EXTINCTION RATIO MEASURING SYSTEM

摘要

PURPOSE:To make possible the easy and exact incidence of light by receiving once a linearly polarized wave or an elliptically polarized wave having a specified polarization state in a constant polarization fiber, connecting the opposite end of the constant polarization fiber and a sample fiber 6 and making incident said wave to the sample fiber. CONSTITUTION:The linearly polarized wave from an LD light source 1 is once received in a single mode fiber 2 and thereafter the light stopped down by a lens 3 and passed through a polarizer 5 is converged by a lens 4. The converged light is received by a polarized wave maintaining pigtail 10. The pigtail 10 of which the fiber length is made half integer times the beat length is used. The opposite end of the pigtail 10 is butted by a connector 11 to the sample fiber 6 and the linearly polarized light is made incident to the fiber 6. The fiber 6 can be set simply by butting the fibers (pigtail 10 and the sample fiber 6) in the above-mentioned manner and therefore the operation is made simple and the easy and exact incidence of the linearly polarized wave is made possible.