Overview

The FiberPlex WDP8 is a rack-mountable passive 8 channel coarse wavelength division multiplexer. Unlike the similar FiberPlex products in the WDM series, this unit is passive and all connected fiber optic modules must be externally selected to specific wavelengths. Being a passive unit, the WDP16 requires no external power and occupies a smaller 1U rack space. Fiber optic inputs and outputs are connected via singlemode duplex LC/PC mating sleeves in the rear of the unit.

WDM Theory of Operation

Infrared light has a frequency of approximately 400 Terahertz (400,000 Gigahertz). That is about 125,000 times higher than the data rate of a typical 3 Gigabit SFP, which means a large proportion of the bandwidth of a fiber optic cable is wasted. The current state of the art does not allow utilizing all of that bandwidth, but we can recover some of it by a technique called “Coarse Wave Division Multiplexing,” or “CWDM.”

Essentially, it is the simple technique modulating light on different frequencies in that 400 Terahertz bandwidth. This is done through a series of optical filters and combiners, along with lasers and photodiodes tuned to a particular infrared center frequency. Historically, however, optics are referred to, not by their frequency, but by their wavelength, which is the speed of light divided by the frequency expressed in nanometers (nm).

Due to its passive nature, the WDP8 require the user to match the external equipment with the proper wavelength channel. There are several advantages of the WDP16 passive CWDM versus FiberPlex’ active WDM8 system depending on application. The WDM8 will only accept digital signals via externally installed SFP modules. While this works for many applications, signals such as RF optical are analog in nature and cannot be used with SFP modules. These analog signals will work perfectly with the WDP8. In addition, since the WDP8 is passive, there is no power consumption or heat issues to deal with. Power supplies in electronic equipment are notoriously a point of failure. Since the WDP8 has no power supplies, they are inherently more reliable.

Differences between WDP16, WDP8A and WDP8B

The functional and physical characteristics of the WDP16, WDP8A and WDP8B are largely identical. The single differentiator is the number of Wave Division channels and the associated internal wavelengths that are supported. The chassis dimensions remain identical. The WDP16 supports all of the 16 standard CWDM wavelengths of 1311-1611 nm, whereas the WDP8 units support only 8 of those channels, so the installation can be scaled to the appropriate size. The WDP8A supports the upper 8 wavelengths 1471-1611 nm and the WDP8B supports the lower 8 wavelengths 1311-1451nm.

When only 8 channel point to point functionality is desired, the WDP8A should be the model of choice.

Typical Applications

 Campus Solution

Survelance Application