pushed to such high power levels that it acts itself as the pump for the generation of "second-order" laser light that is shifted by the same vibrational frequency again. In this way, a single laser resonator is used to convert the pump light (typically around 1060 nm) through several discrete steps to an "arbitrary" desired output wavelength. Silicon Raman lasers More recently, Raman lasing has been demonstrated in silicon-based integrated-optical waveguides by Bahram Jalali's group at the University of California in Los Angeles in 2004 (pulsed operation) and by Intel in 2005 (continuous-wave), respectively. These developments received much attention because it was the first time that a laser was realized in silicon: "classical" lasing based on electronic transitions is prohibited in crystalline silicon due to its indirect bandgap. Practical silicon-based light sources would be very interesting for the field of silicon photonics, which seeks to exploit silicon not only for realizing electronics but also for novel light-processing functionality on the same chip. See also Raman amplification C. V. Raman References External links "Raman Lasers", in the Encyclopedia of Laser Physics and Technology Laser science Raman scattering