The invention discloses a device and method for testing polarization
extinction ratio of a polarization-maintaining
fiber coupler based on
resonator technology. One output end and one input end of the polarization-maintaining
fiber coupler are connected to form a fundamental annular
resonator structure; a polarization axis alignment angle error of the polarization-maintaining
fiber coupler is obtained by testing a
resonance curve of an
optical fiber annular
resonator so as to obtain the polarization
extinction ratio of the polarization-maintaining
fiber coupler. The device for testing polarization
extinction ratio of the polarization-maintaining
fiber coupler comprises an
optical fiber laser, a first
isolator, an
optical fiber annular resonator, a second
isolator, a photoelectric detectorand an oscillograph which are connected in order; and the optical fiber annular resonator is arranged on a temperature-controlled panel. For an in separable optical
waveguide resonator of the opticalfiber coupler, the device and method provided by the invention can test the polarization
extinction ratio of the coupler constituting the resonator in non-destructive manner. The invention provides anovel and simple method for testing polarization
extinction ratio of the polarization-maintaining
fiber coupler with important scientific significance and application value.