New Terahertz Laser Lines From $^{13}{\hbox {CD}}_{3}{\hbox {OH}}$ Pumped by Regular and Hot Bands ${\hbox {CO}}_{2}$ Laser

We have used our new pulsed CO
₂
laser, operating both on regular and hot bands, to excite the
¹³
CD
₃
OH methanol isotopomer. This has lead to the observation of 13 new high-threshold far-infrared laser emissions (also identified as terahertz laser lines), with frequencies in the range between 24.11 and 102.56 cm
^-1
(0.72-3.07 THz). The absorption transitions leading to these new FIR laser emissions have been located by observing the optoacoustic absorption spectra around the CO
₂
emissions. Here, we present these new far-infrared laser lines, characterized in wavelength, polarization, offset relative to the center of the pumping CO
₂
laser transition, relative intensity, and optimum operation pressure.