Infrared pulses are generated via difference frequency mixing of Nd: glass laser pulses and infrared dye laser pulses. Tuning between 4 and 18 mum is achieved by various combinations of laser dyes (dye No. 5 and A 9860) and nonlinear crystals (AgGaS2 and GaSe). The energy of the mid-infrared pulses is in the order of a muJ; the photon conversion efficiency is less then or similar to 2%. The duration of the nearly bandwidth limited pulses is measured to be 1 ps. The system operates with a repetition rate of 1 Hz.