Excitation light source for raman amplification, raman amplifier, and optical transmission system

摘要

An excitation light source, for Raman amplification, includes a polarization beam splitter (PBS) for splitting a laser beam from an excitation laser into two polarization components, and a polarization beam combiner (PBC) for combining the two polarization components, and a time difference generator provided between PBS and PBC. The time difference generator generates a difference in propagation time between the two polarization components.

主权项

1. An excitation light source for Raman amplification comprising:
a laser beam output unit configured to output laser beam; a polarization beam splitter configured to split the laser beam into two polarization components; a polarization beam combiner configured to combine the two polarization components; and a time difference generator, provided between the polarization beam splitter and the polarization beam combiner, configured to generate a difference in propagation time between the two polarization components, wherein
an optical path is configured to be formed between the polarization beam splitter and the polarization beam combiner is formed by a spatial optical system,the time difference generator is configured to generate the difference in propagation time between the two polarization components by making optical lengths of the two polarization components to differ from each other,the time difference generator further includes an optical glass or an optical crystal provided in an optical path of at least one of the two polarization components, and a refractive-index control unit for varying the refractive index of the optical glass or the optical crystal.