Generation and detection of tunable ultrashort infrared and far-infrared radiation pulses of high intensity

We report on generation and detection of intense pulsed radiation with frequency tunability in the infrared and far-infrared spectral regions. Infrared radiation is generated with a transversally electrically excited high pressure CO₂ laser. A laser pulse of a total duration of about 300 ns consisted, due to self mode locking, of a series of single pulses, some with pulse durations of less than 450 ps and peak powers larger than 20 MW. Using these pulses for optical pumping of a Raman D₂O laser, trains of short far-infrared pulses with durations less than 400 ps were obtained. For detection a new ultrafast superconducting detector was used.