We present innovative structures for ring-based Raman amplifier with two separate entrances for the pump and signal. In this way, only the pump is coupled into the ring and the signal passes directly through the path that the amplified pump is propagating inside the ring without a destructive effect on signal pulse. Using engineered nanoholes filled with optofluidic material in the signal and pump paths, we reduce pump and signal group velocity to improve the structure and achieve larger Raman gain. The time evolution and propagation of picosecond signal pulses and dispersion inside the device are analyzed. Maxwell equations are solved using finite difference time-domain method considering optical nonlinear parameters like two photon absorption, free-carrier absorption, and Kerr effect.