PRODUCTION OF FUNCTION PART OF POLARIZATION INDEPENDENT TYPE OPTICAL ISOLATOR

摘要

PROBLEM TO BE SOLVED: To prevent the sepn. of a forward direction beam which occurs when a function part is inclined and installed in order to prevent multiple reflection by adjusting the thickness of a double refractive parallel flat plate so as to make the sepn. distance of the exit positions between an ordinary ray and extraordinary ray substantially zero. ;SOLUTION: The length (thickness) of the arbitrary double refractive parallel flat plate is adjusted so as to cancel the sepn. between the ordinary ray and extraordinary ray in a formed direction induced by the inclined arrangement of the polarization independent type optical isolator function part. Namely, the polarization independent type optical isolator which prevents the sepn. of the forward direction beam by changing the length (thickness) of the arbitrary double refractive parallel flat plate by the value determined by the angle and direction of the inclined arrangement at the time of arranging this function part (nonreciprocal part) obliquely with the optical axis is possible. The polarization independent type optical isolator function part is so improved that the forward direction transmitted light is focused at one point when the function part is installed to incline with the optical axial line, by which the loss fluctuation (PDL) by the polarization state of incident light is suppressed to a smaller level.;COPYRIGHT: (C)1999,JPO