High Optical Feedback Tolerance of a Detuned DBR Laser for 10-Gbps Isolator-Free Operation
High Optical Feedback Tolerance of a Detuned DBR Laser for 10-Gbps Isolator-Free Operation
复制标题
失谐 DBR 激光器的高光学反馈容差，可实现 10 Gbps 无隔离器操作
DOI：
10.3390/photonics10010038
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发表时间：
2022
期刊：
影响因子：
2.4
通讯作者：
Lingjuan Zhao
中科院分区：
文献类型：
--
作者：
Qiulu Yang;D. Lu;Yiming He;Daibing Zhou;Lingjuan Zhao
对分布布拉格反射器（DBR）激光器的光反馈容限（OFT）进行了实验研究。通过测量DBR激光器的相对强度噪声（RIN）和误码率（BER），研究了DBR激光器在光反馈下的静态和调制性能。结果表明，DBR激光器的OFT与其峰值波长相对于布拉格波长的失谐量密切相关。当DBR激光器相对于布拉格波长发生红失谐时，在连续波（CW）和直接调制（DM）状态下都表现出对光反馈的高容忍度。在CW状态下，当反馈电平为−9 dB时，光反馈引起的过量RIN被很好地抑制到−140 dB/Hz。在10 Gbps直接调制状态下，对于背靠背传输的情况，在-15 dB和-9 dB的反馈电平下分别获得了低于1 × 10−9和3 × 10−7的误码率（BER）。经过20 km的光纤传输，在反馈电平为-15 dB的情况下，误码率仍保持在1 × 10−7以下，功率代价小于1 dB。
The optical feedback tolerance (OFT) of a distributed Bragg reflector (DBR) laser was investigated experimentally. The static and modulation performance of the DBR laser under optical feedback was examined by evaluating its relative intensity noise (RIN) and bit error rate (BER). It is shown that the OFT of the DBR laser is closely related to its peak wavelength detuning relative to the Bragg wavelength. A high tolerance to optical feedback was demonstrated, both in the continuous wave (CW) and the direct modulation (DM) states, when the DBR laser was red-detuned relative to the Bragg wavelength. The excess RIN induced by optical feedback was well suppressed to a level of −140 dB/Hz at a feedback level of −9 dB in the CW state. In a 10 Gbps direct modulation state, bit error rates (BER) below 1 × 10−9 and 3 × 10−7 were obtained under a feedback level of −15 dB and −9 dB, respectively, for the case of back-to-back transmission. After 20 km fiber transmission, the BER still maintained below 1 × 10−7 under a feedback level of −15 dB, with a power penalty of less than 1 dB.