One of the most important applications of stimulated Raman scattering (SRS) is the realization of amplifiers or laser sources in bulk materials, in fiber and in integrated optic format as well. We note that, as a general rule, in all laser gain bulk materials, there is a tradeoff between gain and bandwidth: line width may be increased at the expense of peak gain. This tradeoff is a fundamental limitation toward the realization of micro/nano-sources with large emission spectra. In this paper, in order to clarify the possibility of obtaining new materials with both large Raman gain coefficients and spectral bandwidth, SRS investigations in nanostructures, spanning from nanometrically heterogeneous K2O–Nb2O5SiO2 (KNS) glasses to Si nanocrystals, are reported and discussed.
Design of a Monolithic Low-Threshold Narrow-Linewidth CW Mid-IR Silicon Raman Laser