Research On The Method For Testing Diffraction Wave-Front

Diffraction grating is one of the most important components which have used in spectroscopic instruments. With the expansion of application fields, diffraction grating have not only been applied in diffraction grating spectrum, but also been widely used in astronomy, quantum optics, integrated optics, biological, optical communications, chemical and metallurgy and other fields.At the same time as the development of science and technology, craft of diffraction grating has reached a new height. The development in characterization technology and research in diffraction grating nature have become priority mission in diffraction grating research. It would be new challenges under the consideration of complex in grating face, increasing of the grating area, improving of grooves characterization density. Therefore, grating quality testing has become an indispensable link.For the detection of diffraction grating, wave aberration measurement of diffraction grating is the important means in evaluating grating quality. Interference, holography and phase comparison have been widely applied. Wave-front defects can be discovered by acquisition and processing of the interference fringes. It will also reflect the lack of grating processing and grating quality,and improve the defects after that. Test in diffraction grating wave-front is mainly used in plane grating currently, as for concave grating diffraction, diffraction efficiency is only parameter can be tested.Wavefront detection methods of concave diffraction grating is discussed in this paper. Wavefront detection methods of concave grating is improved from the plane grating, based on the principle of testing concave grating by the Twyman interferometer. Zero and one class grating fringes can be got by this experiment, Aberration in experiment have been analyzed by the ZEMAX.which has proved feasibility of interfere testing in concave grating.