Chorum Technologies, a provider of all-optical processors and subsystems, announced that the U.S. Patent and Trademark Office has issued four U.S. patents for Chorum's 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.

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 has a patent portfolio of 27 issued U.S. patents and more than 30 pending patent applications directed to its proprietary optical networking technologies.

About Chorum Technologies:

Chorum Technologies is a provider of all-optical processors and subsystems in the fiber-optics market. For more information, visit www.chorumtech.com.