Polarizing function element, optical isolator, laser diode module and method of producing polarizing function element

摘要

This invention has the polarizing function of polarizing an input beam and a non-reflecting function of suppressing reflection of the input beam, wherein at least one side of a light-transmissive substrate 1 has a polarizing portion 4 with a striped structure formed by multiple alternating light-transmissive dielectric layers 2 a, 2 b . . . and metallic film layers 3 a, 3 b . . . . Its characteristics are improved if the metallic film layers are very thin and flat, with a target thickness in the range from 5 to 20 nm and variation of film thickness within the range of ±10%.