easily acquired precision and was capable of real-time test. Its feasibility analysis was made for actual manufacture.