Patent ID: 7190850

Claim:
A PMD emulator comprising: an input-side optical fiber for receiving light to be measured; an output-side optical fiber for outputting the light to be measured; a first polarization rotating portion including M DGD sections (M is an integer equal to or more than 2) and (M−1) polarization rotators alternatively concatenated with M DGD sections, one DGD section being arranged at each end of said first polarization rotating portion; a second polarization rotating portion including N DGD sections (N is an integer equal to or more than 2) and (N−1) polarization rotators alternatively concatenated with N DGD sections, one DGD section being arranged at each end of said second polarization rotating portion; and an arbitrary-arbitrary polarization controller for changing any state of polarization into any other state of polarization; wherein said input-side optical fiber is connected to a DGD section at an input side of said first polarization rotating portion, a DGD section at an output side of said first polarization rotating portion being connected to a connecting portion at an input side of said arbitrary-arbitrary polarization controller, a connecting portion at an output side of said arbitrary-arbitrary polarization controller being connected to a DGD section at an input side of said second rotating portion, and a DGD section at an output side of said second polarization rotating portion being connected to said output-side optical fiber.