An optical element according to the present invention has a thin film, in which
single-wall carbon nanotubes are laminated, and utilizes a saturable absorption
function of the single-wall carbon nanotubes. Further, in a method for producing
the optical element according to the present invention, the thin film is formed
by spraying, to a body to be coated, a dispersion liquid prepared by dispersing
the single-wall carbon nanotubes in a dispersion medium. Accordingly, a nonlinear
optical element, which can operate in an optical communication wavelength region
and which is extremely inexpensive and efficient, and a method for producing the
optical element can be provided.