Table 2 shows the typical PDL measurement capabilities of each method compared to possible performance requirements. The power and PDL ranges shown in this table will be referred to throughout this document. Use this table to decide which measurement method is most appropriate for a specific application.
Table 2. PDL measurement method performance comparison
Among the three methods offered, the Power Meter Method offers the highest single-wavelength PDL measurement accuracy. This method is well suited for general-purpose applications.
The Power Max./Min. Method provides single-wavelength PDL data plus polarization state information about which relative
states of polarization create maximum and minimum power points. These power points can be recreated and device performance adjusted using the assistance of Poincare sphere display and Stokes parameter data.
The Swept-Wavelength Method delivers high-speed measurements of PDL across a specified wavelength span. This method is ideal for wavelength-divisionmultiplexing applications where single-wavelength PDL information is not sufficient.
Note that the PDL Measurement Ranges shown in Table 2 relate to the Measurement Accuracy. PDL values greater than the ranges shown can be measured however measurement accuracy may decrease and measurement time (also known as scan time) will increase.