Townsend P D, Poustie A J, Hardman P J, Blow K J
Opt Lett. 1996 Mar 1;21(5):333-5. doi: 10.1364/ol.21.000333.
The refractive-index modulation generated in optical fibers by electrostriction-induced acoustic waves is investigated directly by a pump-probe measurement technique in a 1-km-long fiber Sagnac-loop interferometer. Pump pulses propagating unidirectionally around the loop generate transverse acoustic waves that produce a time-dependent relative phase shift for the probe pulses. The consequent interferometer transmission changes are used as a measure of the acoustic interaction. The acoustic impulse response function of the fiber is measured by use of short optical pulses with a 1-MHz repetition rate. The response consists of a series of peaks separated by ~21 ns with a maximum value of refractive-index modulation of -1.1 x 10(-11) generated by the 230-pJ pump pulses. At a higher pulse repetition rate of 100 MHz additional temporal structure is generated in the 0-5-ns period after the pump pulse, leading to a response similar to that observed in longrange soliton interaction.
在一个1公里长的光纤萨格纳克环干涉仪中，通过泵浦-探测测量技术直接研究了由电致伸缩诱导声波在光纤中产生的折射率调制。沿环单向传播的泵浦脉冲产生横向声波，这些声波会为探测脉冲产生随时间变化的相对相移。由此产生的干涉仪传输变化被用作声学相互作用的一种度量。光纤的声脉冲响应函数通过使用重复频率为1 MHz的短光脉冲来测量。该响应由一系列间隔约21 ns的峰值组成，由230 pJ的泵浦脉冲产生的折射率调制最大值为 -1.1×10⁻¹¹。在100 MHz的更高脉冲重复频率下，在泵浦脉冲后的0 - 5 ns时间段内会产生额外的时间结构，导致产生类似于在长程孤子相互作用中观察到的响应。
