Wavelength converter

摘要

A wavelength converter which has a simple configuration, which can be controlled easily, operated stably, and used for long-distance mass optical communication, includes a waveguide 5 for causing a change of a non-linear refractive index, a delay interference circuit 6 having two optical paths 62 and 63 of different optical path lengths, and a CW light source 1, wherein a coherent length ( DELTA LC=vg/ DELTA υ where vg is the travelling speed of the CW light in the delay interaction circuit 6), determined by a spectral line width ( DELTA υ) of the CW light output from the CW light source 1, is longer than an optical path difference ( DELTA Ld) between the two optical paths in the delay interference circuit 6 ( DELTA LC> DELTA Ld). <IMAGE>