Abstract: To solve the existing problems in bi-prism interference experiment, the hi-prism sub-wave-front interference principle is analyzed and the bi-prism interference light field is discussed. How to optimize the experi- mental parameters to control the interference light field for the suitable interference fringes to be observed is discussed, so that students can better appreciate the physical ideas and learn the experimental methods. These are helpful to foster the students＇ research capacity and to inspire their innovation sense, and can promote the reform of optics-teaching.

Key words: bi-prism sub-wave-front interference, coherent virtual light source, coherence of the light field, parameter optimization, twice conjugate method