Raman amplification based on stimulated Stokes Raman scattering (SSRS) and wavelength conversion based on coherent anti-Stokes Raman scattering (CARS) are theoretically investigated in silicon-on-sapphire (SOS) waveguides in the mid-infrared (IR) region. When the linear phase mismatch 1k is close to zero, the Stokes gain and conversion efficiency drop down quickly due to the effect of parametri...

We theoretically study the problem of Raman gain maximization in uniform silicon photonic-crystal waveguides supporting slow optical modes. For the first time, an exact solution to this problem is obtained within the framework of the undepleted-pump approximation. Specifically, we derive analytical expressions for themaximum signal gain, optimal input pump power, and optimal length of a silicon...

A controllable self-Raman laser using an adaptive optics (AO)-based control loop featuring an intracavity deformable mirror is reported. This method has the potential to alleviate thermal lensing within the Raman and laser gain media, and enable solid-state Raman lasers to reach new power levels. A proof-of-concept experiment using a Nd:YVO4 self-Raman laser and resulting in 18% enhancement of ...

Wavelength tunable synchronous pulse sources are highly desirable for spectroscopy and optical diagnostics. The common method to generate short pulses in the fiber is the use of nonlinear induced spectral broadening which result in soliton shaping in anomalous dispersion regime. However, to generate ultra-short pulses, broadband gain mechanism is also required. In recent years, Raman fiber lase...

Coupled-mode theory is used to calculate Raman gain and spontaneous efficiency in silicon waveguides with cross-sectional areas ranging from 0.16 to 16 microm2. We find a monotonic increase in the Raman gain as the waveguide cross section decreases for the range of dimensions considered. It is also found that mode coupling between the Stokes modes is insignificant, and thus polarization multipl...

Random lasers are a developing class of light sources that utilize a highly disordered gain medium as opposed to a conventional optical cavity. Although traditional random lasers often have a relatively broad emission spectrum, a random laser that utilizes vibration transitions via Raman scattering allows for an extremely narrow bandwidth, on the order of 10 cm(-1). Here we demonstrate the firs...

The Raman pumps consist of 90 mW backward-propagating 1495 nm polarisation multiplexed pumps for the longer wavelength region, along with forward and backward 1410 nm polarisation multiplexed pumps for the shorter wavelength region. The 1410 nm forward pump is 150 mW and the backward pump is 2 10 mW. 50 km of nonzero dispersion shifted fibre with roughly 14.3 dB attenuation is used for transmis...

In this work, by means of numerical simulations, we verify that four-wave mixing (FWM) processes, including depletion and parametric gain, generate a redistribution of pump power in distributed fiber Raman amplifiers (DFRAs). As a consequence of pump-pump FWM, FWM products are generated, as well as a power exchange between pumps, which produces degradation in the performance of the amplifier du...