Optical demultiplexer circuit and demultiplexer device and optical wavelength division multiplex circuit

Abstract

An optical demultiplexer to reduce the number of expensive dispersion compensators when compensating secondary dispersion during demultiplexing. By providing optical circulators, dispersion compensators, and optical filters that reflect specified wavelengths and transmit wavelengths other than the specified wavelengths from among the outputs of the dispersion compensators, and causing specified wavelengths to make round trips of the dispersion compensators, the dispersion volume of the dispersion compensators is reduced.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is based upon and claims priority of Japanese Patent Application No. 11-041494, filed Feb. 19, 1999, the contents being incorporated herein by reference. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates to an optical transmission system employing an optical wavelength division demultiplexing system and, more particularly, the present invention relates to an optical demultiplexer device which performs demultiplexing using a reduced number of dispersion compensators. [0004] 2. Description of the Related Art [0005] Recently, the number of multiplexed wavelengths in an optical wavelength division multiplexing system has increased, from thirty-two (32) wavelengths, to sixty-four (64) wavelengths, to one-hundred twenty-eight (128) wavelengths. Furthermore, transmission signal speeds have increased from 2.5 Gb / s, to 5 Gb / s, to 100 Gb / s, and capacity has increased. [0006] As tran...

AI Technical Summary

Benefits of technology

[0014] It is an object of the present invention to provide a demultiplexer device for demultiplex system which reduces the use of expensive dispersion compensators by half while performing demultiplexing.

Problems solved by technology

As transmission signal speeds of wavelength division multiplexing systems increase, the penalty rate increases for the self-phase modulation caused by the group velocity dispersion (GVD) of the optical fiber that is the transmission path.

However, because the dispersion characteristics of the transmission path are dependent upon wavelength, when the wavelength division multiplexing system is used, as shown in FIG. 11, even if the dispersion value of the central wavelength is set at zero, the dispersion cannot be set for all the wavelengths.

However, as shown in FIG. 10, when a dispersion compensator corresponding to each wavelength is provided, expensive dispersion compensators require the value equivalent to the compensation value.

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