Passive MUX/DeMUX Cables
Two-wavelength, one fiber to two fibers
A MUX/DeMUX cable combines and separates two optical signals on different wavelengths, potentially doubling the data capacity of the installed fiber plant. The single-fiber technology is bi-directional using gray (wide), CWDM, or DWDM wavelengths.
The single MUX end of the cable passes both wavelengths. The two-fiber DeMUX end separates each wavelength signal onto a dedicated fiber strand. Each wavelength passes in only one direction at a time to avoid confusion of signals, but the passive cable allows flow in either direction.
MUX/DeMUX cables are fully passive, and they operate at specific wavelengths. They are transparent to networks and protocols. A pair of cables, as in the example below, attenuates an optical signal by no more than 1.2 dB on either single-mode or multi-mode fiber. Signal reflections are effectively eliminated with angled polished connectors (APC) at the single-fiber MUX interface.
Features
- Environmentally stable
- Wide bandpass for the 1310/1550 nm OADM cable
- CWDM bandpass for the CWDM OADM cable
- DWDM bandpass for the DWDM OADM cable
- Low return loss
- Low cross-talk
- High isolation
- Low polarization dependent
- Optical path epoxy free
Applications
- Theory of Operations
- An Add/Drop module located on a WDM link allows access to individual grid wavelengths without disrupting the other signals. One or more wavelengths may be dropped from the multiplexed signal to receiving devices, and these wavelengths are returned from the same location and multiplexed back into the common trunk. An Epress port passes the wavelengths that were not dropped downstream for access at another location.
- The signal downstream from an Add/Drop module no longer includes the accessed wavelengths, so there is unused bandwidth on these fibers. An identical Add/Drop module may be installed ?back-to-back? with the first to use these wavelengths, or a two-sided module may be used that combines this configuration into a single module for high-density and high-usage applications.
- Passive optical technology is not directional, so light signals may pass in either direction. While an Add module may perform the Drop function simply by sending the signal in the opposite direction, each module is designed to minimize insertion loss to the transmission. Multiple-port Add/Drop modules are therefore designed with matched pairs to balance the insertion loss across the virtual link ports. Balanced insertion losses by wavelength are important when budgeting optical transmission power for a WDM network.
- A bi-directional link may be created with either a pair of one-way\"uni-directional\" fibers or a single two-way ?bi-directional? fiber, each channel using a different wavelength for data in the two directions. Since a data light source may appear at either end of a link, a WDM link may carry a set of wavelengths in each direction to establish multiple bi-directional links over a single fiber."
Application Drawings
Linear Single Fiber Point-to-Multipoint
