Wavelength separation optical device and multiple wavelength light transmission module

Abstract

Optical signals of which wavelength is multipled and which are transferred via an optical fiber make incidence to refractive index distributing lens and are converted into substantially parallel light beams, the optical signals converted make incidence into a polarized light conversion element and are separated therein into two light beams and are emitted in a form of two linear polarized light beams of which polarization direction are aligned. The linear polarized light beams are separated by wavelength separation filters and , and make incidence with every two wavelength components either into a polarized light conversion element or into polarized light conversion element and the optical paths for the light beams separated into two by the polarized light conversion element are joined to form one light beam path for every waveform component. The optical signals of the four wavelength components are reflected either by a mirror or by a mirror are converged by such as a hologram lens and, after being reflected by a mirror are detected for every wavelength component by the photo detector array