CW submillimeter laser action in ethyl chloride

We present ten new far-infrared (FIR) laser lines obtained by optically pumping ethyl chloride by means of a CW waveguide CO/sub 2/ laser with a tunability range of 300 MHz. By means of a heterodyne technique and using, as mixing element, a metal-insulator-metal (MIM) point contact diode or a new home built metal-semiconductor diode, we measured the frequency of all these new lines, as well as that of another line, previously reported in literature. With our new lines, the total number of FIR laser lines emitted by ethyl chloride rises to 14; for each of them we give the offset relative to the center frequency of the pumping radiation, the polarization relative to that of the pumping CO/sub 2/ laser, the relative intensity, and the optimum operation pressure. Seven of the new lines have frequencies in the 300-512-GHz range and four of them are strong enough to be used in high-field EPR spectroscopy.