Laser stark spectroscopy of13CH3F

The far-infrared laser Stark spectrum of13CH3F has been observed using the 190 μm line of the DCN laser. The spectrum was taken at room temperature for both parallel and perpendicular polarizations up to 60,000V/cm. We identify the transition as Jk=3214←3114 in the ground vibrational state. The measured zero-field frequency for this transition is in agreement with that calculated from the available molecular constants.