Experimental results on effective two-wave mixing (TWM) via dynamic population gratings in saturable erbium doped fibers (EDFs) at liquid nitrogen temperature (77 K) are reported. It is shown that formation of the spectral holes (SHs) by the recording coherent waves in the wavelength region 1500–1540 nm results in a complex dynamics of the transient TWM response. In addition to conventional slow, even-type response due to amplitude grating formation via spectrally uniform EDF absorption saturation we also observed a dominating contribution due to SH formation. In particular, at the recording wavelength 1527 nm the relaxation time of the SH contribution to the TWM process was significantly shorter (< 4.7 ms) and with the effective recording power ∼4 times lower than that for conventional EDF population grating.

中文翻译：

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掺hole光纤中的两波混合并在77K处燃烧光谱孔

报道了在液氮温度（77 K）下，通过动态填充光栅在饱和掺杂纤维（EDF）中进行有效两波混合（TWM）的实验结果。结果表明，记录的相干波在1500-1540 nm波长区域内形成光谱孔（SHs），导致瞬态TWM响应的复杂动力学。除了传统的慢速，偶数型响应（由于振幅光栅通过频谱均匀的EDF吸收饱和而形成）之外，我们还观察到了由于SH形成而起的主要作用。特别是，在记录波长1527 nm时，SH对TWM过程的弛豫时间显着缩短（<4.7 ms），有效记录功率约是传统EDF种群光栅的4倍。