  Pulsed pumped four-wave mixing process via $\chi^{(3)}$ non-linearity in
optical fiber can generate optical pulses with continuous variable quantum
correlation. However, pair-wise correlation of the generated pulses in this
system has not been studied. Here we report a time-domain measurement of an
intensity difference squeezed state generated in fiber. With a fast response
differential detection system, we show the generated twin-beam pulses are
pair-wisely correlated, and -3.8 dB (-8.1 dB after detection losses correction)
intensity difference squeezing degree is measured in time-domain. Our result is
benefit for generating multi-mode entangled state by time-division multiplexing
in fiber system.
