Mid-infrared generation by difference frequency generation of CW fiber laser

Abstract

Periodically poled congruent lithium tantalite (PPCLT) and periodically poled congruent lithium niobate (PPCLN)-based quasi phase matched (QPM) difference frequency generation (DFG) conversion systems are developed for inclusion in a mid-IR spectrometer providing a wavelength tunable and efficient conversion solution. Using two continuous wave (CW) fiber lasers the conversion efficiency of DFG CLT chip is over 0.1%, while with an 8cm long DFG CLN chip is over 1%. This conversion is higher than any reported in the literature.