Patent ID: 9042731
Filing Date: 2015-05-26
Classification: G02B,H04B,H04J

Abstract:
1. An optical module, comprising: a first optical source for outputting a first optical signal having a first wavelength and a polarization vector; a second optical source for outputting a second optical signal having a second wavelength longer than the first wavelength and a polarization vector substantially same with the polarization vector of the first optical source; a third optical source for outputting a third optical signal having a third wavelength longer than the second wavelength and a polarization vector substantially same with the polarization vector of the first optical source and the polarization vector of the second optical source; a wavelength multiplexer for generating a multiplexed optical signal by transmitting one of the first optical signal and the third optical signal and reflecting another of the first optical signal and the third optical signal, the first optical signal and the third optical signal entering the wavelength multiplexer by an angle of 45° as forming a right angle therebetween, the wavelength multiplexer having a cut-off wavelength around the second wavelength; a polarization rotator for rotating the polarization vector of one of the multiplexed optical signal and the second optical signal by substantially 90°; and a polarization multiplexer for multiplexing the second optical signal with the multiplexed optical signal output from the polarization rotator by transmitting one of the multiplexed optical signal and the second optical signal and reflecting another of the multiplexed optical signal and the second optical signal, the second optical signal and the multiplexed optical signal entering the polarization multiplexer by an angle of 45° as forming a right angle therebetween, wherein the wavelength multiplexer has a multi-layered dielectric film formed on a base having a parallelogram plane shape with an acute angle corresponding to a Fresnel refraction angle of the one of the first optical signal and the third optical signal entering the wavelength multiplexer by an incident angle of 45°, the multi-layered dielectric film having a normal making an angle of 45° with respect to the first optical signal and the third optical signal.