Passive networks that fit like a glove!


11.08.22

You’ve heard about Passive Networking. It saves money and provides options for scaling your network as your needs grow. This is true even for off-the-shelf filters.  But to make your network all that it can be you’ll need functions, features, and options that are designed specifically to meet your needs.  It’s the difference between buying off the rack and getting a custom-tailored suit; only one is a perfect fit.

Up To Speed Fast on Passive networks.

Passive network filters manipulate the light that’s on a fiber.  Filters have a limited set of actions; splitting, combining, adding, and subtracting. These operations work together to create an astounding number of functions and features.

A mux/demux can take several different wavelengths from CWDM or DWDM transceivers and combine them to travel over a single fiber where a filter on the far side breaks them apart again. 

Or, several signals are combined at a source and individual channels are pulled out at different points on a fiber using what are called Optical Add-Drop Multiplexers (OADM) filters.

Or, you can tap a signal to send it to multiple destinations with a splitter.  All these filters add capacity and versatility to your fiber network.

A simple filter that combines basic Add/Drop and Splitter functions

Course Wavelength Division Multiplexing (CWDM) has 18 channels (though only 16 are commonly used) which range in frequency from 1271nm to 1611nm with 20nm increments.  These wavelengths cover the ranges known as the

O-Band “Original” (1260-1360nm)

E-Band “Extended” (1360-1460nm)

S-Band “Short Wavelength” (1460-1530nm)

C-Band “Conventional” (1530-1565nm)

L-Band “Long” (1565-1625nm)

(There is also a U-Band “Ultra-Long Wavelength” (1625-1675), but that’s used predominantly for network monitoring functions.)

Impurities and characteristics of a fiber have it interfering with light with different levels of attenuation depending on the wavelength.  Light in the 1380-1410 range is particularly hard it as you can see in the diagram and that spike is called the “water peak”.  Advances in fiber manufacturing have mostly relegated this problem to the past but, given the amount of old fiber in the field, the channels that use this range are often skipped.
 
 
You CAN get there from here!
Most networks grow past their starting architecture and the challenge of upgrading your network can induce panic. But don’t worry, there are filters for that.  
There are options for special ports intended to carry 1310nm or 1550nm graywave signals alongside the WDM channels, which means that the network upgrade and be done in minutes by just adding your filters in line with your existing optic. The Integra Optics PC1C-5C347-NN4V1 is a 5-channel CWDM filter with extended 1310 and 1550 bands that was developed to allow the use of both existing graywave optic types.

Other options include:
·        CWDM filters with ports to allow for DWDM expansion in the future
·        DWDM filters designed to plug into CWDM 1530 and 1550 ports
·        CWDM and DWDM filters designed to operate over a single fiber
·        Monitoring port options so that OSAs can check signal strengths without interrupting traffic
·        OTDR ports that allow spans to be characterized without impacting or being impacted by operating signals on the span
·        Express ports that allow additional channel groups through with cascaded filters
 
The Art of Design
Integra Optics knows that taking these optional features and putting them together to make the perfect filters for your application can be daunting, which is why we have experts to help.   Integra Optics has conventional channel sets with vanilla options, sure, but we excel at listening to your needs, adding our design experience, and delivering solutions that will provide the best savings in deployment costs and best performance.

Offering passive filters sales and support, fiber jumpers, cleaning supplies, and test equipment, Integra Optics is your partner in performance and reliability.  Not least, we’ve got the transceivers to make it all work.  The graywaves, the CWDM, the DWDM, the Bidis, and the tunables. In all the form factors and for all the platforms in your network.