A Quadrangular Prism of Self Invisibility

A quadrangular prism of self-invisibility is originally reported in this paper. It is a self-invisible unit, which does not depend on any outer refractive materials or reflective mirrors. Four identical triangular prisms with the lateral faces of mirrors, divided into two groups, are symmetrically placed on two transparent rectangular prisms in a symmetrical way. Two identical rectangular prisms serve as the lateral faces of a quadrangular prism. Two incident beams, parallel to the rectangular prisms, will be reflected by relevant eight mirror faces of all the triangular prisms, in sequence out of the whole system as if the prisms do not exist as long as all the base angles of triangular prisms are adjusted accurately. One of the potential applications will be mentioned briefly.