OPTICAL FIBER TYPE COUPLER AND ITS PRODUCTION

• Main Authors: FURUKAWA KOICHI, SHIMIZU MASANOBU, HASEMI AKIO
• Format: Patent
• Language: English
• Published: 16.02.1996
• Edition: 6
• Subjects: OPTICAL ELEMENTS, SYSTEMS, OR APPARATUS; OPTICS; PHYSICS

PURPOSE:To miniaturize an optical transmission and reception module and to obtain an optical fiber type coupler by forming an optical branching and coupling part so as to have wavelength selectability with emission optical fibers fo three directions. CONSTITUTION:This optical fiber type coupler 1 in which the optical branching and coupling part 3 to which three pieces of the optical fibers 2 stretched by fusing under heating to branch light in three directions are attached, is formed. The optical branching and coupling part 3 described above has the wavelength selectability with the emission optical fibers of three directions. One central piece amoung the emission optical fibers of the three directions allows selective transmission of a wavelength of a lambda1 band and the other two pieces on both sides allow selective transmission of the wavelength of a lambda2 band so as not to allow transmission of the wavelength of the other bands. Namely, the optical fiber type coupler 1 is formed to have a coupling length at which one light signal of the wavelength of the band lambda1 is outputted from an exit port B2 and the light signal of the wavelength of the band lambda2 attains zero when the light signals of the wavelength of the lambda1, lambda2 of the incident light are made incident from the incident port A1. In such a case, the coupler has the coupling length at which the one light signal of the wavelength of the band lambda2 is outputted from the exit ports B1, B2 and the light signal of the wavelength of the band lambda1 becomes zero.