Recently, Professor Feng Ting’s team from the School of Intelligent Sensing and Optoelectronic Engineering, NEU at Qinhuangdao, published a research paper titled “Low‑Noise and Broadband Random Fiber Laser Enabled by Seed Injection for Advanced Distributed Raman Amplification” in the top‑tier international optical journal Laser & Photonics Reviews (CAS Q1 TOP Journal, impact factor: 9.7).
Figure: Structure and Time‑Domain Characteristics of the Low‑Noise and Broadband Random Fiber Laser Enabled by Seed Injection
The paper elucidates how backward broadband seed injection suppresses noise transfer in cascaded Raman processes and broadens the spectrum of a random laser. By injecting broadband incoherent seed laser backward into the transmission fiber, the higher-order random Raman laser propagates predominantly in the direction opposite to that of the lower-order Stokes light. This backward Raman interaction averages out pump-intensity fluctuations. Meanwhile, the phase- and power-averaging effects of the broadband spectrum reduce the relative intensity noise of the higher-order random laser and broaden its output spectrum.
This research provides a new method for realizing high‑power, broadband and low‑noise random fiber lasers, and offers important technical support for higher‑order distributed Raman amplification in systems such as long‑haul optical‑fiber communication and distributed optical‑fiber sensing. The proposed random laser pumping scheme can be further extended to bidirectional pumping and hybrid distributed Raman amplification architectures. It has the potential to increase the transmission reach and detection range of optical-fiber communication and sensing systems, offering a new route to developing high-performance optical amplification and sensing systems.
