Terahertz Raman laser from silicon doped by arsenic

Stimulated Raman emission at frequencies ranging from 4.8 THz to 5.1 THz and from 5.9 THz to 6.5 THz has been realized by optical excitation of arsenic donors in silicon. The Stokes shift is 5.42 THz, which is equal to the Raman-active donor electronic transition between the 1s(A₁) ground state and the excited 1s(E) state. In addition, intracenter donor lasing has been observed when pumping on the dipole-forbidden 1s(A₁)rarr2s transition.