Patent ID: 6711326
Filing Date: 2004-03-23
Classification: G02B

Abstract:
A multi wavelength optical signal module comprising:a coupling portion with an optical signal transmission use optical fiber; a wavelength separation optical device; a photo detector array; and a signal receiving circuit which amplifies signals from the photo detector array and waveshapes the same, wherein the coupling portion and the wavelength separation optical device are connected by a multi mode optical fiber, the wavelength separation optical device includes a spreading angle reducing means which reduces the spreading angle of the incident optical signals from the multi mode optical fiber, a front polarized light conversion means which converts the incident optical signals from the incident portion into linear polarized light, a wavelength separation means in the wavelength separation optical device which separates the optical signals converted into linear polarized light by the front polarized light conversion means and incident therefrom for every wavelength, and a rear polarized light conversion means which passes the optical signals separated by the wavelength separation means before being received by the photo detector array, and wherein the wavelength separation means is a wavelength separation prism including a plurality of wavelength separation filters, and wherein the optical signals separated by the front polarized light conversion means into two optical passages are merged into one optical passage by the rear polarized light conversion mans, and either the front polarized light conversion means or the rear polarized light conversion means is constituted by a polarized light beam splitter and a &lgr;/2 plate.