Patent ID: 6226425
Filing Date: 2001-05-01
Classification: H04J

Abstract:
A multiplexer for a wavelength division multiplexed optical communication system, comprising:an optical circulator including at least a first, second, third and fourth circulator ports;an optical fiber with a first optical transmission path coupled to the first circulator port of the optical circulator and carrying a wavelength division multiplexed optical signal including signals .lambda..sub.1 -.lambda..sub.n and at least one signal .lambda..sub.1 to be dropped by the multiplexer;a second optical transmission path in optical communication with the second circulator port;a first detector/filter coupled to the second optical transmission path, the first detector/filter detecting the .lambda..sub.1 signal and passing a portion of the .lambda..sub.1 signal, and reflecting a first residual .lambda..sub.1 signal and signals .lambda..sub.2 -.lambda..sub.n to the optical circulator;a third optical transmission path in optical communication with the third circulator port and transmitting the signals .lambda..sub.2 -.lambda..sub.n received from the optical circulator;a fourth optical transmission path in optical communication with the fourth optical circulator port, the fourth optical transmission path being positioned after the second optical transmission path and before the third optical transmission path; anda first optoelectronic device coupled to the fourth optical transmission path.