Abstract
Raman amplifiers are important for optical communication because the power of signal gradually reduces along propagation. We must use amplifiers to recover signal power strong enough for defection. A Raman amplifier is one kind of amplifiers. The Raman coefficient in silicon is much higher than in fiber(10000 times),and it is a reason that we are interested using silicon waveguides to make a amplifier. The size of silicon Raman amplifiers is very small and can be integrated with other devices to accomplish many optical functions on a chip. In this thesis, we take advantage of high Raman coefficient in silicon and utilize resonant enhancement of microring resonators to make Raman amplifiers on silicon-on-insulator. In order to have better waveguide-fiber coupling, we use multimode waveguides and apply micro-electro-mechonical-system (MEMS) technology to allow waveguide and microring well coupled. In measurement, we observe spontaneous and stimulation Raman scattering by controlling the input power. When input power is higher, we also discover the free carrier effect affecting the signal power and refractive index of waveguide. However the loss of device is too high and we can’t adjust the power coupling ratio,causing that Raman effect is not obvious. To improve the efficiency of device, we could use a novel low-loss silicon photonic wire to make our device in the future. The novel low-loss silicon photonic wire has advantages in low loss and single guide mode. So we expect that it can be better than multimode waveguide and maybe generates Raman laser.