To provide a variable type polarization maintaining optical signal delay circuit which is inexpensive compared with a conventional one, is capable of realizing miniaturization and is capable of easily changing a delay time.
In the polarization maintaining optical signal delay circuit in which at least two or more loops 6A, 6B and 6C consisting of a polarization maintaining optical fiber are provided with two sets of input/output ports and are connected via optical switches 1B and 1C, a first stage loop 6A is provided with two sets of input/output ports and is composed by connecting between a set of input/output port of a polarization optical switch 1A having different optical paths depending on the kind of polarization with the polarization maintaining optical fiber, and moreover a half wavelength plate 7 is inserted into the loop 6A.
OURA KOJI
ASANO KENICHIRO
HOSOYA HIDEYUKI
