Chorum Issued Four Patents

RICHARDSON, Texas -- Chorum Technologies, a leading provider of all-optical processors and subsystems, today announced that the U.S. Patent and Trademark Office has issued four U.S. patents for its proprietary optical networking technologies.

U.S. Patent No. 6,175,432, "Multi-Wavelength Cross-Connect Optical Network," is directed to wavelength routing of optical channels in an optical network to support multiplexing and demultiplexing of WDM optical signals. The patent's co-inventors are founders of Chorum Technologies: Dr. Kuang-Yi Wu is vice president of technology and Dr. Jian-Yu (J.Y.) Liu is CTO.

"The '432 patent protects core technologies common to many PolarWave(R) optical Slicer(R) Filter products," said Dr. J.Y. Liu, Chorum Technologies CTO. "In this respect, this is a fundamental patent that transcends our multi-product optical filter offerings."

Chorum Technologies also received three additional patents:

1. U.S. Patent No. 6,208,442, entitled "Programmable Optical Multiplexer," is directed to a device for multiplexing or demultiplexing a WDM optical signal.
2. U.S. Patent No. 6,201,593, entitled "Optical Communication System Having a Liquid Crystal Routing Switch," is directed to a hybrid analog/binary electro-optical modulator using a twisted nematic liquid crystal structure that achieves both a high extinction ratio and a rapid switching speed.
3. A reissued patent, U.S. Patent No. RE37,044, entitled "Tunable Add/Drop Optical Filter," is directed to a tunable add/drop filter that utilizes the unique operational characteristics of a non-reciprocal optical setup and a reciprocal optical setup for wavelength routing, and a tunable filter for wavelength selection.

Chorum Technologies Inc.