An optical launching device for optical direct amplifier.

摘要

A high power pump light source for optical direct amplifier using the stimulated Raman effect is obtained by using a plurality of semiconductor lasers (11, 12) each of which provides low output power. More than two beams of the same wavelength generated by semiconductor lasers are combined (polarization multiplex) by using a polarization prism (15) block (15), which provides sufficient high power pump light for the stimulated Raman effect amplifier. The output of said polarization prism block is wavelength division multiplexed with signal light to be amplified by using an interference filter block (16), output of which is applied to a transmission optical fiber (13d) in which amplification of said signal light is effected.