The invention provides an all-
fiber testing device for testing the polarization
crosstalk of an optical device. The all-
fiber testing device comprises a wide-
spectrum light source (501), a
polarizer (511), a to-be-tested polarizing device (522), an
optical path correlator (530), a difference
detector (550) and a photoelectric
signal conversion and
signal recording device (560), wherein the wide-
spectrum light source (501) is connected with the to-be-tested
optical fiber device (522) through the
polarizer (511) and a first rotary connector (521) and is connected with the
optical path correlator (530) with a polarization
beam splitting Michelson structure through a second rotary connector (523); and the
optical path correlator (530) is connected with the polarization difference
detector (550) through a third rotary connector (541) and is connected with an interference
signal detecting and
processing device (560). The all-
fiber testing device has the advantages of small size, high measurement accuracy, high temperature and vibration stability and the like, so that the all-fiber testing device is widely applied to high-accuracy measurement and analysis of the polarization performance of the optical device.