A hybrid C+L band erbium-doped fiber amplifier/Raman fiber amplifier (EDFA/RFA) is constructed by sharing common 1480 nm pump source(s). It is based on three-level amplification mechanism in the C band and Raman shift amplification mechanism the in L band, respectively. The gain spectra of C+L band are flattened by optimally dividing the pump power ratio of 1:29 for EDFA/RFA. Gain variation is ...

We consider the Raman amplification problem for silicon waveguides in the regime in which both the pump and signal pulses are relatively short but wide enough that their duration exceeds the phonon lifetime (about 3 ps in silicon). We use the coupled pump-signal equations for numerical simulations that include all competing nonlinear effects such as selfand cross-phase modulations, two-photon a...

We study how coherent Stokes and anti-Stokes Raman scattering influence coherent population trapping. In an experiment using an atomic sodium vapor cell we observe induced transparency, induced absorption, and gain features, all of subnatural linewidth. The electromagnetically induced resonance is a peak or a dip depending on which side of the optical transition the fields are tuned to, and thu...

Introduction: Cladding-pumped rare-earth-doped fibers and Raman fiber devices have been two of the most compelling advances in the area of fiber amplifiers and lasers in recent years. Both cladding-pumped fibers and Raman fiber devices are primarily high-power devices. Cladding-pumping enables pumping with multi-mode pump sources that deliver high-power at a low cost. The core of the double-cla...

We report increased wavelength options from Raman lasers for Raman media having two Raman modes of similar gain coefficient. For an external-cavity potassium gadolinium tungstate Raman laser pumped at 532 nm, we show that two sets of Stokes orders are generated simultaneously by appropriate orientation of the Raman crystal, and also wavelengths that correspond to sums of the two Raman modes. Up...

We present approximate analytical expressions describing nonlinear interaction of two optical waves copropagating inside a silicon waveguide in the presence of linear losses, stimulated Raman scattering, and free-carrier absorption. Our approach avoids the undepleted-pump approximation, which we show to be inadequate to describe accurately the Raman-gain process. Based on our calculations, we p...

Physics) TWO-PHOTON RAMAN GAIN IN A LASER DRIVEN POTASSIUM VAPOR by

We report the optical injection modulation of semiconductor lasers by intra-cavity stimulated Raman scattering. This mechanism manifests itself as sharply enhanced modulation bandwidth in InAs/InGaAlAs/InP quantum-dash lasers when the injected photons are 33 +/- 3 meV more energetic than the lasing photons. Raman scattering measurements on the quantum-dash structure and rate equation models str...