The first demonstration of light amplification in silicon represents a significant milestone towards producing fully integrated monolithic photonic chips. Stimulated Raman scattering has been used to demonstrate light amplification and lasing in silicon. The nonlinear optical loss associated with two-photon absorption (TPA)-induced free carrier absorption (FCA) is the main limitation to amplify the laser. With introducing a reverse-biased p-i-n diode embedded in a ridge silicon waveguide

when a reverse bias voltage is applied to the p-i-n diode

the TPA-generated electron-hole pairs can be swept out of the silicon waveguide by the electric field between the p- and n-doped regions. Thus the effective carrier lifetime

representing the lifetime of the free carrier's interaction with the optical mode in the waveguide region

reduces with increasing bias voltage. Because the technics on silicon has been very mature and apparatus made in silicon is very smart

it is a good method to apply the silicon as the waveguide to reduce the volume of laser amplifier. There is no restrict of pump power resource for the Raman laser amplifier based on silicon waveguide. It also possess further higher saturate power. We design a new type of Raman laser amplifier based on silicon waveguide by coating the transmissive film to the cleavage of silicon waveguide according to the Fabry-Perot resonance technique and traveling wave amplifier theory. The Raman gain coefficient can be controlled by the reverse bias voltage on the silicon waveguide

and the amplified signal light wavelength responses to the pump light wavelength in the Raman laser amplifier. The lifetime of photo-generated carriers in silicon-on-insulator rib waveguides is studied in connection with the optical loss produced via nonlinear absorption. We present an analytical model about the Raman gain by using the conclusion that effective carrier lifetimes of 1 ns can be obtained in waveguides resulting in negligible nonlinear absorption. The Raman gain and output power of the amplifier is calculated by the equation we constructed. For a 4.8 cm long waveguide with an effective core area of ~1.6μm

2

and a reverse bias voltage of 25 V

we obtained a net gain of 2.6 dB with a pump laser wavelength of 1536 nm and a pump power of 600 mW inside the waveguide. Raman gain can be raised by increasing the waveguide length and pump power properly.