PERFORMANCE EVALUATION DEVICE AND PERFORMANCE EVALUATION METHOD OF WAVEGUIDE TYPE OPTICAL MODULATOR

摘要

PROBLEM TO BE SOLVED: To provide a performance evaluation device and a performance evaluation method which evaluate the performance of a waveguide type optical modulator which does not constitute an MZI alone, more easily than conventional devices and methods.;SOLUTION: Only a propagation mode in a direction along two circles is inputted to a first polarization maintaining fiber 303 via a first polarizer 302. The first polarization maintaining fiber 303 has the direction along two circles inclined at 45° to a substrate of an LN modulator 304 and is optically coupled with one end of an optical waveguide of the LN modulator 304, whereby light is equivalently distributed between the TE mode and the TM mode and is propagated to the optical waveguide of the LN modulator 304. In the LN modulator 304, a refractive index of the optical waveguide is varied with an electro-optic effect (EO effect), and a phase shift is applied to only propagated light in one propagation mode because the EO effect is anisotropic. A second polarization maintaining fiber 305 also has a direction along two circles inclined at 45° and is optically coupled. A second polarizer 306 transmits only one propagation mode in the second polarization maintaining fiber 305.;COPYRIGHT: (C)2012,JPO&INPIT