With the introduction of wavelength division multiplexing and dense wavelength division multiplexing, equipment manufactures have sought to reduce design tradeoffs and costs while maintaining or increasing their product performance. With the need to reduce if not eliminate optical losses and create the all light path from source to destination, equipment manufactures are addressing the concerns of component manufactures to provide increased performance to support configurable designs for 100, 50, and eventually 12.5GHz. One of the most reliable, robust, and high performance devices is the low polarization dependent loss (LPDL) diffraction grating used to disperse wavelengths for channel blocking, add/drop functionality and real time light path reconfigurations.
The networks today have a variety of factors which contribute to the optical loss budget and impact system design cost, facility requirements, maintenance or replacement costs. These factors include first and second order polarization mode dispersion (PMD), polarization dependent loss (PDL), wavelength dependent losses, and chromatic dispersion (CD). Network designers and equipment manufactures have to consider each component capability and its impact to the systems bit error rate (BER). In order to gain an understanding of the advantages of components with low polarization dependency, we will summarize the effects that interplay with these types of components.