Efficient generation of infrared picosecond pulses from 10 to 20 microm

Starting with 11-ps pulses of 8-mJ energy at 1.064 microm and using a sequence of a KTP crystal and a CdSe crystal, we generate infrared pulses from 10 to 20 microm with energies ranging from 40 to 5 microJ. The quantum efficiency of the last stage is higher than 50% from 10 to 18 microm.