Optical Multiplexers / Demultiplexers for Dense Wave Division Multiplex Applications

Synchronous Dense Wave Division Multiplexer/Demultiplexer (Mux/Demux) products are designed for operation in systems which utilize 1550 nm laser transmitters with output wavelengths based on the ITU grid frequency plan. Unlike simple two wavelength (1310 nm and 1550 nm) wave division multiplex systems, Dense Wave Division Multiplexing (DWDM) requires a precision optical device to assure more accurate combining of optical wavelengths. The ITU grid frequency plan arranges laser output wavelengths with separations of 0.8 nm for 100 GHz spacing and 1.6 nm for 200 GHz spacing. Synchronous DWDM units are designed and tested to meet these difficult specifications. The Mux/Demux combinations match the transmitter wavelengths to assure maximum performance with minimum crosstalk. The units are temperature stabilized and have a wavelength accuracy of ±0.1 nm.

While it is possible in some applications to use a standard balanced optical coupler for multiplexing, most optical couplers have excessive loss, requiring greater use of optical amplifiers to provide sufficient signal levels. A typical 8 port balanced combiner has an optical insertion loss of 9.5 to 10.0 dB per leg. A Synchronous DWDM- 8 wavelength multiplexer will have a typical optical insertion loss of less than 6 dB per wavelength. All of the Synchronous DWDM multiplexers have the lowest possible insertion loss to minimize amplifier requirements.

Synchronous Mux/Demux products are available in a number of groupings to allow the best match to the operating system. Standard units are available for 2, 4, 8 or 16 wavelength multiplexing. The most common units are 8 or 16 wavelength. These units are designed in a stand alone, self powered unit. System information is displayed on the unit, providing simple set up and operation. The ITU-OMUX-8 unit has 9 connectors on the front panel. For multiplexing, there are 8 inputs and one output. For demultiplexing, there is one input and 8 outputs. The ITU-OMUX-16 utilizes a similar chassis and provides 18 connections on the unit. Synchronous units use the latest DWDM technology to assure minimum insertion losses and accurate wavelength combining/decombining to assure the highest isolation between wavelengths.

Synchronous, Inc., 77 Las Colinas Lane, San Jose, CA 95119-1214. Tel: 800-659-6750; Fax: 408-362-4851.