Bidirectional optical fiber amplifier

Abstract

Abstract PURPOSE:To suppress reflected light and to use a light pulse tester by providing an optical circulator which has rare-earth added optical fibers and four ports as input and output terminals for light. CONSTITUTION:When signal light is propagated from a connection point 8a to 8b, the light is multiplexed by an optical coupler 3a with excitation light and inputted to a 1st rare-earth added optical fiber 1a to excite the fiber, so that the signal light is amplified by this fiber 1a. Then the light is inputted to a port 2-A of the optical circulator 2 together with naturally emitted light and passed through an optical fiber 5 from a port 2-B, and only the signal light is outputted from a connection point 8b. The signal light is never reflected to return to the port 2-A because of unidirectional constitution. This reflected light, however, is propagated from 2-B in the order of 2-C, 2-D, and 2-A. At this time, when no exiting light is made incident from an excitation light source 4b, an optical fiber 1b operates as an optical attenuator for the reflected light propagated in a direction B, so the reflected light is not outputted to a connection point 8a. The signal light propagated in the direction B is inputted from the port 2-B, multiplexed with the excitation light from the light source 4b, and outputted to the port 2-A. Then the light is amplified by the fiber 1a and outputted to the connection point 8a.

Inventors

• 👤 Yoshiaki Sato
• 👤 良明 佐藤
• 👤 Shigeto Nishi
• 👤 成人 西
• 👤 Koichi Aoyama
• 👤 青山　耕一

Bibliographic Details