CW SUBMILLIMETER LASER ACTION IN ETHYL CHLORIDE

We present ten new far-infrared (FIR) laser lines obtained by opticall y pumping ethyl chloride by means of a CW waveguide CO2 laser with a t unability range of 300 MHz, By means of a heterodyne technique and usi ng, as mixing element, a metal-insulator-metal (MIM) point contact dio de or a new home built metal-semiconductor diode, we measured the freq uency of all these new lines, as well as that of another line, previou sly reported in literature, With our new lines, the total number of FI R 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 rad iation, the polarization relative to that of the pumping CO2 laser, th e 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.