The present invention relates to the technical field of
optical fiber measurement and specifically relates to a
noise suppression device and a
noise suppression method for the distributed polarization
crosstalk measurement of an optical
polarizer. The
noise suppression device for the distributed polarization
crosstalk measurement of the optical
polarizer comprises a
broadband optical source, a
polarizer, a first
fiber-optic rotary connector, a second
fiber-optic rotary connector, a to-be-detected
optical fiber device, an
optical path correlator, and a polarization
crosstalk detecting and
signal recording device. According to the technical scheme of the invention, the transmission light and the coupled light are thoroughly separated by means of a
polarization beam splitter, so that the noise influence on the interference beat length can be avoided. On the basis of the thermal noise of a
control circuit, the transmission light is attenuated by an attenuator, and the coupled light is enabled to be main detecting light. In this way, the
shot noise becomes the main noise for limiting the
signal noise ratio of the
system. Based on the above method, the parameters of the device are adjusted to be appropriate. In this way, on the premise that the
dynamic range of the
system is kept unchanged, the
signal noise ratio of the
system is improved by 20 to 40 dB. Therefore, the measurement sensitivity is effectively increased.