The /sup 13/CH/sub 3/OH optically pumped far-infrared laser: new lines and frequency measurements

We report 18 new laser lines from /sup 13/CH/sub 3/OH generated in an optically pumped far-infrared laser; the laser lines are in the range of 54.2-420 /spl mu/m and are all characterized in wavelength, polarization relative to the pumping CO/sub 2/ radiation, and pump offset relative to the CO/sub 2/ center frequency. The frequencies of seven of these new lines along with 10 previously reported lines were measured by an accurate heterodyne technique, mixing them in a metal-insulator-metal (MIM) point contact diode, with another laser line of known frequency.