Physical Principle Of The Fourier Model Method And Its Guidance In Grating Fabrication

As an important optical device, the grating has been applied in many fields, such as integration optics, holographic optics, and developed rapidly. The practices of the grating applying push the development of the grating vector theory. At the same time, the vector theory of the grating also guides the fabrication and applying of the grating.Fourier Model Method is an important part of the vector theory of the grating. It appeared in 1980s. After the development of several decades of years, it has become the most popular method in the vector theory of the grating. Firstly, the physical principle of the Fourier Model Method is analized and the steps of it are expounded in the paper. Secondly, the physical principle of the inverse rule and the RTCM are researched. Due to there is a little people who refers to physical principle of the inverse rule and the inverse rule is very useful to increase the computing convergence, physical principle of the inverse rule is debated primarily and practical example is applied to analyze it. What we do deepens the comprehension of Fourier Model Method, inverse rule and RTCM, and does good to expand their applied fields.Thirdly, Fourier Model Method is applied to analyze the influence to diffractive efficiency of volume phase holographic grating caused by surface undulation. The diffractive property of compound grating is theoretically analyzed and a program is worked out to compute it. The result is that the effect of diffractive efficiency caused by surface undulation is the biggest one in those influences respectively caused by surface undulation, film thickness and refractive index modulating. Furthermore, the paper offers the error limited of these parameters and they are good to guide practical fabrication of the volume phase holographic grating.At last, Fourier Model Method is applied to analyze which kind of grating is the best choice to receive the biggest diffraction efficiency of+ 1 diffractive order in the paper. The paper studies the refraction index sine modulation grating, sine: relief grating, rectangle relief grating and triangle relief grating and compares their error limited of main parameters. We find that the refraction index sine modulation grating is the best choice to get the biggest diffraction efficiency of +1 diffractive order. Moreover, the paper studies the error limited of those gratings, which bring references to practical fabrication.