Patent ID: 6556743
Filing Date: 2003-04-29
Classification: G02B,H04J,H04Q

Abstract:
An optical signal add and drop apparatus, comprising:a first dual-core ferrule having first and second optical fibers for transmitting at least one optical signal, said optical fibers being disposed to be symmetrical to each other at identical distances from an optical axis; a second dual-core ferrule having third and fourth optical fibers for transmitting at least one optical signal, said optical fibers being disposed to be symmetrical to each other at identical distances from said optical axis; a wavelength division thin film filter for selectively transmitting only an optical signal having a specific wavelength; a first lens for collimating said optical signal inputted thereto from one of said optical fibers of said first dual-core ferrule into a parallel ray and outputting said parallel ray to said wavelength division thin film filter, and for focusing said optical signal inputted thereto from said wavelength division thin film filter and outputting said optical signal to the other optical fiber of said first dual-core ferrule; and a second lens for focusing said optical signal inputted thereto from said wavelength division thin film filter and outputting said optical signal to one of said optical fibers of said second dual-core ferrule, and for collimating said optical signal inputted thereto from the other optical fiber of said second dual-core ferrule into a parallel ray and outputting said parallel ray to said wavelength division thin film filter; wherein said first lens, said wavelength division thin film filter, and said second lens are arranged on said optical axis; the first lens collimates the optical signal inputted through the first optical fiber into a parallel ray and outputs it to said wavelength division thin film filter, and also focuses the optical signal, which is reflected by or passes through said wavelength division thin film filter, and outputs optical signal to be reflected to the second optical fiber or transmitted optical signal to fourth optical fiber through second lens, respectively; and the second lens collimates the optical signal inputted through the third optical fiber into a parallel ray and outputs it to said wavelength division thin film filter, and transmitted optical signal to second optical fiber through first lens, and also focuses the optical signal transmitted thereto from said wavelength division thin film filter through first lens and outputs it to the fourth optical fiber.