Windows play an important part in our lives, as shown in popular expressions such as a window of time, maintenance window, window shopping or a window of opportunity.
Optical Transmission Windows (or Wavelengths) are important as well. The first window of note is in the 800nm (780 and 850) range and uses LEDs for the light source. Because of the inherent weaknesses of distance and bit rate, LED sources are replaced by lasers as they moved up the optical spectrum to the second and third low-loss optical transmission windows of 1310nm and 1550nm. In-between these “usable” bands are areas of high loss due to absorption. These windows are affected negatively by the miniscule water vapor in the glass. Thus, “water peak” refers to high loss peaks in those bands. Humans are pretty clever and through scientific research cable manufacturers figured out a way to reduce the water peak problem. Low Water Peak (LWP) and Zero Water Peak (ZWP) glass can reduce and eliminate these water vapor loss issues and open up the E-band window. Additional wavelength windows are used in the 1490nm and 1625nm ranges.
We identify those fiber-optic sweet spots and exploit their characteristics of transmission distance and bit rate.
As we throttle up bit rates using Time-Division Multiplexing (TDM) in each of these windows and “fill them up,” we seek to use additional windows (Wavelength Division Multiplexer or WDM) to quench our thirst for increasingly more bandwidth.
Clearfield® offers wide bandwidth, Coarse Wavelength Division Multiplexing (CWDM) and Dense Wavelength Division Multiplexing (DWDM) passive optical solutions. We can package them in any standard industry form (LGX, OSP, Cassette or Pizza Box) or use custom packaging that is limited only by your imagination.
If you have any questions, reach out to Clearfield. We’re happy to open a window to new fiber optics adventures.
By Jim Pilgrim
Jim Pilgrim has over 40 years of experience in telecommunications with Northwestern Bell/US West, Fujitsu and Clearfield. His work experience includes Central Office switching, fiber-optic transport and application/field support. He currently works as an application engineer at Clearfield, with FOA certification as a Certified Fiber Optic Technician (CFOT). He helps engineering consultants and customers understand how best to use Clearfield products when they are designing fiber networks.