Photonic downconversion based on optical carrier bidirectional reusing in a phase modulator.
Photonic downconversion based on optical carrier bidirectional reusing in a phase modulator.
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DOI：
10.1364/ol.39.004990
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发表时间：
2014-09
期刊：
影响因子：
3.6
通讯作者：
Tianwei Jiang;Song Yu;Qian Xie;Jian Li;W. Gu
中科院分区：
文献类型：
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作者：
Tianwei Jiang;Song Yu;Qian Xie;Jian Li;W. Gu
提出了一种基于光载波复用的光子下变频方法。在该系统中，相位调制器（PM）被放置在两个窄带光纤布拉格光栅（FBG），这是设计用于反射光载波和传输光边带之间。光载波在PM中在两个方向上被调制，并且不被注入到光电检测器（PD）中。因此，提高了光载波的利用率，并且避免了PD中的功率饱和。因此，可以提高系统增益。此外，在两个FBG的后面还设计了一个2×2的光耦合器和一个平衡PD。由于相位差的巧妙设计，增益进一步增加了一倍，同时可以降低强度噪声。在实验中，29 dB的增益改善测量相比，传统的双串联强度调制器的方法。本底噪声降低了12.1 dB。
We propose a novel photonic downconversion method based on optical carrier reusing. In the proposed system, the phase modulator (PM) is placed between two narrowband fiber Bragg gratings (FBGs), which are designed to reflect the optical carrier and transmit the optical sidebands. The optical carrier is modulated in the PM in two directions and is not injected into the photodetector (PD). Thus, the utilization ratio of the optical carrier is enhanced and the power saturation in the PD is avoided. Consequently, the system gain can be improved. In addition, a 2×2 optical coupler is cooperated with a balanced PD behind these two FBGs. Resulting from the subtle design of the phase difference, gain is furthermore doubled and intensity noise can be reduced simultaneously. In the experiments, 29 dB gain improvement is measured compared with the traditional dual-series intensity modulators method. The noise floor is reduced by 12.1 dB.