Abstract
In this paper, some patents on silicon Raman amplifiers are investigated. These patents emphasize on the length reduction of amplifiers compared with the silica ones. However, the bandwidth of the amplifier in these patents is very low. In addition, while the pump wavelength is constant, the central frequency remains unchanged. The germanium doping leads to tuning of central frequency and bandwidth enhancement of Raman gain spectrum. Thus, the effect of germanium doping on the characteristics of major patents on silicon Raman amplifiers is investigated in this paper. Amplifier gain depends on various parameters such as the Raman gain coefficient. The effects of germanium doping on the impressive parameters of the silicon Raman amplifiers are also presented. By usage of the variable germanium concentration waveguides, the bandwidth of amplifiers is enhanced which has a great effect on communication systems. Furthermore, the characteristics of waveguide are estimated in order to achieve a flat gain amplification in silicon germanium on insulator (SiGe-OI) waveguides.
Keywords: Continuous wave pumping, free carrier absorption, free carrier lifetime, pulsed pumping, Raman amplification, ring resonator, silicon germanium (SiGe), two photon absorption, SiG-OI Waveguides, Frequency, SiGe Raman Amplifiers, Amplifiers, resonator, insulator, waveguides