Stimulated Raman scattering in laser technology
Stimulated Raman scattering (SRS) is a third-order nonlinear optical effect that is used in laser technology either to shift the wavelength emission of a laser (‘Raman laser’) or to provide optical amplification of an input beam (‘Raman amplifier’). Since the early 2000s, Raman amplifiers have been widely used in optical fibres for telecom applications, such as long-haul fibre-optic transmission systems .
In the last few years, there has been an increasing interest in Raman laser technology. The recent demonstrations of nanowaveguide  and microresonator  silicon Raman lasers are an important step towards ‘photonic integrated circuits’. There has also been a number of reports on intracavity Raman lasers [4–5]. These are optical devices where the gain medium of the pump laser and the Raman-active material (typically a bulk crystal with a length of a few millimetres) are placed in the same resonator. The intracavity Raman laser has the potential to extend the spectral coverage of standard solid-state and semiconductor lasers, and allows for multi-wavelength operation via cascaded nonlinear conversion (e.g. frequency doubling or sum frequency mixing) using a single, compact device.
- Islam, M.N. (2002) “Raman amplifiers for Telecommunications” IEEE Journal of Selected Topics in Quantum Electronics, pp. 548-559 [Published online 7 August 2002]
- H., et al. (2013) “An all-silicon Raman laser” Nature 498, pp. 470–474 [Published online 26 June 2013]
- Takahashi, Y., et al. (2005) “A micrometre-scale Raman silicon laser with a microwatt threshold” Nature 433, pp. 292-294 [Published online 5 January 2005]
- Parrotta, D.C., et al. (2011) “Continuous-wave Raman laser pumped within a semiconductor disk laser cavity,” Lett.36, pp. 1083-1085
- Lee, A.J., et al. (2010) “A wavelength-versatile, continuous-wave, self-Raman solid-state laser operating in the visible,” Express18, pp. 20013-20018