Multiple path infrared laser source using difference frequency generators

A method or an apparatus for laser frequency conversion comprising first laser 102 generating low power continuous light with wavelength g 1, second laser 104 generating low power continuous light with wavelength g 2, third laser 106 generating high power pulsed light with wavelength g 0, sending light with wavelength g 1 and light with wavelength g 0 to first Difference Frequency Generator (DFG) 110, sending light with wavelength g 2 and light with wavelength g 0 to second DFG 112, sending light output from first DFG 110 and second DFG 112 to third DFG 114 and fourth DFG 116 to generate high power pulsed light with wavelengths g 3 and g 3DFG and combining both wavelengths in beam splitter 118 to form a single beam. The apparatus 100 may be used as a tunable high power Long Wave Infrared (LWIR) source for detecting hazardous nitrogen compounds using laser induced breakdown spectroscopy (LIBS). Lasers 1, 2 may be tunable lasers generating narrow line width light. Reflective mirrors 108a and dichroic beam splitters 108b-108k may direct, separate or combine beams of different wavelengths.