  By introducing methyl fluoride (CH$_3$F) as a new gain medium for a quantum
cascade laser-pumped molecular laser (QPML), we demonstrate continuous-wave
lasing from more than 120 discrete transitions spanning the frequency range
0.25 to 1.3 THz. The unprecedented degree of spectral tuning achieved with
CH$_3$F also confirms the universality of the QPML concept: for all polar gas
molecules, lasing can be induced on any dipole-allowed rotational transition by
sufficient pumping of a related roto-vibrational transition using a
continuously tunable quantum cascade laser.
