Grating diffraction is a crucial yet challenging subject in college physics.It is difficult for students to form clear physical images because of the complex forms of theoretical derivation and mathematical expression,this leads to unsatisfactory teaching results.The textbooks only discuss the diffraction characteristics when light is incident vertically on a grating,but the diffraction characteristics when parallel light is incident obliquely on a grating have not been thoroughly explored,and research in this field is still limited.This article starts by applying the theory of light diffraction to derive expressions for the light intensity distribution under the condition of oblique incidence of parallel light on both a single slit and a grating.This extends the analysis of single-slit and grating diffraction from normal incidence to the more general case of oblique incidence.Subsequently,utilizing the powerful interactive interface Manipulate within Mathematica software,combined with the Initialization and Limit commands,a systematic simulation of the light intensity distribution for single-slit diffraction and grating diffraction under oblique incidence of parallel light were carried out.This process involved generating plots depicting the relative light intensity distribution for single-slit diffraction,the relative light intensity distribution resulting from multi-slit interference,the relative light intensity distribution of grating diffraction,and the distribution of diffraction fringes.The visualizations provided by this approach allow students to deeply understand that the light intensity distribution in grating diffraction is a result of the combined effects of single-slit diffraction and multi-slit interference.Single-slit diffraction sets the envelope for the light intensity distribution,while multi-slit interference determines the specific brightness variations within the diffraction fringes.This dynamic and visual depiction of the abstract phenomenon of light diffraction aids in establishing a clear physical image and fosters a profound understanding of both single-slit and grating diffraction for students.
grating diffractionsingle-slit diffractionoblique incidence of parallel lightMathematicavisualizationsimulation