| 摘要 |
PURPOSE: To reduce the number of stages of a light wavelength conversion element by setting the wavelength multiplicity of a light signal even and dividing the signal and making the group on one side flow together with the one on the other side after applying wavelength conversion. CONSTITUTION: It is assumed that a plurality of channels with an even number of wavelength multiplicity is formed, and the light signals to a to h in an input light signal Li are arranged at equal wavelength interval in wavelength sequence λ1 -λ8 . The input light Li is divided into L1 and L2 by a branch part 20, and L1 is inputted to a wavelength conversion element 30, and L2 is sent out to a confluent part 50 as it is via a transmission line. The wavelength conversion element 30 sends the light signal L3 in which the order of wavelength is converted by mirror-symmetrically inverting to the confluent part 50, and the light signals a to h in which the light signal L3 whose wavelength is converted by joining selectively with the light signal L2 are obtained. At this time, assuming a degree of multistage as N, it is N=2<n> , and one time of wavelength conversion is executed by the light wavelength conversion element of one stage, and the available combination of wavelength conversion when plural stages are connected in series, i.e., the maximum number of stages connectable the light wavelength converter element is set at [(2log2 )-1]. |
