scalar expression
1.An accurate expression for the field distribution on Rowland circle is derived based on Hemholtz equation fulfilled by the scalar scattering field.
2.Then we can derive the expression of the scalar order parameter S, and the result is in accordance with the experiment.
3.The effects of the longitudinal and transverse error of grating in the optical pick-up head of VCD,DVD,and CD-ROM during manufacturing on the transmittance and the ratio of intensity between the assistant and reading beam are analysed numerically by using the general expression of diffraction efficiency obtained from the scalar diffraction theory.
