Terahertz Raman laser based on silicon doped with phosphorus

Raman-type stimulated emission at frequencies between 5.0 and 5.2 THz as well as between 6.1 and 6.4 THz has been realized in silicon crystals doped by phosphorus donors. The Raman laser operates at around 5 K under optical excitation by a pulsed, frequency-tunable infrared free electron laser. The frequencies of the observed laser emission are close to the frequencies of the intracenter laser lines which originate from the 2p(0) and 2p(+/-) phosphorus states. The Stokes shift of 3.16 THz is equal to the difference between the energies of the phosphorus ground state, 1s(A(1)), and the 1s(E) excited state. (C) 2008 American Institute of Physics.