Achieving very-low-loss group velocity reduction without electromagnetically induced transparency

A Raman method is studied experimentally for potential optical-wave group velocity reduction in resonant medium. Specifically, we show that the proposed method can achieve significant group velocity reduction comparable to the conventional electromagnetically induced transparency (EIT) method that had been exclusively used to date. In addition, we show that this method has a significantly lower loss compared to the EIT method, and has rich dynamics such as probe pulse narrowing. Such features have applications in the domain of telecommunication technology.