Optical filter

Abstract

Abstract PURPOSE:To select a signal having one arbitrary wavelength from wavelength multiplexed optical signals by providing an optical directional coupler which has first and second ports in the preceding stage and has a port in the succeeding stage and a Bragg optical reflector connected to the port in the succeeding stage of the optical directional coupler. CONSTITUTION:Two ports 4 and 6 in the preceding stage of a 3dB optical fiber coupler 2 are optically connected to an optical input part 12 and an optical output part 14 through fiber type optical isolators 8 and 10, and fiber type optical isolators 8 and 10 allow the optical signal from the optical input part 12 to the port 4 and the optical signal from the optical output part from the port 6 to pass through respectively. A port 16 in the succeeding stage is optically connected to a fiber type Bragg reflector 20, and the other port 18 is optically connected to an optical output part 22. The fiber type Bragg reflector 20 is provided with an optical waveguide having a prescribed refraction index (n) and a diffraction grating having a prescribed pitch LAMBDA, and these refractive index (n) and the pitch LAMBDA are effectively controlled. Thus, two wavelength components are efficiently selected.

Inventors

• 👤 Hiroyuki Nobuhara
• 👤 裕之 延原

Bibliographic Details